Cells and Membranes Practice Exam, Biology Chapter 3 Study Test Questions, Biology Chapter 4 Study Test Questions, Biology Chapter 5 Study Test Questions, Biology Chapter 4 Study Test Questions, Biology Chapter 9 Study Test Questions, Biology Chapter...
43) Antibiotics can be effective only against a A) viroid. B) virus. C) bacterium. D) prion.
C) bacterium
19) The process of meiosis
C) begins with diploid cells and ends with haploid cells.
71) Which disorder is the most common chromosome anomaly among newborns?
E) Down syndrome
64) The discovery of the organism Thermus aquaticus was critical for the development of the technique of PCR.
TRUE
Active transport requires all of the following EXCEPT:
aquaporins.
Which process accounts for the movement of solids into some animal cells?
phagocytosis.
70) Which disorder is more common among the babies of older mothers?
E) Down syndrome
61) In eukaryotic cells, chromosomes are composed of both DNA and proteins.
TRUE
61) Some archaea can live in boiling water.
TRUE
63) Scientific experimentation generally leads to more questions.
TRUE
63) The two strands of DNA are held together by hydrogen bonds.
TRUE
64) Humans can eat live cultures of some bacteria without getting sick.
TRUE
The internal solute concentration of a plant cell is about 0.8 M. To demonstrate plasmolysis, it would be necessary to suspend the cell in what solution? (eText Concept 7.3) * 0.4 M * distilled water * 1.0 M * 0.8 M * 150 mM.
1.0 M
The slowest rate of diffusion of dye particles in water will occur at:
10 degree Celsius
30) All of the following combinations are possible in the gametes of an organism that is AaBb EXCEPT
A) aa.
1) Scientific inquiry is based on A) natural causes. B) information found in a gossip magazine. C) stories that are passed down through generations. D) cultural biases or traditions.
A
15) Which of the following statements is a hypothesis rather than a theory? 15) A) Female birds prefer to mate with male birds that have longer tails. B) Matter is composed of atoms. C) Living things are made of cells. D) Modern organisms descended from preexisting life-forms.
A
24) Evolution is sometimes described as the change from preexisting life-forms to modern-day organisms. What actually changes in every case of evolution is the A) genetic makeup of the species due to mutations. B) ability of organisms to respond to external stimuli. C) energy and nutritional demands of the organism. D) species' physical appearance. E) rate of reproduction.
A
29) In a word "evolution" means A) change. B) improvement. C) selection. D) nature.
A
44) Using its antennae the male moth finds female moths by following a trail of airborne chemicals called pheromones upwind from the female producing them. This is an example of how living things A) detect and respond to stimuli. B) reproduce. C) maintain precise internal conditions. D) acquire nutrients. E) grow.
A
46) Why do heterotrophs require "food" for survival? A) Food provides the organic chemicals needed by heterotrophs. B) Food provides at least half of the water required by heterotrophs. C) Food is an alternative source of energy for heterotrophs when sunlight is unavailable. D) Heterotrophs cannot photosynthesize without the chemicals provided by food.
A
49)A puppy is born weighing 5 pounds and eventually becomes a 75-pound golden retriever.
A
50)At the beginning of the week, a plant is 3 inches tall and at the end of the week, it is 4 inches tall.
A
52) A bacterium divides into two bacteria that are identical to, but smaller than, the original bacterium.
A
55) In evolutionary terms, which of the following cells is considered to be the most primitive? A) Prokaryote B) Heterotroph C) Autotroph D) Eukaryote
A
57) A basic difference between a prokaryotic cell and a eukaryotic cell is that the prokaryotic cell A) lacks a nucleus. B) is considerably larger. C) possesses membrane-bound organelles. D) lacks DNA. E) is structurally more complex.
A
6) The scientific method includes all of the following EXCEPT 6) A) a testable theory. B) a hypothesis. C) an observation. D) conclusions. E) experimentation.
A
73) Suppose that a meteorite crashes into Earth and a sample of it is taken to a local research lab for 91) analysis. Embedded several inches within the rocky structure, a microscopic cluster of dormant, spore-like structures is found. The scientists culture some of this material in a standard microbiological nutrient broth, and they are surprised to find many single-celled "organisms" moving around, growing, and reproducing in the broth. The "organisms" behave the same in both daylight and dark conditions, do not require oxygen, and thrive under a wide range of temperatures and pH levels. They stop moving, growing, and reproducing, however, when fewer nutrients are available in the medium. In this scenario, the "organisms" most closely resemble a(n) A) heterotrophic species of Archaea. B) autotrophic species of Eukarya. C) heterotrophic species of Eukarya. D) nonliving virus. E) photosynthetic species of Bacteria.
A
Green olives may be preserved in brine, which is a 30% salt solution. How does this method of preservation prevent microorganisms from growing in the olives? (eText Concept 7.3) * High salt concentration lowers the pH, thus inhibiting bacterial metabolism. * Bacterial cells shrivel up in high salt solutions, causing the cell to burst. * A 30% salt solution is hypertonic to the bacteria, so they lose too much water and plasmolyze. * A 30% salt solution is hypotonic to the bacteria, so they gain too much water and burst. * High salt concentration raises the pH, thus inhibiting bacterial metabolism.
A 30% salt solution is hypertonic to the bacteria, so they lose too much water and plasmolyze.
16) The sequence of subunits in the DNA "backbone" is
A) -phosphate-sugar-phosphate-sugar-phosphate-sugar-.
27) A typical human body cell contains how many sex chromosomes?
A) 2
13) How many bases are in a codon? A) 3 B) 64 C) 20 D) 4
A) 3
7) How many consecutive mRNA bases are needed to specify an amino acid? A) 3 B) 20 C) 64 D) 4
A) 3
59) DNA polymerase always moves from ________ along the strand resulting in DNA replication to be continuous on one strand and discontinuous on the other.
A) 3' to 5' B) base to phosphor group
65) If a parent cell has 16 chromosomes, how many sister chromatids will be present after duplication of the chromosomes?
A) 32
33) From the beginning of glycolysis to the end of the Krebs cycle (excluding the ETC), what has the cell gained from the breakdown of each molecule of glucose?
A) 4 molecules of ATP, 10 of NADH, and 2 of FADH2
7) During aerobic respiration in cells, about ________ of the chemical energy in a metabolized glucose molecule is used for ATP production and the rest is released as heat.
A) 40% B) 8) If no oxygen is available to a cell, then the net ATP production resulting from the metabolism of a single glucose molecule is A) 2 ATP molecules.
45) A recessive allele on the X chromosome causes color deficiency. A noncolor-deficient woman (whose father is color deficient) marries a color-deficient man. If they have a son, what is the chance that he will be color deficient?
A) 50%
60) If an individual who is homozygous for type B blood marries a heterozygous type A individual, what is the chance that their first child will have type AB blood?
A) 50%
66) At the end of aerobic cellular respiration, how many total carbon dioxide molecules are produced for each glucose metabolized?
A) 6
25) Which of the following is NOT true according to Chargaff's base pairing rule?
A) A + T = G + C in amount.
2) Which of the following statements does NOT agree with the cell theory? A) A balanced diet is important for good health. B) The smallest living organisms are single cells. C) Spontaneous generation of cells cannot occur. D) Paramecium comes from Paramecium. E) Insects are composed of cells.
A) A balanced diet is important for good health
3) What is the relationship among DNA, a gene, and a chromosome?
A) A chromosome contains hundreds of genes, which are composed of DNA.
38) Independent assortment refers to which of the following statements?
A) A maternal chromosome may move toward either pole while the paternal homologue moves toward the other.
53) Blood typing is often used as evidence in paternity cases in court. In one case, the mother had blood type B and the child had blood type O. Which of the following blood types could the father NOT have?
A) AB
33) Suppose one strand of a "mini-gene" has the base sequence TACCCGGATTCA. The last codon in the mRNA sequence will be A) AGU. B) AGT. C) TCA. D) UGA.
A) AGU.
39) The products of the Krebs cycle include
A) ATP, carbon dioxide, and energy carriers.
30) Chemiosmosis in mitochondria directly results in the synthesis of
A) ATP.
30) Which of the following is an energy-requiring mode of transport that brings substances into a cell? A) Active transport B) Facilitated diffusion C) Osmosis D) Simple diffusion
A) Active transport
58) The cytoplasm of a certain cell, such as a neuron, already has a high concentration of K + ions. How can K+ ions continue to enter the cell? A) Active transport B) Exocytosis C) Facilitated diffusion D) Infusion E) Osmosis
A) Active transport
66) Which of the following requires adenosine triphosphate? A) Active transport B) Osmosis C) Facilitated diffusion D) Simple diffusion
A) Active transport
17) When Mendel used true-breeding white flowers and true-breeding purple flowers as the parental generation, what were the results? (Purple flower is dominant over white.)
A) All of the offspring had purple flowers.
74) Which of the following cell cycles is represented by ferns and other plants?
A) Alternation of generations
56) Which of the following techniques is most commonly used in the prenatal diagnosis of genetic disorders, such as cystic fibrosis, in a human fetus? A) Amniocentesis B) Isolation of fetal cells from maternal blood C) Chorionic villus sampling
A) Amniocentesis
79) During which phase of mitosis do sister chromatids separate from each other?
A) Anaphase
83) Which phase of mitosis involves the shortening of the microtubules as the chromosomes move toward the poles?
A) Anaphase
8) How do the flagella of bacteria differ from the flagella of archaea? A) Archaeal flagella are thinner than bacterial flagella. B) Bacterial flagella cannot rotate. C) Bacterial flagella occur at only one end of the cell. D) The flagella of archaea are scattered over the cell surface. E) Bacterial flagella are used for reproduction.
A) Archaeal flagella are thinner than bacterial flagella.
30) ________ are used in the production of foods such as yogurt, cheese, and sauerkraut. A) Bacteria B) Viroids C) Viruses D) Eukaryotes E) Protists
A) Bacteria
2) What is the term for manipulating the molecular basis of inheritance via recombinant DNA technology? A) Biotechnology B) Mendelian genetics C) DNA fingerprinting D) Restriction fragment length polymorphism (RFLP) E) Polymerase chain reaction (PCR)
A) Biotechnology
28) Lyme disease is caused by A) Borellia burgdorferi. B) rats. C) contaminated water. D) Clostridium botulinum. E) nitrogen-fixing bacteria.
A) Borellia burgdorferi.
24) Which of the following can serve as an energy source and as structural support in plant cells? A) Carbohydrates B) Nucleic acids C) Proteins D) Lipids
A) Carbohydrates
25) Which of the following categories includes monosaccharide monomers? A) Carbohydrates B) Proteins C) Nucleic acids D) Lipids
A) Carbohydrates
45) Which pair of organelles is responsible for supplying energy (in the form of ATP) to eukaryotic cells? A) Chloroplasts and mitochondria B) Ribosomes and mitochondria C) Mitochondria and lysosomes D) Chloroplasts and ribosomes E) Golgi apparatus and ribosomes
A) Chloroplasts and mitochondria
59) Which of the following does NOT provide new genetic combinations?
A) Cytokinesis
19) What primarily determines the shape of animal cells, which lack cell walls? A) Cytoskeleton B) Nucleus C) Endoplasmic reticulum D) Ribosomes E) Cytoplasm
A) Cytoskeleton
12) Which of the following is so small, it is visible only with an electron microscope? A) DNA B) Mitochondrion C) Eukaryotic cell D) Prokaryotic cell
A) DNA
24) Through which process do bacteria recycle nutrients in the environment? A) Decomposition B) Endospore formation C) Conjugation D) Photosynthesis E) Binary fission
A) Decomposition
64) Your friend is trying to learn about how to kill bacteria. She reads that preservatives such as citric 64) acid are added to foods because the acidic environment kills bacteria by denaturing their proteins. She thinks this sounds like a lot of scientific jargon and asks you what it means. How can you explain it in simpler terms? A) Denaturing means that the proteins of the bacteria lose their structure and can't function, so the bacteria die. B) Denaturing refers to the fact that the bacterial cells divide too quickly and die. C) The acid causes the cells to swell and burst open, also known as denaturation. D) Denaturing their proteins means that the proteins in bacteria are converted into carbohydrates
A) Denaturing means that the proteins of the bacteria lose their structure and can't function, so the bacteria die.
64) Which of the following is TRUE regarding gene expression? A) Different tissues within an organism express different genes. B) Different individuals of the same species express all of the same genes. C) Gene expression is not influenced by the environment. D) Gene expression remains constant throughout an organism's life span.
A) Different tissues within an organism express different genes.
29) Regarding the structure of DNA, which of the following is like a spiral staircase?
A) Double helix
24) The metabolic breakdown of one molecule of glucose generates the greatest amount of ATP energy during
A) ETC.
40) Which of the following occurs as an enzyme produced by a cell is secreted from the cell? A) Exocytosis B) Receptor-mediated endocytosis C) Pinocytosis D) Phagocytosis E) Endocytosis
A) Exocytosis
17) Which of the following is NOT a function of plastids? A) Extracting energy from food and converting it to ATP B) Storing pigments C) Storing photosynthetic products D) Carrying out photosynthesis
A) Extracting energy from food and converting it to ATP
31) When 1 gram of each of these food sources is consumed, which yields the greatest amount of energy in calories? A) Fat B) Phenylalanine C) Sucrose D) Glucose E) Polypeptide
A) Fat
53) During which of the following processes is ATP NOT produced?
A) Fermentation by itself
18) Free radicals contain unpaired electrons in their outermost energy shell, so they react readily with 18) other atoms or molecules to reach a more stable state. Which of the following could potentially be a free radical? A) Fluorine (atomic number 9) B) Magnesium (atomic number 12) C) Helium (atomic number 2) D) Neon (atomic number 10)
A) Fluorine (atomic number 9)
62) How many daughter cells are produced from each parent cell during meiosis?
A) Four
5) Of the items listed, which is the smallest that you can see with the unaided eye? A) Frog embryo B) Ribosomes C) Human skin cell D) DNA molecule E) Virus
A) Frog embryo
43) Which of the following processes occurs in the cytoplasm?
A) Glycolysis
52) Which of the following is common to both fermentation and cellular respiration?
A) Glycolysis
54) Sorts proteins and sends them to their proper destination
A) Golgi apparatus
52) Which of the following occurs as a result of meiosis?
A) Haploid nuclei with unpaired chromosomes are produced from diploid parent nuclei with paired chromosomes.
60) Which of the following occurs during meiosis?
A) Haploid nuclei with unpaired chromosomes are produced from diploid parent nuclei with paired chromosomes.
51) Which of the following is unique to mitosis and not a part of meiosis?
A) Homologous chromosomes behave independently.
53) What maintains the secondary structure of a protein? A) Hydrogen bonds B) Disulfide bonds C) Peptide bonds D) Ionic bonds
A) Hydrogen bonds
69) How does anaphase of mitosis differ from anaphase I of meiosis?
A) In anaphase of mitosis, sister chromatids separate, but in anaphase I of meiosis, homologous chromosomes separate.
32) What does mRNA carry away from the nucleus? A) Information B) tRNA C) Enzymes D) Ribosomes E) Amino acids
A) Information
44) Four of the five answers listed below are stages of actual nuclear division. Select the exception.
A) Interphase
29) What type of bond is easily disrupted in aqueous solutions (one in which the solvent is water)? 29) A) Ionic B) Covalent C) Polar covalent
A) Ionic
94) What causes the rhythmic change in cyclin concentration in the cell cycle?
A) Its destruction by an enzyme phosphorylated by the cyclin-Cdk complex
72) Which of these is NOT a nucleic acid or nucleotide? A) LDL B) RNA C) DNA D) ATP
A) LDL
35) How does a cell rid itself of defective or malfunctioning organelles? A) Lysosomes assist in the removal of defective organelles by digesting them. B) The organelles are engulfed by plastids and stored. C) Defective organelles accumulate until the cell itself dies. D) The organelles are exported by phagocytosis. E) Ribosomes remove malfunctioning organelles by degrading the parts.
A) Lysosomes assist in the removal of defective organelles by digesting them.
97) Mitosis is controlled at the ________ checkpoint.
A) M
28) How many nucleotides are in a human chromosome?
A) Millions
37) The fat substitute Olestra contains a sucrose backbone with six to eight fatty acids attached. How is this different from a naturally occurring fat? A) Naturally occurring fats contain a glycerol and three fatty acids. B) It isn't Olestra and natural fats have the same structure, just different tastes. C) Naturally occurring fats contain a glycerol, two fatty acids, and a phosphate group. D) Naturally occurring fats contain a sucrose backbone and three fatty acid chains.
A) Naturally occurring fats contain a glycerol and three
42) Which of the following is LEAST affected by the presence of water? A) Nonpolar covalent bond B) Polar covalent bond C) Ionic bond D) Hydrogen bond E) Electron-proton interaction
A) Nonpolar covalent bond
63) Four of the five answers listed below assist in chromosome movement. Select the exception.
A) Nuclear envelope
75) Which of these biological molecules contain genetic information? A) Nucleic acids B) Carbohydrates C) Lipids D) Proteins
A) Nucleic acids
77) A woman with blood type AB and a man with blood type O have three children, one of whom is adopted. The blood types of the children are A, B, and O. What is the blood type of the adopted child?
A) O
18) What does the bacterial genome consist of?
A) One circular DNA molecule
31) What is the final electron acceptor in cellular respiration?
A) Oxygen
29) Which of the following molecular techniques involves "DNA replication in a tube"? A) PCR B) STR C) Transformation D) Gel electrophoresis
A) PCR
73) What is the difference between phenotype and genotype?
A) Phenotype is the physical expression of a trait and genotype is the combination of alleles carried by the organism.
6) Which is NOT a typical site for the occurrence of meiosis?
A) Plant root cells
58) Which of the following refers to the amino acid sequence of proteins? A) Primary B) Secondary C) Tertiary D) Quaternary
A) Primary
59) Which is a difference between prokaryotes and eukaryotes? A) Prokaryotes have a nucleoid, whereas eukaryotes have a nucleus. B) Prokaryotes have a cell wall, but eukaryotes do not. C) Prokaryotes have DNA, whereas eukaryotes have RNA. D) Prokaryotes have a nucleus, whereas eukaryotes have a nucleoid. E) Prokaryotes have RNA, whereas eukaryotes have DNA.
A) Prokaryotes have a nucleoid, whereas eukaryotes have a nucleus.
80) Imagine that the short DNA base sequence GGCTGC is transcribed and then translated by a ribosome. The following activated tRNA molecules are available in the cytoplasm: tRNA Anticodon Amino Acid GGC proline CGU alanine UGC threonine CCG glycine ACG cysteine CGG alanine What resulting dipeptide will form? A) Proline-threonine B) Alanine-alanine C) Glycine-cysteine D) Threonine-glycine E) Cysteine-alanine
A) Proline-threonine
61) Which of the following biological molecules are composed of amino acid subunits? A) Proteins B) Lipids C) Carbohydrates D) Nucleic acids
A) Proteins
62) Which of the following may possess primary, secondary, tertiary, and quaternary structures? A) Proteins B) Carbohydrates C) Nucleic acids D) Lipids
A) Proteins
19) How can RNA be distinguished from DNA? A) RNA is single-stranded. B) RNA does not contain a sugar. C) RNA is never found in the nucleus. D) RNA lacks the base uracil.
A) RNA is single-stranded.
39) A virus basically consists of A) RNA or DNA and a protein coat. B) RNA or DNA and a membrane. C) proteins and a cell membrane. D) RNA or DNA and enzymes. E) enzymes and a protein coat.
A) RNA or DNA and a protein coat.
10) The genetic material of some viruses, such as HIV, is not DNA but is instead A) RNA. B) lipid. C) protein. D) carbohydrate.
A) RNA.
26) Which of the following types of membrane proteins are responsible for conveying external messages such as those sent by a hormone signal? A) Receptor proteins B) Transport proteins C) Connection proteins D) Recognition proteins E) Enzymes
A) Receptor proteins
22) Which of the following does NOT possess a double membrane? A) Ribosome B) Chloroplast C) Plastid D) Nuclear envelope E) Mitochondrion
A) Ribosome
36) Which statement most accurately describes the interactions among ER, ribosomes, and Golgi bodies in exporting protein from the cell? A) Ribosomes manufacture proteins, which travel through the ER and are packaged by the Golgi bodies for export. B) Ribosomes make proteins that travel through the Golgi bodies to the ER, which exports them. C) ER manufactures proteins, which are carried by ribosomes to the Golgi bodies for export. D) Golgi bodies manufacture proteins, which travel through the ER to be packaged by the ribosomes for export. E) ER manufactures proteins, which are carried by the Golgi bodies to the ribosomes for export.
A) Ribosomes manufacture proteins, which travel through the ER and are packaged by the Golgi bodies for export.
23) Which of the following is currently used by the U.S. Department of Justice as a form of genetic "fingerprints" of criminals? A) STRs B) PCRs C) The number of introns in a chromosome D) The genes responsible for producing the unique patterns of swirls and loops on a person's fingers E) Plasmids
A) STRs
12) Which of the following is NOT an example of genetic recombination between different species in nature? A) Sexual reproduction B) Viruses that transfer DNA between host organisms C) Bacterial transformation D) Bacteria that acquire foreign plasmids
A) Sexual reproduction
21) Some organisms are capable of asexual or sexual reproduction. Under favorable conditions, reproduction proceeds asexually. When conditions become more stressful, reproduction switches to a sexual mode. Why?
A) Sexual reproduction produces individuals with new combinations of recombined chromosomes increasing diversity.
23) Which of the following plants contains nitrogen-fixing bacteria in its root nodules? A) Soybeans B) Oranges C) Corn D) Potatoes E) Tomatoes
A) Soybeans
21) Which of the following provides long-term energy storage for plants? A) Starch B) ATP C) Glycogen D) Glucose E) Cellulose
A) Starch
59) What kind of mutation occurs when one base is changed to another at a single location in the DNA? A) Substitution B) Deletion C) Neutral D) Insertion
A) Substitution
22) If a mammal is born without the ability to produce EGF (epidermal growth factor), then its
A) ability to increase cell division when needed would diminish.
90) What occurs immediately following cytokinesis?
A) The G1 portion of interphase
43) What happens when hydrochloric acid (HCl) dissociates in pure water? A) The HCl molecules separate into H+ and Cl- ions. B) The pH of the solution increases. C) The HCl molecules float on top of the water. D) The water has a decrease of H+ ions. E) The concentration of OH- ions increases.
A) The HCl molecules separate into H+ and Cl- ions.
28) If all of the lysosomes within a cell suddenly ruptured and released their contents, what could occur? A) The biological molecules in the cell would begin to degrade. B) The number of proteins in the cell would begin to increase. C) There would be no change in the normal function of the cell. D) The DNA within the mitochondria would begin to degrade. E) The mitochondria and chloroplasts would begin to divide.
A) The biological molecules in the cell would begin to degrade.
38) Which of the following is TRUE regarding the genetic information in the cells of your body?
A) The genetic information in almost all of your body cells is identical.
2) What was the most significant conclusion of Griffith's experiments with pneumonia in mice?
A) There is a substance present in dead bacteria that can cause a heritable change in living bacteria.
74) A child is born with dwarfism (tt). His parents are of normal height. Which of the following must be TRUE of the parents?
A) They are both heterozygous tall.
8) According to the fluid mosaic model of cell membranes, which of the following is a TRUE statement about membrane phospholipids? A) They form a viscous fluid through which proteins shift and flow. B) They are free to depart from the membrane and are dissolved in the surrounding solution. C) They have hydrophilic tails in the interior of the membrane. D) They frequently flip-flop from one side of the membrane to the other. E) They occur in an uninterrupted bilayer, with membrane proteins strictly anchored to the surface of the membrane.
A) They form a viscous fluid through which proteins shift and flow.
75) What is the function of centrioles?
A) They produce microtubules for the chromosomes to migrate along as they move to opposite poles of the cell.
27) What is the function of the histones that are found in a chromosome?
A) They provide support for the DNA to form into a supercoiled structure.
51) Which of the following binds to codons? A) Transfer RNA B) RNA polymerase C) Messenger RNA D) DNA
A) Transfer RNA
24) Which of the following types of membrane proteins are responsible for facilitated diffusion? A) Transport proteins B) Connection proteins C) Recognition proteins D) Enzymes E) Receptor proteins
A) Transport proteins
33) A single covalent chemical bond represents the sharing of how many electrons? 33) A) Two B) Three C) One D) Four E) Six
A) Two
35) How many different kinds of base pairings are in DNA?
A) Two
5) Which of the following is found in RNA but NOT in DNA? A) Uracil B) Phosphate groups C) Thymine D) Adenine E) Deoxyribose
A) Uracil
11) Which of the following is the smallest? A) Virus B) Prokaryotic cell C) Mitochondrion D) Eukaryotic cell
A) Virus
40) Which of the following consists of a protein coat surrounding a molecule of genetic material? A) Viruses B) Protists C) Archaea D) Bacteria E) Prions
A) Viruses
53) Two aqueous solutions are separated by a selectively permeable membrane that allows water to pass through but does not allow starch to pass through. Solution A is 10% starch and solution B is 5% starch. What will occur? A) Water will diffuse from solution B to solution A. B) Water will diffuse from solution A to solution B. C) Starch will diffuse from solution A to solution B. D) Starch will diffuse from solution B to solution A. E) Both water and starch will diffuse from solution B to solution A.
A) Water will diffuse from solution B to solution A.
25) The nucleus of a eukaryotic cell is characterized by A) a double membrane. B) a nonporous membrane. C) a triple-layer membrane. D) a single-layered membrane.
A) a double membrane.
99) The cell cycle is controlled in most cells by
A) a series of checkpoints.
3) The structure of DNA most resembles which of the comparisons below
A) a spiral staircase
18) The nitrogenous base uracil pairs with A) adenine. B) uracil. C) thymine. D) guanine. E) cytosine.
A) adenine.
1) Different, or alternative, forms of the same gene are called
A) alleles.
35) New government regulations require that foods containing trans fats be labeled appropriately. A trans fat is formed when food manufacturers turn liquid oils into solid fats by adding hydrogen to vegetable oils. This hydrogenation process produces a solid fat because adding the hydrogen A) allows the fatty acid chains to pack together more tightly. B) causes a phospholipid to form. C) forms a wax molecule. D) allows fats to form tertiary and quaternary structures.
A) allows the fatty acid chains to pack together more tightly.
47) A tRNA molecule brings ________ to the ribosome during protein synthesis. A) an amino acid B) mRNA C) a polypeptide D) RNA polymerase
A) an amino acid
73) While examining a hot spring, you find something you haven't seen before. It has a cell membrane, but the cell wall lacks peptidoglycan. It contains both DNA and RNA. The DNA is circular. It would be classified as a(n) A) archaea. B) fungus. C) bacterium. D) prion. E) virus.
A) archaea.
24) In prokaryotes, the daughter cells produced by prokaryotic fission
A) are, with the exception of random mutations, genetically identical to the parent cell.
62) Prokaryotes that are rod-shaped are called A) bacilli. B) cocci. C) spirilla. D) eukaryotes.
A) bacilli.
61) If you removed the sex pili from a bacterial cell, then the A) bacterium could no longer exchange DNA with other cells. B) bacterium could no longer swim. C) bacterium could no longer regulate the movement of molecules into and out of the cell. D) bacterium would dry out. E) shape of the bacterium would change.
A) bacterium could no longer exchange DNA with other cells.
50) Imagine that beaker A has a 10% sucrose solution, and beaker B has an 8% sucrose solution. This means that A) beaker A is hypertonic relative to beaker B. B) beaker A is isotonic relative to beaker B. C) beaker A is hypotonic relative to beaker B.
A) beaker A is hypertonic relative to beaker B.
54) Codominance occurs when
A) both of the alleles in a heterozygote are equally expressed phenotypically in an individual.
38) Two categories of organic compounds typically provide energy for living systems. Representatives of these two classes are A) carbohydrates and proteins. B) carbohydrates and lipids. C) proteins and nucleic acids. D) lipids and proteins. E) carbohydrates and nucleic acids.
A) carbohydrates and proteins.
21) Intestinal bacteria are necessary for plant-eating animals to digest A) cellulose. B) lipids. C) proteins. D) nitrogen. E) carbon dioxide.
A) cellulose.
89) In animal cells, spindle microtubules originate from structures called
A) centrioles
64) During meiosis, maternal, and paternal chromosomes can exchange genetic material at sites called
A) chiasmata.
88) Kinetochores attach
A) chromatids to spindle microtubules.
63) Prokaryotic cells do NOT have A) cilia. B) genes. C) cytoplasm. D) ribosomes. E) flagella.
A) cilia.
14) DNA from different bacteria may be combined using all of the following EXCEPT A) cloning. B) transformation. C) plasmids. D) viruses.
A) cloning.
43) A sequence of three RNA bases can function as a(n) A) codon or anticodon. B) codon only. C) gene only. D) anticodon only.
A) codon or anticodon.
54) Water moves through a plant because of the property of A) cohesion. B) high heat of vaporization. C) high specific heat. D) high heat of fusion.
A) cohesion.
35) When chromosomes become visible during prophase of mitosis, it is the result of
A) condensation.
6) Both DNA and RNA A) contain phosphate groups. B) contain the same four types of nitrogen-containing bases. C) are single-stranded molecules. D) have the same five-carbon sugars. E) cannot be present in a cell simultaneously.
A) contain phosphate groups.
40) Chiasmata (or chiasma) provide evidence of
A) crossing over.
65) Chiasmata are the locations of
A) crossing over.
61) The distribution of cytoplasm to daughter cells is accomplished during
A) cytokinesis.
64) End products of the different fermentation processes include all of the following EXCEPT
A) water.
60) A(n) ________ mutation is when one or more nucleotide pairs are lost.
A) deletion
15) In DNA, phosphate groups bond to
A) deoxyribose.
15) The carbohydrate in DNA is A) deoxyribose. B) phosphate. C) glucose. D) ribose. E) cellulose.
A) deoxyribose.
69) Adhesion of cells within animal tissues is accomplished by cell-to-cell junctions called A) desmosomes. B) tight junctions. C) gap junctions. D) plasmodesmata.
A) desmosomes.
83) Hemophilia is a genetic disease that has plagued the royal houses of Europe since the time of Queen Victoria, who was a carrier. Her granddaughter, Alexandra, married Nicholas II, the last czar of imperial Russia. Alexandra was a carrier for hemophilia, but Nicholas was normal. Their son, Alexis, was afflicted with the disease. Based on this scenario, it is most likely that
A) each of the sisters had a 50% chance of being a carrier of the gene.
1) A substance with specific properties that cannot be broken down or converted into another substance is called a(n) A) element. B) mixture. C) molecule. D) compound. E) ion.
A) element.
16) In the glucose activation stage of glycolysis, glucose receives a phosphate group from ATP. This reaction is
A) endergonic.
55) Within a cell undergoing anaerobic metabolism of glucose, fermentation occurs in the B) phospholipid bilayer of the cell membrane.
A) fluid portion of the cytoplasm.
4) Meiosis typically results in the production of
A) four haploid cells.
15) During glycolysis in the energy-investing stage, two ATP molecules are "spent" to convert glucose to the highly reactive molecule
A) fructose bisphosphate.
10) The major histocompatibility complex (MHC) is an example of a(n) A) glycoprotein. B) phospholipid. C) organelle. D) polysaccharide.
A) glycoprotein.
72) In the alternation of generations life cycle, adults may be
A) haploid or diploid.
46) A neutral solution A) has equal amounts of H+ and OH-. B) has no H+. C) has a pH of 0. D) has no OH-. E) is hydrophobic.
A) has equal amounts of H+ and OH-.
45) If a substance measures 7 on the pH scale, that substance A) has equal concentrations of H+ and OH- ions. B) is basic. C) probably lacks OH- ions. D) has a higher concentration of OH- than H+ ions. E) may be lemon juice.
A) has equal concentrations of H+ and OH- ions.
19) The results of a test cross reveal that all the offspring resemble the parent being tested. This parent must be
A) homozygous.
10) If digestion is ________, then synthesis is ________. A) hydrolysis;dehydration synthesis B) inorganic;organic C) dehydration synthesis; hydrolysis D) organic; inorganic
A) hydrolysis;dehydration synthesis
9) The phospholipids that make up the plasma membrane have ________ heads and ________ tails. A) hydrophilic; hydrophobic B) prokaryotic; eukaryotic C) hydrophobic; hydrophilic D) cytoplasmic; phagocytic E) eukaryotic; prokaryotic
A) hydrophilic; hydrophobic
14) The X-ray diffraction pattern for DNA suggested to Wilkins and Franklin all of the following features about DNA EXCEPT
A) in a DNA molecule, A pairs with T and G pairs with C.
17) For bacteria to continue growing rapidly when they shift from an aerobic environment to an anaerobic environment, they must
A) increase the rate of glycolysis.
106) All of the following play a role in the development of cancer EXCEPT
A) inhibition of Cdk and blocking of DNA replication.
15) Atoms or molecules that have gained or lost electrons are called A) ions. B) covalent. C) acids. D) bases. E) buffers.
A) ion
49) Milk of magnesia is often used to treat stomach upset. It has a pH of 10. Based on this information, milk of magnesia A) is a base. B) is hydrophobic. C) has the same pH as stomach acid. D) is an acid.
A) is a base.
26) The atomic number of hydrogen is 1. Based on this fact, all of the following must be true of hydrogen gas (H2) EXCEPT that it A) is a polar molecule. B) shares one pair of electrons between the two hydrogen atoms. C) uses covalent bonds to form the molecule. D) is a stable molecule.
A) is a polar molecule.
61) All of the following are true regarding pedigree analysis EXCEPT that it
A) is exclusively used to study the patterns of inheritance in dogs.
49) Suppose you have two glucose solutions separated by a selectively permeable membrane. If there is a concentration gradient of glucose across the membrane, then the solutions cannot be ________ relative to each other. A) isotonic B) hypotonic C) hypertonic
A) isotonic
44) Sequencing the genes of humans is important because A) knowing the nucleotide sequence of human genes will aid in the treatment of diseases caused by them. B) it will allow scientists to create human clones. C) it provides information on how to build lipids in the cell. D) it will give us a better understanding of agricultural animals.
A) knowing the nucleotide sequence of human genes will aid in the treatment of diseases caused by them.
55) Osmosis moves water from a region of A) low solute concentration of to a region of high solute concentration. B) low concentration of water to a region of high concentration of water. C) high solute concentration to a region of low solute concentration. D) negative osmotic potential to a region of positive osmotic potential. E) hypertonic solution to a region of hypotonic solution.
A) low solute concentration of to a region of high solute concentration.
17) Which of the following molecules transfers information from the nucleus to the cytoplasm? A) mRNA B) Proteins C) DNA D) tRNA E) Lipids
A) mRNA
40) The part of a mitochondrion that is analogous to the stroma of a chloroplast is the
A) matrix.
16) Mendel's law of segregation states that
A) members of a pair of alleles on homologous chromosomes move away from each other
70) What is an advantage to an organism producing microRNA? A) microRNA can protect against viral infections. B) microRNA can protect against heart disease and cancer. C) microRNA causes mutations in unused genes. D) microRNA allows for the inactivation of Barr bodies.
A) microRNA can protect against viral infections.
59) If you place a paper towel in a dish of water, the water will A) move up the towel as the water adheres to the paper towel while the cohesive water molecules stay bound to each other. B) dissolve the towel because water is a good solvent. C) separate into H+ and OH- ions, which will react with the paper towel molecules. D) move away from the towel because water molecules have hydrophobic interactions. E) move up the towel because water molecules move quickly as it vaporizes.
A) move up the towel as the water adheres to the paper towel while the cohesive water molecules stay bound to each other.
66) The failure of chromosomes to segregate properly during meiosis is called
A) nondisjunction.
3) The atomic number of an atom is defined as the A) number of protons in the atomic nucleus. B) number of neutrons in the atomic nucleus. C) total number of electrons and neutrons. D) number of electrons in the outermost energy level. E) total number of energy shells.
A) number of protons in the atomic nucleus.
6) According to the law of segregation, in an organism with the genotype Aa
A) one-half of the gametes get the A allele and one-half get the a allele.
42) The diffusion of water molecules across a selectively permeable membrane is called A) osmosis. B) hydrolysis. C) active transport. D) facilitated diffusion. E) exocytosis.
A) osmosis.
1) Bacterial cell walls contain ________, which makes them different from other organisms. A) peptidoglycan B) starch C) cellulose D) pectin E) chitin
A) peptidoglycan
102) Kinases are responsible for the addition of ________ to other proteins.
A) phosphate
26) DNA is negatively charged because of its A) phosphate groups. B) bases. C) ribose molecules. D) deoxyribose molecules. E) large molecular size.
A) phosphate groups.
67) Specialized cell junctions include all of the following EXCEPT A) phospholipases. B) tight junctions. C) gap junctions. D) desmosomes.
A) phospholipases.
76) All of the following are expected to result in genetic variation among offspring EXCEPT B
A) prokaryotic fission.
25) Ribosomes are a collection of A) proteins and small RNAs that function in translation. B) proteins and tRNAs that function in transcription. C) mRNAs and tRNAs that function in translation. D) proteins and mRNAs that function in translation. E) small proteins that function in translation.
A) proteins and small RNAs that function in translation.
21) Fibers of the cytoskeleton are composed of primarily A) proteins. B) ER. C) lipids. D) nucleic acids. E) polysaccharides.
A) proteins.
12) Keratin and silk are examples of ________, whereas glucose and maltose are examples of ________. A) proteins; carbohydrates B) carbohydrates; proteins C) nucleic acids; lipids D) proteins; lipids
A) proteins; carbohydrates
34) To join a fragment of human DNA to bacterial or yeast DNA, both the human DNA and the bacterial or yeast DNA must first be treated with the same A) restriction enzyme. B) DNA gyrase. C) DNA ligase. D) DNA polymerase.
A) restriction enzyme.
12) Sexual reproduction
A) results in new combinations of genetic traits.
14) When alleles on a pair of homologous chromosomes move into different gametes during meiosis, this demonstrates
A) segregation.
14) Sea stars are genetically different from each other and from their parents. These genetic differences are the result of .
A) sexual reproduction.
59) The gases O2 and CO2 enter or leave a plant cell by A) simple diffusion. B) osmosis. C) facilitated transport. D) facilitated diffusion. E) active transport.
A) simple diffusion.
62) If you place a feather on the surface of a bowl of water, the feather remains suspended on the surface due to the A) surface tension of the water. B) polarity of the water. C) density of the water. D) fact that water is a good solvent.
A) surface tension of the water.
4) All of the following are true statements about ATP EXCEPT that it is
A) synthesized only within mitochondria. 5) Which of the following statements is TRUE of glycolysis? E) It produces a net gain of ATP.
72) The nuclear membrane re-forms during
A) telophase.
29) Meiotic cell division in animals occurs in the ________ and results in the production of ________. A) testes and ovaries
A) testes and ovaries; gametes
35) The step in aerobic respiration that produces the most ATP per molecule of glucose is
A) the ETC.
45) The interval before the onset of DNA replication is
A) the G1 stage.
104) Cancer is essentially
A) the cell to ignore the checkpoints of the cell cycle
43) When chromosomes replicate
A) the two DNA strands separate and each is used as a template for synthesis of a new strand.
54) The rate of facilitated diffusion of a molecule across a membrane will increase as the concentration gradient of the molecule across the membrane increases to a certain point. Eventually, an increase in the concentration of the molecule will not cause any further increase in facilitated diffusion. Thus, there is a maximal rate of facilitated diffusion. This is because A) there are a limited number of carrier proteins in the membrane. B) facilitated diffusion requires ATP energy. C) the increased concentration gradient causes a situation far from equilibrium. D) the diffusion constant depends on the concentration gradient. E) as the concentration gradient increases, molecules interfere with one another.
A) there are a limited number of carrier proteins in the membrane.
23) The type of RNA that binds to a specific amino acid is A) transfer RNA. B) nuclear RNA. C) ribosomal RNA. D) messenger RNA.
A) transfer RNA
21) Yellow-seeded pea plants may be homozygous or heterozygous. To find out which, cross the plants with
A) true-breeding green-seeded plants.
64) If you forget to water your favorite plant, all of the following will occur at a cellular level EXCEPT A) turgor pressure will build up in the cell. B) water will move out of the cytosol by osmosis. C) osmosis will occur. D) the plasma membrane will shrink away from the cell wall. E) water will move out of the vacuoles by osmosis.
A) turgor pressure will build up in the cell.
54) Mutations are a source of genetic ________ by which evolutionary change is possible.
A) variability
74) Assume a genetic analysis of a sick animal's DNA indicates that part of one chromosome does not belong to the animal. It is foreign DNA and is not similar to any of the animal's normal genes. It most likely comes from a(n) A) viral infection. B) fungal infection. C) prion infection. D) bacterial infection. E) archaeal infection.
A) viral infection.
76) Different types of living matter often have different forms of the same elements in their bodies. For example, the nitrogen in an animal often has a slightly different atomic structure than the nitrogen in a plant. Recently, nutritionists have discovered how to deduce the diets of various animal species by examining the type of nitrogen (and other elements) inside their bodies. What is the chemical basis behind this scenario? A) Isotopes of the same element have the same atomic number but different atomic masses. B) Radioactive elements can be used to trace the paths of molecules through the body. C) Antioxidants buffer the potential damage that free radicals do to cells. D) Hydrophobic interactions keep water molecules from forming bonds with fats and oils. E) Covalent bonds result when two atoms share electrons.
A)Isotopes of the same element have the same atomic number but different atomic masses.
Which of the following is a correct difference between active transport and facilitated diffusion? (eText Concept 7.4) * Facilitated diffusion involves transport proteins, and active transport does not. * Active transport requires energy from ATP, and facilitated diffusion does not. * Facilitated diffusion can move solutes against a concentration gradient, and active transport cannot. * Active transport involves transport proteins, and facilitated diffusion does not. * Active transport can move solutes in either direction across a membrane, but facilitated diffusion can only move in one direction.
Active transport requires energy from ATP, and facilitated diffusion does not.
All of the following are components of the modern cell theory EXCEPT:
All cells arise from preexisting cells.
What do Alzheimer's, Parkinson's, and mad cow disease have in common?(eText Concept 5.4) * They all cause the misfolding of nucleic acids. * All are associated with the buildup of lipids in brain cells due to faulty lysosome activity. * All have been associated with the buildup of misfolded proteins in cells. * They all associated with plaque buildup in arteries (atherosclerosis). * All are caused by the buildup of misfolded proteins in cells.
All have been associated with the buildup of misfolded proteins in cells.
Which of the following is/are likely to limit the maximum size of a cell? (eText Concept 6.2) * the shape of the cell * the cell's surface-to-volume ratio * the time it takes a molecule to diffuse across a cell * All of the choices are correct. * None of the choices is correct.
All of the choices are correct.
Which statement(s) about the sidedness of the plasma membrane is/are correct? (eText Concept 7.1) * Parts of proteins that are exposed on the cytoplasmic side of the endoplasmic reticulum are also exposed on the cytoplasmic side of the plasma membrane. * The two lipid layers may differ in specific lipid composition. * Every integral membrane protein has a specific orientation in the plasma membrane. * The asymmetrical distribution of membrane proteins, lipids, and carbohydrates across the plasma membrane is determined as the membrane is being constructed. * All of the listed responses are correct.
All of the listed responses are correct.
Enzyme molecules require a specific shape to perform their catalytic function. Which of the following might alter the shape of an enzymatic protein? (eText Concept 5.4) * mixing in a chemical that removes hydrogen bonds * a change in salt concentrations or pH * heating the protein * denaturing the protein * All of the listed responses are correct.
All of the listed responses are correct. Correct. All of the listed responses would affect the shape and therefore the catalytic activity of the enzymatic protein.
Which of the following is true regarding complementary base pairing in DNA and RNA molecules? (eText Concept 5.5) * Complementary base pairing within single strands of DNA and RNA gives them particular three-dimensional structures that are necessary for their function. * Complementary base pairing promotes an antiparallel orientation in the structure of DNA and RNA molecules. * Although the base pairing between two strands of DNA in a DNA molecule can be thousands to millions of base pairs long, base pairing in an RNA molecule is limited to short stretches of nucleotides in the same molecule or between two RNA molecules. * Although a DNA molecule demonstrates complementary base pairing between two DNA polynucleotides to form a double helix, an RNA molecule can only base pair along stretches of nucleotides in the same RNA molecule, such as in transfer RNA molecules. * None of the listed responses is correct
Although the base pairing between two strands of DNA in a DNA molecule can be thousands to millions of base pairs long, base pairing in an RNA molecule is limited to short stretches of nucleotides in the same molecule or between two RNA molecules.
10) A carefully formulated scientific explanation that is based on extensive observations and is in accord with scientific principles is called a A) postulate. B) theory. C) fact. D) control. E) hypothesis.
B
12) Suppose you are testing a treatment for AIDS patients and find that 75% respond well whereas 25% show no improvement or a decline in health. You should A) conclude that you have proven the effectiveness of the drug. B) review the results modify the drug or the dosage and repeat the experiment. C) begin work on developing a new drug. D) discontinue experimentation with this treatment because 25% of patients did not improve. E) conclude that only 75% of AIDS patients should be treated.
B
18) Which of the following levels of organization is the most inclusive (i.e. includes the most life-forms)? A) Population B) Biosphere C) Species D) Community E) Ecosystem
B
19) The smallest units that still retain the characteristics of an element are called A) molecules. B) atoms. C) cells. D) tissues. E) organic molecules.
B
20) Which of the following is an example of deductive reasoning? A) Living objects are composed of cells. B) If an object exhibits all the characteristics of life it must be living. C) Atoms make up molecules which make up cells which make up tissues. D) All objects on Earth will fall down when dropped and none will "fall up."
B
23) To test the effect of vitamin D on growth two groups of rats were raised under identical conditions 2 and fed the same diet. One of the groups received daily injections of vitamin D. The other group received injections of saline which did not contain vitamin D. All the rats were weighed weekly for 2 months. In this experiment the control was the A) average weight gain of the rats. B) group receiving saline. C) 2-month period of time. D) group receiving vitamin D.
B
28) A mutation is a A) dose of radiation. B) change in the DNA sequence. C) physical deformity such as the loss of a limb. D) defective egg or sperm cell.
B
3) Science cannot answer certain faith-based questions because A) there aren't enough variables. B) faith-based beliefs are impossible to either prove or disprove. C) scientists are not able to study human behavior. D) faith requires deductive reasoning.
B
30) The concept of evolution is based on A) any type of genetic variation within a population. B) survival and successful reproduction in organisms with favorable variations. C) all genetic variation in a population being equally successful in the same environment. D) parents with variations that pass these variations on to their offspring.
B
33) The variation among individuals on which natural selection acts describes A) random occurrences in the lifetimes of individuals. B) genetic differences. C) nutritional differences. D) physical training and exercise.
B
37) Dinosaurs are not alive today because they A) evolved adaptations that were beneficial in their constant unchanging environment. B) did not evolve fast enough to keep up with rapid environmental change. C) evolved too quickly in response to a changing environment. D) did not possess the genetic material that beneficial mutations act on.
B
38) Which of the following is a characteristic of living organisms? A) Have membrane-bound organelles B) Maintenance and regulation of internal conditions C) Ability to produce energy D) Eat other organisms E) Have a nucleus
B
45) An organism in the domain Eukarya is characterized by all of the following EXCEPT 45) A) the ability to maintain precise internal conditions. B) being composed of prokaryotic cells. C) the potential to grow and reproduce. D) ingestion of organic matter to acquire nutrients.
B
48)A sunflower follows the sun as it moves across the sky during the period of a single day.
B
53) Over time, the average neck length of giraffes has increased. Only those giraffes with longer necks survived by eating the leaves high up on the trees, and they were able to reproduce and pass those long-neck genes on to the next generation.
B
7) We use the scientific method every day. Imagine that your car doesn't start one morning before A) I should change the battery or the starter. B) If I put gas in my carit will start. C) I should check whether the lights were left on and drained the battery. D) I'm going to be late. E) I should add a quart of oil.
B
72) A 57-year-old woman was admitted to a hospital with an infected toe, and the infection was 90) spreading rapidly. The damage was being caused by an unknown microorganism that could not be cultured in the lab. Doctors observed that antibiotics, which kill only prokaryotes, were ineffective. They suspected that the microbe was a fungus, so they tried the drug Amphotericin, which targets the ergosterols in fungal cells. Because animal cells contain cholesterols, not ergosterols, they are unaffected by the drug. Shortly after receiving Amphotericin, the patient improved, her infection ceased, and she was released from the hospital. In this scenario, what was the hypothesis? A) A microbe that has cholesterol is causing the infection. B) Antibiotics will not kill the microbe because it is a fungal species. C)The infection will spread rapidly. D)If the infection is caused by an animal, then Amphotericin will cure the patient. E) Why didn't the antibiotics kill the microbe that caused the infection?
B
8) A scientific theory A) is less reliable than a hypothesis. B) is a general explanation for natural phenomena. C) will never be changed. D) is an educated guess.
B
9) A scientific explanation that is conditional and requires more investigation is called a(n) A) fact. B) hypothesis. C) theory. D) observation. E) control.
B
Cells A and B are the same size, shape, and temperature, but cell A is metabolically less active than cell B; cell B is actively converting oxygen to water in cellular respiration. Oxygen will diffuse more rapidly into cell _____ because _____. (eText Concept 7.3) * B ... the oxygen molecules inside cell B have a higher kinetic energy * A ... the diffusion gradient there is shallower * B ... the gradient of oxygen is oriented in the opposite direction compared to cell A * B ... the diffusion gradient in cell B is steeper * A ... its membrane transport proteins will not be saturated
B ... the diffusion gradient in cell B is steeper
48) DNA polymerase, before any proofreading by repair enzymes, makes one mistake for about every
B) 10,000 to 1 million base pairs.
49) After proofreading repair enzymes check the work of DNA polymerase, newly replicated DNA strands contain about one mistake for every
B) 100 million to 10 billion base pairs.
52) Two parents with normal vision have two sons, one color deficient and one with normal vision. If this couple then has six daughters, can you predict what percentage of the daughters will have normal color vision?
B) 100%
84) In people, a dimpled chin is an autosomal dominant trait. Many famous celebrities, such as John Travolta and Michael and Kirk Douglas, have this condition. Assume that the wrestler and actor Hulk Hogan is homozygous for the dimpled chin, and he married a woman with a round chin. They had two children, Brooke and Nick. What is the probability that their children will show the trait?
B) 100%
73) In mitosis, if a parent cell has 16 chromosomes, each daughter cell will have how many chromosomes?
B) 16
8) If the DNA of a certain organism has guanine as 30% of its bases, then what percentage of its bases are adenine?
B) 20%
59) In the absence of oxygen, suppose a single yeast cell undergoes fermentation and uses 100 molecules of glucose. How many molecules of ATP will be generated? A) 100 C) 36 D) 400 E) 300
B) 200
57) The diploid number of chromosomes on a human skin cell is 46. What is the number of chromosomes found in a human egg cell?
B) 23
58) In Mendel's experiments, if the gene for tall (T1) plants was incompletely dominant over the gene for short (T2) plants, what would be the result of crossing two T1T2 plants?
B) 25% tall, 50% intermediate, and 25% short
44) In one strand of DNA, the nucleotide sequence is 5'-A-T-G-C-3'. The complementary sequence in the other strand must be
B) 3'-T-A-C-G-5'.
3) What is the ratio of phenotypes in the offspring produced by the cross Aa × Aa? Assume complete dominance for the trait.
B) 75% dominant:25% recessive
33) At the beginning of prophase I, a total of ________ molecules of DNA are contained in a developing human sperm cell.
B) 92
32) In a eukaryotic cell that is undergoing cell division, what will become a new chromosome?
B) A chromatid
4) What is NOT a feature of a prokaryotic cell? A) Enzymes B) A nuclear membrane C) Ribosomes D) DNA E) A plasma membrane
B) A nuclear membrane
4) Which of the following best explains the molecular complexity of living organisms? A) Each organism has its own unique set of monomers for use in constructing polymers. B) A small number of monomers can be assembled into large polymers with many different combinations/sequences. C) Although there are not many biological molecules in cells, each one has many different functions. D) Condensation reactions can create different polymers because they can combine virtually any molecules in the cell. E) The large number of different monomers allows for the construction of many polymers.
B) A small number of monomers can be assembled into large polymers with many different
71) Cyanide poisoning occurs because cyanide inhibits an enzyme in the electron transport pathway. Which of the following is the reason why cyanide poisoning becomes deadly?
B) ATP is no longer produced by chemiosmosis.
12) If the sequence of bases in a section of DNA is TAGGCTAA, what is the corresponding sequence of bases in mRNA? A) AATCGGAT B) AUCCGAUU C) CGAAUCGG D) ATCCGATT E) TAGGCTAA
B) AUCCGAUU
40) When DNA polymerase encounters thymine in the parental strand, what does it add to the growing daughter strand?
B) Adenine
1) Which type of microscope has the best resolution? A) Hooke's microscope B) An electron microscope C) A modern light microscope D) Leeuwenhoek's microscope
B) An electron microscope
55) Which of the following does NOT produce variation?
B) Asexual reproduction
31) Imagine that a newly discovered species of fish normally has three eyes (E), but the rare mutation (e) causes "diopthalmic" fish with two eyes to be born. In addition, eye color in these fish is inherited similarly to humans, with black eyes (B) being dominant to blue (b). Assuming these two genes are carried on separate chromosomes, what must the genotypes of two black-eyed, three-eyed parents be if they have a blue-eyed, diopthalmic son?
B) Both EeBb
36) Which of the following occurs in the nucleus? A) Replication of genetic material only B) Both transcription and replication of genetic material C) Transcription only D) Both translation and replication of genetic material E) Translation only
B) Both transcription and replication of genetic material
6) DNA possesses
B) C, T, A, and G bases.
21) If the DNA sequence is G-C-C-T-A-T in one polynucleotide chain, then the sequence found in the other polynucleotide chain must be
B) C-G-G-A-T-A.
2) Which of the following is NOT an organic molecule? A) Protein B) Carbon monoxide C) Monosaccharide D) Lipid E) Nucleic acid
B) Carbon monoxide
11) Which of the following are permanently differentiated cells?
B) Most brain cells
57) Two similar-sized animal cells are placed in a 0.5% sucrose solution. Cell A enlarges for a while and then stops cell B continues to enlarge and finally ruptures. Which of the following must have been TRUE at the beginning of the experiment? A) Cell A was hypertonic to the solution, and cell B was hypotonic. B) Cell B has a higher concentration of sucrose than cell A. C) Cell A was hypotonic to the solution, and cell B was hypertonic. D) Cell A has a higher concentration of sucrose than cell B. E) Cells A and B were isotonic to each other.
B) Cell B has a higher concentration of sucrose than cell A.
100) What would be a consequence of a mutation that disables the production of cyclin-dependent kinases (Cdks)?
B) Cell-cycle control would not be possible.
47) Which of the following is capable of converting solar energy into chemical energy? A) Mitochondria B) Chloroplasts C) Vesicles D) Golgi apparatus E) Vacuoles
B) Chloroplasts
69) Four of the five answers listed below are events occurring during mitosis. Select the exception.
B) Chromosome replication
25) Which of the following types of membrane proteins are responsible for maintaining cell shape by linking the membrane protein with the cytoskeleton? A) Transport proteins B) Connection proteins C) Enzymes D) Receptor proteins E) Recognition proteins
B) Connection proteins
50) What do carbohydrates, lipids, and proteins have in common? A) All are inorganic molecules. B) Covalent bonding holds these molecules together. C) All are important enzymes that function within the cell. D) Polymers of these organic molecules form monomers via dehydration synthesis reactions.
B) Covalent bonding holds these molecules together.
40) What would be TRUE if linkage of two genes was complete?
B) Crossing over between the two genes would rarely occur. 41) A human sperm cell possesses autosomes and A) either an X or a Y chromosome. 42) In humans, the sex of the offspring is determined by the C) sex chromosome carried by the sperm cell.
44) Which of the following does NOT occur in prophase I of meiosis?
B) Cytokinesis
12) Hershey and Chase concluded that ________ is the hereditary molecule by examining how radioactively labeled molecules moved between a virus and bacteria.
B) DNA
26) Which of the following contains four types of nucleotides but no uracil? A) Ribosomal RNA B) DNA C) Messenger RNA D) Transfer RNA E) RNA polymerase
B) DNA
27) Which of the following has two polynucleotide strands? A) Ribosomal RNA B) DNA C) Messenger RNA D) Transfer RNA E) RNA polymerase
B) DNA
28) Which of the following contains deoxyribose? A) Ribosomal RNA B) DNA C) Messenger RNA D) Transfer RNA E) RNA polymerase
B) DNA
7) Genetic inheritance is based on what type of molecule?
B) DNA
39) All of the following are directly involved in translation EXCEPT A) ribosomes. B) DNA. C) amino acids. D) mRNA. E) tRNA.
B) DNA.
75) Which of the following cell cycles is represented by birds?
B) Diploid life cycle
1) Which of the following is TRUE of cell division?
B) Each daughter cell receives half of the cytoplasm from the parent cell.
18) How many copies of a particular gene of interest are produced from a single template DNA strand after three cycles of PCR? A) Two B) Eight C) Five D) Three E) Four
B) Eight
32) Which of the following is a normal inhabitant of a cow's digestive tract that can cause harm to people when it contaminates ground beef? A) Borrelia burgdorferi B) Escherichia coli C) Streptococcus pneumoniae D) Clostridium tetani E) Yersinia pestis
B) Escherichia coli
51) More than half a century ago, two cell biologists published details of their research involving isolated membrane vesicles from chloroplasts. Normally, the fluid inside these vesicles is near neutral. In an experiment, these membrane vesicles were soaked in an acidic solution (pH 4) until the inside of the vesicle also became pH 4. Based on the details provided in this scenario, by what mechanism could hydrogen ions have crossed the vesicle membrane, and what do you think happened at the molecular level? A) Simple diffusion; hydrogen ions moved into the vesicle through a channel protein. B) Facilitated diffusion; hydrogen ions moved into the vesicle through a channel protein. C) Active transport; hydrogen ions moved out of the vesicle with the help of ATP energy. D) Osmosis; water moved from inside the vesicle to outside. E) Pinocytosis; water moved from outside the vesicle to inside.
B) Facilitated diffusion; hydrogen ions moved into the vesicle through a channel protein.
60) In vertebrate animal cells, where does the synthesis of lactate occur?
B) Fluid portion of the cytoplasm
53) How many total daughter cells are produced from each parent cell as a result of meiosis?
B) Four
22) Which of the following is TRUE in the Watson-Crick model of DNA?
B) Four different types of bases are found in DNA.
98) DNA replication is controlled at the ________ checkpoint.
B) G2
20) If a tRNA molecule that is specialized for the transfer of the amino acid valine has the anticodon CAG, it will couple with the codon A) GAC. B) GUC. C) TUG. D) GTC. E) CAG.
B) GUC.
49) Which of the following was successfully used to treat a patient with severe combined immunodeficiency (SCID)? A) Growth hormones B) Gene therapy C) Insulin D) Bt toxins E) Vaccines
B) Gene therapy
1) All of the following are goals of biotechnology EXCEPT A) efficiently producing biologically important molecules. B) creating humans with higher intelligence levels. C) generating economic benefits. D) treating disease more effectively. E) improving agriculturally important food plants.
B) creating humans with higher intelligence levels.
72) For years, the residents of a small Mexican town complained about the filth from a nearby hog farm, where millions of pigs are raised each year. In 2009, the majority of residents in this town became sick with "swine flu," caused by the H1N1 influenza virus. This virus infects people but is apparently genetically similar to a virus that infects hogs. The virus has since gone on to infect (and, in some cases, kill) people in Mexico City, and has quickly spread around the entire planet. The "swine flu" has been declared a global pandemic. Based on this scenario and your knowledge of genetics, what is a potential technique that could be used to prevent this disease? A) Develop a technique for STRs in swine. B) Genetically engineer flu-resistant pigs. C) Encourage people not to consume pig products. D) Make recombinant viral and human DNA.
B) Genetically engineer flu-resistant pigs.
23) In humans, dental cavities form when Streptococcus mutans bacteria in the mouth hydrolyze sucrose. Which of the following is (are) the products of this reaction? A) Glucose and galactose B) Glucose and fructose C) Starch D) Glycogen
B) Glucose and fructose
9) Which event occurs in the fluid portion of the cytoplasm of a cell undergoing glucose metabolism?
B) Glycolysis
34) Which cellular organelle packages enzymes and forms lysosomes? A) Smooth ER B) Golgi apparatus C) Rough ER D) Mitochondrion
B) Golgi apparatus
39) Researchers have been able to study the pathway of a secreted protein by "tagging" it with a fluorescent marker. Using this method, you would observe fluorescence moving from the ER to which organelle? A) Mitochondria B) Golgi apparatus C) Lysosome D) Nuclear membrane E) Plasma membrane
B) Golgi apparatus
42) Which virus attacks white blood cells? A) Smallpox B) HIV C) Herpes D) Rabies E) Influenza
B) HIV
2) Which of the following is NOT true of human chromosomes?
B) Human gametes end up with two of each type of 23 chromosomes.
68) In which of the stages below does each chromosome consist of two DNA molecules? (I. metaphase, II. telophase, III. prophase, IV. anaphase)
B) I and III
75) Sickle-cell anemia is caused by a recessive mutation in the hemoglobin gene. However, heterozygote individuals also show a small percentage of sickled red blood cells. What type of inheritance pattern is this an example of?
B) Incomplete dominance
40) Cells spend most of their time in what phase?
B) Interphase
73) Suppose a scientist working on a new drug for cancer developed a chemical that irreversibly breaks the hydrogen bonds in the DNA molecules within cancerous cells but leaves all of the covalent bonds intact. Hydrogen bonds are relatively weak compared to covalent bonds, and they are routinely broken and reformed as the DNA molecule is replicated in a normal cell. Their stability is nonetheless critical for maintaining certain aspects of the structure and function of the DNA molecule. Based on this scenario and your knowledge of DNA, how would this newly discovered chemical affect the "molecule of heredity" in a human cancer cell?
B) It would break the two strands of the DNA molecule apart, preventing it from functioning normally.
10) For an atom to achieve maximum stability and become chemically inert, what must occur? 10) A) Electron pairs are shared. B) Its outermost energy shell must be completely filled with electrons. C) Ionization occurs. D) The number of electrons must equal the number of protons.
B) Its outermost energy shell must be completely filled with electrons.
56) Which of the following is an example of a protein? A) ATP B) Keratin C) Cellulose D) Estroge
B) Keratin
14) Which molecule is a disaccharide? A) Fructose B) Lactose C) Glucose D) Water
B) Lactose
39) Imagine that you have isolated a mysterious liquid from a sample of food. You add the liquid to a beaker of water and shake vigorously. After a few minutes, the water and the other liquid separate into two layers. To which class of biological molecules does the unknown liquid most likely belong? A) Nucleic acids B) Lipids C) Enzymes D) Carbohydrates E) Proteins
B) Lipids
66) Which of the following is the densest? A) Ice B) Liquid water C) Steam
B) Liquid water
44) For which of the following diseases or conditions should antibiotics be used? A) A common cold B) Lyme disease C) Mad cow disease D) AIDS (to combat HIV) E) Smallpox
B) Lyme disease
52) Which of the following contains codons? A) RNA polymerase B) Messenger RNA C) Transfer RNA D) Ribosomal RNA E) DNA
B) Messenger RNA
25) What does H-O-H represent? A) Atom of water B) Molecule of water C) Ionic bonding of water D) Mixture including water
B) Molecule of water
34) What is active transport? A) Diffusion of molecules within a cell B) Movement of molecules into or out of a cell against a concentration gradient C) Movement of molecules into or out of a cell using special proteins and not requiring an expenditure of energy D) Rapid movement of molecules in a solution E) Movement of molecules into or out of a cell down a concentration gradient
B) Movement of molecules into or out of a cell against a concentration gradient
58) What is the significance of the conversion of pyruvate to lactate during fermentation?
B) NAD+ is regenerated for use in glycolysis.
26) Which component of a DNA nucleotide could be removed without breaking the polynucleotide chain?
B) Nitrogen base
28) Which of the following is insoluble in water? A) Sucrose B) Olive oil C) Amino acids D) Salt E) DNA
B) Olive oil
15) Which of the following is NOT a natural means of DNA recombination? A) Viral infection B) PCR C) Transformation in bacteria D) Sexual reproduction
B) PCR
5) Which of the following is the correct structure of a nucleotide?
B) Phosphate-sugar-base
27) Which type of lipid is most important in biological membranes? A) Fat B) Phospholipid C) Oil D) Steroid E) Wax
B) Phospholipid
40) Which of the following results from an unequal sharing of electrons between atoms? A) Nonpolar covalent bond B) Polar covalent bond C) Ionic bond D) Hydrogen bond E) Electron-proton interaction
B) Polar covalent bond
54) Which of the following is a valid scientific concern about the environment and transgenic crops? A) Eating transgenic foods will permanently change human DNA. B) Pollen from transgenic crops could carry the recombinant genes to wild relatives, with unpredictable consequences. C) Wild animals might eat the transgenic crops and become genetically mutated. D) The toxic products of the modified genes would be released to the environment when the plants die, resulting in drastic die-offs of local wildlife.
B) Pollen from transgenic crops could carry the recombinant genes to wild relatives, with unpredictable consequences.
65) Scientists consider prions to be "puzzling" proteins. Which of the following is TRUE about prions? A) Prions are proteins that are denatured more easily than most proteins. B) Prions are proteins that cause nearby proteins to change shape and become infectious. C) Prions are infectious proteins that cannot be denatured by any amount of heat. D) Prions are noninfectious proteins.
B) Prions are proteins that cause nearby proteins to change shape and become infectious.
80) During which phase of mitosis do chromosomes condense?
B) Prophase
82) Which phase of mitosis is a "preparatory" step involving the development of spindle microtubules?
B) Prophase
78) Which of the following is the correct sequence of stages in mitotic cell division?
B) Prophase → metaphase → anaphase → telophase
66) Which of the following correctly matches an organic polymer with its monomers, respectively? A) Lipid; steroids B) Protein;amino acids C) Hydrocarbon; monosaccharides D) DNA; ATP E) Carbohydrate; polysaccharides
B) Protein;amino acids
13) What type of allele produces its effects in only homozygous individuals?
B) Recessive
15) Round pea shape (R) is dominant over wrinkled pea shape (r). If a round pea has a wrinkled parent, the round pea is
B) Rr.
50) At what phase in the cell cycle does DNA replication occur?
B) S
67) Chromatids that are attached at the centromere are called what kind of chromatids?
B) Sister
8) Copies of chromosomes linked together at their centromeres at the beginning of meiosis are appropriately called what kind of chromatids? A) Mother r C) Homologous D) Daughter
B) Sister
56) Makes steroid hormones
B) Smooth endoplasmic reticulum
7) If the quantities of the four bases in a DNA molecule are measured, we find that
B) T = A and C = G.
46) The term chemiosmosis is associated with which process?
B) The ETC
54) Which of the following processes requires oxygen?
B) The ETC
48) Which of the following processes involves citric acid? A) The ETC
B) The Krebs cycle
47) During which phase of the eukaryotic cell cycle does DNA and chromosome replication occur?
B) The S phase of interphase
25) If the DNA fingerprint of a suspect does NOT match a blood sample from a crime scene, what can you conclude? A) The suspect may have been at the crime scene, because DNA fingerprinting has a large error rate. B) The blood sample had to come from another person, but the suspect may still have been there. C) The suspect was never at the crime scene. D) The DNA in the blood sample probably degraded in a short period of time.
B) The blood sample had to come from another person, but the suspect may still have been there.
62) How do fatigued human muscle cells repay an "oxygen debt"?
B) The cells convert lactate back to pyruvate.
43) If red blood cells are taken from the body and placed in a hypertonic solution, what happens to the cells? A) They become white blood cells. B) The cells shrivel up because water leaves them. C) The cells swell and burst because water moves into them. D) The cells remain unchanged due to equal water concentrations inside and outside the cells. E) The cells remain unchanged due to equal solute concentrations inside and outside the cells.
B) The cells shrivel up because water leaves them.
67) How can a single gene code for more than one protein? A) Different RNA polymerases transcribe it and produce different proteins. B) The exons within an mRNA can be spliced together in different ways. C) Different amino acid chains can be coded by the same mRNA. D) Different types of ribosomes translate the resulting mRNA, producing different proteins.
B) The exons within an mRNA can be spliced together in different ways.
7) Which of the following accounts for the fluid aspect of the fluid mosaic model of plasma membranes? A) The plasma membrane is "fluid" because of the movement of substances across the membrane. B) The individual phospholipid molecules are not bonded to one another, so the movement of certain proteins and lipids is possible within and through the bilayer. C) One of the components of the membrane is water. D) The bilayer permits diffusion of certain lipid-soluble substances. E) The membrane is water soluble.
B) The individual phospholipid molecules are not bonded to one another, so the movement of certain proteins and lipids is possible within and through the bilayer.
15) Which of the following statements is FALSE?
B) The more highly evolved a species is, the more chromosomes it possesses.
64) You drop a handful of common table salt into a glass of water. Which of the following best describes what is happening inside the glass at the molecular level? A) Water and sodium form a covalent bond. B) The positively charged hydrogen ends of the water molecules are attracted to chloride ions. C) The positively charged hydrogen ends of the water molecules are attracted to sodium ions. D) Sodium and chloride ions form a covalent bond.
B) The positively charged hydrogen ends of the water molecules are attracted to chloride ions.
68) The ribosomes in eukaryotic cells are larger than the ribosomes in prokaryotic cells. Furthermore, eukaryotic ribosomes are not affected by some chemicals that affect prokaryotic ribosomes, a fact that can be put to good use by microbiologists seeking new antimicrobial drugs. An example of this is the antibiotic erythromycin, which prevents protein synthesis by prokaryotic ribosomes but does not affect eukaryotic ribosomes at all. Thus, erythromycin kills bacteria but does not affect humans or other animals. Using this information, which of the following would be expected and would support the endosymbiont hypothesis? A) Mitochondria and chloroplasts will not have ribosomes. B) The ribosomes in chloroplasts will be sensitive to erythromycin. C) Mitochondrial ribosomes will be smaller than prokaryotic ribosomes. D) Mitochondrial ribosomes will be larger than prokaryotic ribosomes.
B) The ribosomes in chloroplasts will be sensitive to erythromycin.
4) Phospholipids spontaneously form a bilayer in an aqueous solution. Why do the heads of the phospholipids point out and the tails point toward one another? A) The heads are repelled by the water inside and outside the cell. B) The tails are repelled by the aqueous environment, and the heads will directly interact with the aqueous solution. C) The tails are nonpolar and fohe tails are repelled by the aqueous environment, and the heads will directly interact with the aqueous solution. C) The tails are nonpolar and form hydrogen bonds with one another.
B) The tails are repelled by the aqueous environment, and the heads will directly intera
50) Which of the following is TRUE regarding how the DNA in your body's cells can accumulate mutations?
B) The ultraviolet radiation in sunlight may induce changes in DNA.
2) Which of the following statements about stem cells is TRUE?
B) They are able to differentiate into a variety of cell types.
37) Which of the following is TRUE of genes that are physically located close to each other on the same chromosome?
B) They are linked and tend to be inherited together.
33) What property of phospholipids makes them important in cell membranes? A) They contain nucleic acids. B) They have a polar end and a nonpolar end. C) They are an important energy carrier molecule. D) They are part of DNA. E) They are found only in animals.
B) They have a polar end and a nonpolar end.
21) What is an anticodon? A) Three consecutive amino acids in a protein B) Three consecutive bases in tRNA C) Four consecutive bases in tRNA D) Three consecutive bases in mRNA E) The beginning of a DNA molecule
B) Three consecutive bases in tRNA
45) What molecule is responsible for translation of the four-letter "nucleic acid language" (A, T, G, and C nucleotides) into the 20 "amino acid language" of proteins by bringing in amino acids to the ribosome? A) Ribosomal RNA B) Transfer RNA C) DNA D) Messenger RNA
B) Transfer RNA
23) In the comparison of a DNA molecule to a twisted ladder, the upright sides of the ladder are
B) deoxyribose linked to phosphate.
41) Which of the following is NOT alive? A) Cyanobacterium B) Virus C) Plant D) Bacterium E) Protist
B) Virus
29) The bacterium Vibrio cholerae releases a toxin that blocks a channel protein in the membranes of cells that line the intestine. This toxin prevents the movement of sodium ions from the inside of the intestine into cells. If the sodium ions could not move into the cells, how would this affect the movement of water between the inside of the intestine and the cells? A) Water would leave the intestines and enter the cells by facilitated diffusion. B) Water would leave the cells and enter the intestines by osmosis. C) Water would leave the intestines and enter the cells by osmosis. D) The movement of water would not be affected. E) Water would leave the cells and enter the intestines by facilitated diffusion.
B) Water would leave the cells and enter the intestines by osmosis.
11) Dental plaque is an example of A) bacterial flagella. B) a biofilm. C) an endospore. D) beneficial bacteria. E) a cell membrane.
B) a biofilm.
74) In plant cytokinesis, cellulose is laid down forming
B) a cell plate.
20) In a DNA molecule, base pairing occurs between
B) adenine and thymine.
43) If a child more strongly resembles one parent's physical traits than the other parent's, the explanation could be due to chromosome movements during
B) anaphase I.
22) We breathe more heavily during exercise because our cells
B) are producing more CO2 and need to get rid of it.
31) In recombinant DNA technology, plasmids A) show restriction enzymes where to cut bacterial DNA. B) are used to insert foreign DNA into bacteria. C) are the sites of protein synthesis in bacteria. D) are necessary for cellular respiration in certain plants. E) are isolated from the blood of mammals.
B) are used to insert foreign DNA into bacteria.
4) The history of biotechnology spans A) around 100 to 150 years. B) at least 10,000 years. C) fewer than 50 years. D) about 1,000 years.
B) at least 10,000 years.
27) The causative agents of bubonic plague, which killed 100 million people during the 14th century, were A) viruses. B) bacteria. C) fleas. D) rats. E) fish.
B) bacteria.
36) Viruses that attack prokaryotes are called A) host cells. B) bacteriophages. C) viroids. D) human pathogens. E) prions.
B) bacteriophages.
38) DNA replication occurs
B) between the gap phases (G1 and G2) of interphase.
10) The genetic recombination of ________ caused massive, widespread epidemics that affected the global human population several times in the twentieth century. A) human and bacterial plasmids B) bird flu viruses and human flu viruses C) HIV and flu viruses D) bacterial and viral plasmids
B) bird flu viruses and human flu viruses
44) All of the following are characteristics of mitochondria and chloroplasts EXCEPT A) both likely evolved from prokaryotic bacteria. B) both can capture the energy of sunlight. C) both are surrounded by a double membrane. D) both possess their own DNA, independent of the nucleus. E) both synthesize ATP.
B) both can capture the energy of sunlight.
11) Hydrolysis may be correctly described as the A) constant removal of hydrogen atoms from a carbohydrate. B) breaking of a compound into its subunits by using water to break the bond between monomers. C) removal of water from a polymer. D) heating of a compound in order to drive off its excess water and to concentrate its volume.
B) breaking of a compound into its subunits by using water to break the bond between monomers.
48) The human body must maintain a constant pH. In the blood, bicarbonate serves as a(n) ________ to help maintain the necessary pH. A) base B) buffer C) solvent D) acid
B) buffer
56) The spindle fibers are produced by the
B) centrioles
26) Replication of the bacterial ________ is required before the bacterial cell can be duplicated.
B) chromosome
8) The cytoplasm of eukaryotic cells contains all of the following EXCEPT A) organelles. B) chromosomes. C) enzymes. D) water. E) dissolved nutrients.
B) chromosomes.
46) A tRNA that carries a specific amino acid enters the protein-synthesizing machinery at the ribosomes and pairs with the appropriate A) anticodon. B) codon. C) charge. D) amino acid.
B) codon
16) Recognition proteins are most important for A) maintaining membrane integrity. B) distinguishing foreign cells from "self" cells. C) active transport of molecules. D) facilitated diffusion of molecules. E) maintaining membrane fluidity.
B) distinguishing foreign cells from "self" cells.
41) Molecules assisted by carrier proteins may cross a selectively permeable membrane by A) osmosis. B) facilitated diffusion. C) simple diffusion. D) active transport. E) endocytosis.
B) facilitated diffusion.
51) A cell from a wheat plant contains all of the following EXCEPT a A) chloroplast. B) flagellum. C) cell wall. D) mitochondrion. E) cytoskeleton.
B) flagellum.
56) For a mutation to affect the evolution of an animal species, it must occur within A) diploid cells. B) gametes. C) somatic cells. D) prokaryotic cells.
B) gametes.
56) Specific segments of DNA that code for a specific protein are called
B) genes.
4) If the allele for inflated pea pods (I) is dominant to the allele for constricted pods (i), then the cross Ii xii is expected to produce
B) half with inflated and half with constricted pods.
54) Complex, three-dimensional, tertiary structures of proteins result from A) ionic and hydrogen bonds B) hydrogen and disulfide bonds. C) disulfide bonds. D) hydrogen bonds. E) ionic bonds.
B) hydrogen and disulfide bonds.
40) Cell membranes are an example of a lipid bilayer. In this lipid bilayer, both the outside of the cell and the inside of the cell are ________ in nature. A) hydrophilic B) hydrophobic C) watery D) polar E) charged
B) hydrophobic
43) The chromosomes and genes are actually replicated during
B) interphase.
45) Anaphase
B) is initiated when the newly divided centromeres begin to move apart.
95) What are enzymes called that control the activities of other proteins by phosphorylating them?
B) kinases
87) The protein-containing structure on the centromere where microtubules attach is called the
B) kinetochore
35) Although the law of independent assortment is generally applicable, when two loci are located physically close to each other on the same chromosome, the phenotypes of the offspring sometimes do not fit the phenotypes predicted. This is due to
B) linkage.
49) Color deficiency is more common in men than in women because
B) men have only one X chromosome. 50) An individual who is a carrier for a sex-linked trait such as hemophilia C) is always female.
46) Paired homologous chromosomes are found at the
B) metaphase I.
52) The two main stages of the cell cycle are called
B) mitosis and interphase.
49) When oxygen is present
B) most animal cells utilize aerobic cellular respiration.
22) Legumes obtain a useful form of ________ from bacteria that live in root nodules. A) oxygen B) nitrogen C) hydrogen D) sulfur E) carbon
B) nitrogen
5) When Griffith experimented with two types of Streptococcus pneumoniae, he found that if the
B) non-deadly strain was mixed with the heat-killed, deadly strain before injection, the mice died.
51) Imagine that a DNA sequence of 5'-A-C-G-T-A-C-G-T-3' is altered to 5'-A-C-G-C-A-C-G-T-3'. This could happen as a result of a(n) A) inversion. C) translocation. D) insertion mutation. E) deletion mutation.
B) nucleotide substitution mutation.
70) Adenosine triphosphate (ATP) is an example of a(n) A) protein. B) nucleotide. C) inorganic molecule. D) carbohydrate. E) lipid.
B) nucleotide.
29) Disease-causing bacteria are called A) archaea. B) pathogens. C) cyanobacteria. D) viroids. E) protozoa.
B) pathogens.
34) Regarding the structure of DNA, the units that form the "uprights" (sides) of the DNA ladder and do not attach to the nitrogen bases are
B) phosphate molecules.
71) A nucleotide is made of a A) phospholipid, sugar, and nitrogenous base. B) phosphate, sugar, and nitrogenous base. C) phosphate, protein, and nitrogenous base. D) phospholipid, sugar, and protein.
B) phosphate, sugar, and nitrogenous base.
16) Plastids are found in ________ cells. A) fungal B) plant C) bacterial D) animal
B) plant
7) An organism that contains altered genes is considered all of the following EXCEPT A) genetically engineered. B) polymorphic. C) a genetically modified organism (GMO). D) transgenic.
B) polymorphic.
18) Chitin is an example of a A) monomer. B) polysaccharide. C) triglyceride. D) nucleic acid. E) peptide.
B) polysaccharide.
48) Bovine spongiform encephalopathy, or mad cow disease, is caused by a A) bacterium. B) prion. C) virus. D) viroid. E) fungus.
B) prion.
49) Creutzfeldt-Jakob disease is caused by a A) bacterium. B) prion. C) virus. D) viroid. E) fungus.
B) prion.
17) A bacterial cell splits into two new cells by a process called
B) prokaryotic fission.
31) A transcription start signal is called a(n) A) nonsense codon. B) promoter. C) initiation codon. D) start site. E) origin.
B) promoter.
11) An atom's nucleus is composed of A) protons only. B) protons and neutrons. C) protons and electrons. D) neutrons and electrons. E) neutrons only.
B) protons and neutrons.
58) Both prokaryotic and eukaryotic cells possess A) chloroplasts. B) ribosomes. C) mitochondria. D) a nucleus.
B) ribosomes.
66) In a haploid daughter cell produced by meiosis, the homologous chromosomes have
B) separated.
28) The way DNA stores information is through the ________ of bases. A) number C) size D) different types
B) sequence
19) Free radicals are considered dangerous because they A) attack the atomic nucleus. B) steal electrons from other atoms, causing those atoms to become unstable. C) damage oxygen and cause it to become an antioxidant. D) emit dangerous radiation.
B) steal electrons from other atoms, causing those atoms to become unstable.
15) A mutant plant cell with no chloroplasts would A) still be able to capture energy as sunlight. B) still be able to use carbohydrates as an energy source for a short period of time. C) appear green in color. D) synthesize new chloroplasts in the nucleus.
B) still be able to use carbohydrates as an energy source for a short period of time.
65) Your friend does a belly flop into a swimming pool. The stinging pain he feels is most likely due to the A) pH of the water. B) surface tension of water (caused by the large number of hydrogen bonds that form between water molecules). C) hydrophobic nature of your friend's skin. D) fact that water is a good solvent.
B) surface tension of water (caused by the large number of hydrogen bonds that form between water molecules).
9) The repeating sequence of cells dividing, growing, and dividing again is called
B) the cell cycle.
11) Through meiosis A) alternate forms of genes are shuffled. C) offspring are provided with new gene combinations. D) parental DNA is divided and distributed to forming gametes. E) All of the choices are correct.
B) the diploid chromosome number is reduced to haploid.
70) The urinary bladder is protected from leaking by cell-to-cell junctions called A) desmosomes. B) tight junctions. C) gap junctions. D) plasmodesmata.
B) tight junctions.
16) The process of copying genetic information from DNA to RNA is called A) translation. B) transcription. C) replication. D) transformation.
B) transcription.
6) An organism that contains foreign DNA, which was inserted into its own genetic material, is called A) electrophoresed. B) transgenic. C) polygenic. D) foreign.
B) transgenic.
14) The end product of glycolysis is
B) two pyruvate molecules.
3) You are telling your friend that organic molecules are all made up of carbon backbones with hydrogens. She doesn't understand how there can be so many different organic molecules if they all are made up of the same basic components. You explain that organic molecules A) vary because they possess different isotopes of carbon. B) vary because they possess different functional groups. C) are different because of the different types of hydrogen bonds that form. D) actually all have the same structure but differ in the number of electrons.
B) vary because they possess different functional groups.
37) Short, circular strands of RNA that can cause plant diseases are called A) bacteria. B) viroids. C) archaea. D) prions. E) viruses.
B) viroids.
5) Large biological molecules are synthesized by removing A) covalent bonds. B) water. C) peptides. D) oxygen. E) carbon.
B) water.
Imagine that beaker A has a 10% sucrose solution, and beaker B has an 8% sucrose solution. This means that:
Beaker A is hypertonic relative to beaker B.
f a red blood cell and a plant cell were placed in seawater, what would happen to the two types of cells? (eText Concept 7.3) * The red blood cell would burst, and the plant cell would shrink. * Both cells would lose water; the red blood cell would shrivel, and the plant plasma membrane would pull away from the cell wall. * Seawater is isotonic to both cells, therefore, neither cell will change as there will be no movement of water into or out of the cells. * The red blood cell would shrink, and the plant cell would gain water. * Both cells would gain water by osmosis; the red blood cell would burst, and the plant cell would increase in turgor pressure.
Both cells would lose water; the red blood cell would shrivel, and the plant plasma membrane would pull away from the cell wall. Correct. Seawater is hypertonic to both cells and will cause the cells to lose wat
Which of the following correctly compares the extracellular matrix (ECM) of animal cells to cell walls of plant cells? (eText Concept 6.7) * The structures that are external to the plasma membrane are essentially independent of the plasma membrane in both groups. * Both the ECM and the plant cell wall are composed of varying mixtures of proteins and carbohydrates. * Cell walls and ECMs provide for tight contact between adjacent cells. * The ECM and plant cell walls completely cover the plasma membrane of their respective cells. * Both the ECM and plant cell walls provide rigid structures that determine the shape of their respective cells.
Both the ECM and the plant cell wall are composed of varying mixtures of proteins and carbohydrates.
11) All of the following are features of the scientific method EXCEPT A) repeatable by other scientists. B) hypothesis formulation. C) supernatural causes. D) observation and experimentation. E) deductive reasoning.
C
13) Alexander Fleming observed a colony of mold that inhibited the growth of nearby bacteria. What was the hypothesis proposed by Fleming to explain this result? A) The mold was dead. B) The mold used all of the nutrients so that the bacteria couldn't grow. C) The mold produced a substance that killed nearby bacteria. D) The bacteria changed their DNA when growing near the mold.
C
2) Which of the following is an example of a natural cause? A) Maggots appear spontaneously on rotting meat. B) If you sneeze you will die. C) Epilepsy is a disease caused by uncontrolled firing of nerve cells in the brain. D) Mice arise from discarded garbage.
C
21) The experiments of Francesco Redi A) disproved the scientific method. B) used the scientific method to prove the idea of spontaneous generation. C) disproved the idea of spontaneous generation. D) disproved that maggots and flies were related. E) determined that fly larvae were present in raw meat and when left on the counter they turned into flies.
C
22) Francesco Redi designed an experiment to test the notion of spontaneous generation. He left the first jar of meat open to the air and covered the second jar. The first jar would be called the ________ jar. A) experimental B) hypothetical C) control D) conclusive
C
26) Which is NOT an example of evolution? A) Annual changes in the flu virus due to mutations B) The 2- to 3-year effectiveness of most commercial pesticides in killing insects C) A dog learning how to open the cabinet where its food is kept D) Flightless birds living on islands without predators E) The development of antibiotic-resistant bacteria
C
27) A mutation can be the cause for A) sexual reproduction. B) sperm and egg formation. C) natural selection. D) growth and development. E) environmental change.
C
32) Suppose an organism has an enzyme that repairs changes in its DNA. The result is a decrease in mutations. This trait would definitely influence the organism's ability to A) move. B) obtain energy. C) evolve. D) maintain homeostasis.
C
35) A change in the genetic makeup of a species over time is called A) natural causality. B) mutation. C) evolution. D) adaptation.
C
40) After you drink a glass of acidic lemonade your body's pH does not change. This is an example of how humans and other organisms A) are immune to weak acids. B) maintain cellular organization. C) maintain precise internal conditions through homeostasis. D) evolve in response to the environment.
C
43) You observe a plant on your windowsill that is growing at an angle toward the outside. This is an example of a living thing A) reproducing. B) evolving. C) responding to stimuli. D) maintaining precise internal conditions.
C
47) The main difference between an autotroph and a heterotroph is A) how they respond to stimuli. B) their ability to move. C) how they obtain energy. D) how they reproduce.
C
51) A paramecium moves from direct light toward the dark.
C
58) Which of the following statements about the Bacteria and Eukarya domains is TRUE? A) Only members of Eukarya have the ability to grow and reproduce. B) All members of Bacteria are single-celled and all members of Eukarya are multicellular. C) All members of Bacteria are prokaryotic cells and all members of Eukarya are eukaryotic cells. D) All members of Bacteria acquire nutrients via ingestion and all members of Eukarya acquire nutrients by photosynthesis.
C
59) Which group has prokaryotic individuals? 59) A) Kingdom Plantae B) Kingdom Fungi C) Domain Archaea D) Protist kingdoms E) Kingdom Animalia
C
60) Which kingdom possesses unicellular animal-like species and unicellular plantlike species? A) Fungi B) Plantae C) Protista D) Animalia
C
27) In garden peas, the allele for tall plants is dominant over the allele for short plants. Imagine that a true-breeding tall plant is crossed with a short plant. Then one of their offspring is test crossed. Out of 20 offspring resulting from the test cross, about how many should be tall?
C) 10
22) In a test cross, what percentage of the offspring will have the same phenotype as the tested parent if the parent to be tested is homozygous?
C) 100%
48) The slowest rate of diffusion of dye particles in water will occur at A) 60°C. B) 20°C. C) 10°C. D) 30°C.
C) 10°C.
32) Which of the following pairs has the most similar chemical properties to each other? 32) A) 12C and 28Si B) 1H and 22Na C) 12C and 14C D) 16O and 32S E) 1H and 2He
C) 12C and 14C
8) Which of the following statements about genotypes and phenotypes is TRUE?
C) Individuals with the same phenotype might have different genotypes.
74) Bacterial cells have only one DNA molecule, which is double stranded and is replicated in essentially the same fashion as in eukaryotes. Imagine that, following the techniques of other scientists studying DNA, you created a bacterial cell that contains only radioactive nitrogen in its DNA. You then place the cell in a culture medium containing only "regular" (nonradioactive) nitrogen. Based on this scenario and your knowledge of DNA structure and replication, how many cells will contain some DNA with radioactive nitrogen after four rounds of cell replication?
C) 2
58) A cell with 10 chromosomes undergoes mitosis and cell division. How many daughter cells are produced, and what number of chromosomes do they have?
C) 2 daughter cells
13) The oldest endospores to be revived and cultured to produce live bacteria are A) 250,000 years old. B) 25,000 years old. C) 250 million years old. D) 2,500 years old. E) 250 years old.
C) 250 million years old.
69) How many hydrogen bonds exist between a G-C base pair? A) 1 B) 2 C) 3 D) 4
C) 3
54) How many total haploid cells are produced by one diploid cell during meiosis?
C) 4
26) In a typical human body (somatic) cell, how many total chromosomes are there?
C) 46
28) In crossing a homozygous recessive with a heterozygote, what is the chance of getting a homozygous recessive phenotype in the F1 generation?
C) 50%
26) Albinism results from a recessive allele. Which of the following describes the expected offspring from a normally pigmented male (who had an albino father) and an albino wife?
C) 50% normal
9) If a bacterial protein is made from 30 amino acids, how many nucleotides are needed to code for its production? A) 30 B) 60 C) 90 D) 600 E) 120
C) 90
58) Which point mutation would be most likely to have a catastrophic effect? A) The deletion of three bases near the start of the coding sequence B) A base substitution C) A base deletion near the start of the coding sequence D) A base insertion near the end of the coding sequence E) A base deletion near the end of the coding sequence
C) A base deletion near the start of the coding sequenceC) A base deletion near the start of the coding sequence
17) "Chargaff's rule" for base pairing in DNA is that
C) A bonds with T, and G bonds with C.
76) Cystic fibrosis is a genetic disease that leads to the production of excessive, thick mucus in the respiratory tract, causing frequent and serious respiratory infections. The defect is due to the production of a faulty membrane protein for the transport of the chloride ion. The protein exists in membranes, but it doesn't function normally. Based on this scenario, what is occurring at the molecular level in a person with cystic fibrosis? A) Protein filaments in the cytoplasm are being adversely affected. B) A receptor protein is being adversely affected. C) A channel protein is being adversely affected. D) A carrier protein is being adversely affected. E) A recognition protein is being adversely affected.
C) A channel protein is being adversely affected.
67) Treponema pallidum is the organism that causes syphilis, a sexually transmitted disease. This organism moves around freely, making it well adapted to traveling within bodily fluids and being spread from host to host during intimate contact. It possesses a single chromosome and has relatively few genes. The overall shape of this single-celled organism is similar to a corkscrew, with many twists and turns along its length. Based on this information, Treponema is most likely what type of cell? A) A prokaryotic coccus B) A ciliated eukaryote C) A prokaryotic spirillum D) A flagellated eukaryote E) A prokaryotic bacillus
C) A prokaryotic spirillum
35) Which of the following causes AIDS (acquired immune deficiency syndrome)? A) A viroid B) A prion C) A virus D) A bacterium E) An archaea
C) A virus
7) Iron is an important element in human body cells. If iron has an atomic number of 26, what does 7) this tell you about this element? A) An iron atom is unable to become an isotope. B) An iron atom has 13 protons and 13 neutrons. C) An iron atom has 26 protons. D) An iron atom has 13 electrons and 13 protons.
C) An iron atom has 26 protons.
29) Which of the following is the longest?
C) An uncondensed eukaryotic chromosome
57) A contractile ring forms in which type of cells?
C) Animal
47) If you want to develop a procedure for identifying a genetic disorder caused by 20 different alleles, what method is most likely to be useful? A) STRs B) Gene therapy C) Arrays of DNA probes on filter paper D) PCR
C) Arrays of DNA probes on filter paper
57) Imagine that smurfs live in widely separated groups and rarely interbreed, so geneticists know very little about them. On one occasion, two smurfs from different groups did mate. A big-footed, white smurf mated with a small-footed, blue smurf. Three offspring resulted: one big-footed and blue and two small-footed and blue. Which statement about the inheritance of color in smurfs is most likely to be correct?
C) Blue is dominant to white.
39) If you cut out a gene using the restriction enzymes EcoRI and BamHI, what enzyme(s) will you need to insert the gene into another chromosome? A) EcoRI only B) BamHI only C) Both EcoRI and BamHI D) Neither of these enzymes
C) Both EcoRI and BamHI
61) How does one account for the bubbles in a glass of beer or champagne?
C) Bubbles of CO2 were produced by yeast during anaerobic metabolism and were trapped in the bottle.
92) During plant cell cytokinesis, what is the name of the structure that forms between the daughter cell nuclei and eventually will become the new cell wall?
C) Cell plate
22) Which of the following would NOT be found in a membrane? A) Receptor protein B) Cholesterol C) Cellulose D) Channel protein E) Phospholipid
C) Cellulose
60) Which of the following cell structures is NOT found in a bacterial cell? A) Ribosomes B) DNA C) Central vacuole D) Plasma membrane E) Cell wall
C) Central vacuole
16) Through which process are bacteria able to exchange genetic material? A) Anaerobic respiration B) Endospore formation C) Conjugation D) Photosynthesis E) Sexual reproduction
C) Conjugation
30) Regarding the structure of DNA, which of the following joins deoxyribose to phosphate?
C) Covalent bonds
4) In Griffith's experiments, what happened when heat-killed S-strain bacteria were injected into a mouse along with live R-strain bacteria?
C) DNA from the heat-killed S-strain was taken up by the live R-strain, converting them to S-strain and killing the mouse.
45) Which of the following is NOT involved in the DNA replication process?
C) DNA replicase
26) Choose the correct pathway of information flow in the cell. A) ER → DNA → RNA → protein B) ER → DNA → Golgi → protein C) DNA → RNA → protein D) RNA → DNA → protein
C) DNA → RNA → protein
23) What is the genotype of a dominant individual if, when selfed, some of its offspring show the recessive phenotype?
C) Dd
64) Which of the following is the most common chromosome disorder among live-born infants?
C) Down syndrome
36) How many different kinds of nucleotides are in DNA?
C) Four
12) What molecule is common to both C3 photosynthesis and the process of glycolysis?
C) G3P
6) Which of the following statements is FALSE?
C) Genes and chromosomes are duplicated during prophase.
52) Which of the following is a valid difference between traditional (selective breeding) and modern (genetic engineering) forms of biotechnology? A) Genetic engineering can alter the DNA sequence of entire populations, whereas selective breeding cannot. B) Selective breeding can be done much more quickly than can genetic engineering. C) Genetic engineering can use genes from unrelated species, whereas selective breeding must use genes from the same or very closely related individuals.
C) Genetic engineering can use genes from unrelated species, whereas selective breeding must use genes from the same or very closely related individuals.
53) What two bases in the DNA molecule are double-ringed? A) Guanine and cytosine B) Uracil and guanine D) Thymine and uracil E) Thymine and cytosine
C) Guanine and adenine
19) Which of the following is the correct sequence of PCR? A) Heat to 90°C (to bind primers and enzymes), then cool to 50°C (to separate DNA), and then reheat to 70°C (to synthesize DNA). B) Heat to 70°C (to separate DNA), then cool to 50°C (to bind primers and enzymes), and then reheat to 90°C (to synthesize DNA). C) Heat to 90°C (to separate DNA), then cool to 50°C (to bind primers and enzymes), and then reheat to 70°C (to synthesize DNA). D) Heat to 70°C (to bind primers and enzymes), then cool to 50°C (to synthesize DNA), and then reheat to 90°C (to separate DNA).
C) Heat to 90°C (to separate DNA), then cool to 50°C (to bind primers and enzymes), and then
58) What determines the cohesiveness of water molecules? A) Hydrophobic interactions B) Covalent bonds C) Hydrogen bonds D) Ionic bonds
C) Hydrogen bonds
6) What type of chemical reaction results in the breakdown of organic polymers into their respective subunits? A) Ionization B) Condensation C) Hydrolysis D) Oxidation
C) Hydrolysis
39) Which of the following results from a transfer of electron(s) between atoms (e.g., NaCl)? A) Nonpolar covalent bond B) Polar covalent bond C) Ionic bond D) Hydrogen bond E) Electron-proton interaction
C) Ionic bond
50) What is meant by the statement that water has a high specific heat? A) Water freezes easily. B) Water can heat up to only a certain temperature. C) It can absorb a lot of energy without changing temperature. D) The boiling point of water is low. E) It grows hot quickly.
C) It can absorb a lot of energy without changing temperature.
69) Bacteria in our mouths feed off the sugars in foods that we eat. As these bacteria ferment the sugars, they generate a product that can cause dental cavities. What is this product?
C) Lactic acid
34) Lard is a solid fat at room temperature. What does this tell you about the triglycerides in lard? A) Lard is composed of unsaturated fats. B) The fats in lard are not organic molecules. C) Lard is composed of saturated fats. D) The fats in lard are mostly phospholipids.
C) Lard is composed of saturated fats.
37) What is an advantage to a farmer using an insect-resistant crop plant? A) More herbicide use but less pesticide use B) Sterile plants, with inability to form strange hybrids C) Less pesticide use and better crop yields D) More pesticide use and better crop yields
C) Less pesticide use and better crop yields
53) Digests damaged organelles
C) Lysosome
81) During which phase of mitosis do the centromeres line up along the cell equator?
C) Metaphase
47) A recessive allele on the X chromosome causes color deficiency. A color-deficient boy has a mother with normal vision and a color-deficient father. From which parent did he get the color-deficiency gene?
C) Mother
28) In aerobic cellular respiration, the ETC receives electrons directly from A) FADH2 only. B) ATP only. D) NADH only. E) NADH and ATP.
C) NADH and FADH2.
2) If you examined the human body on a chemical composition basis, which of the following 2) combinations of elements would be most common? A) C, H, Ca, Cl B) O, C, P, S C) O, C, H, N D) O, C, N, Na E) C, N, Ca, S
C) O, C, H, N
27) Which of the following techniques amplifies a specific region of DNA? A) DNA profiles B) Gel electrophoresis C) PCR D) The use of DNA probes
C) PCR
55) Which is the correct sequence of viral replication? A) Penetration → transcription → assembly → genetic material replication → protein synthesis B) Penetration → genetic material replication → transcription → assembly → protein synthesis C) Penetration → genetic material replication → transcription → protein synthesis → assembly D) Genetic material replication → penetration → transcription → assembly → protein synthesis E) Transcription → penetration → genetic material replication → assembly → protein synthesis
C) Penetration → genetic material replication → transcription → protein synthesis → assembly
41) During which phase do chromosomes first become visible?
C) Prophase
48) Under favorable conditions, during which phase of meiosis will the chromosomes appear as packets of four chromatids?
C) Prophase I
67) Some plans for weight loss include eating a low-carbohydrate diet. In the absence of a lot of glucose in the diet, what other food molecules can be used to extract energy for cellular respiration?
C) Protein and fats
17) In general, which of the following is (are) largely responsible for moving substances across the plasma membrane, communicating with other cells, and identifying the cell? A) Phospholipids B) Cytoskeleton C) Proteins D) Nucleic acids E) Carbohydrates
C) Proteins
55) The four polypeptides that are joined together to make functional hemoglobin represent which level of protein organization? A) Tertiary structure B) Primary structure C) Quaternary structure D) Secondary structure
C) Quaternary structure
34) Which statement correctly describes transcription? A) RNA chains of all genes are synthesized from the same DNA strand, with the growing RNA strand always starting at the 5' end and moving toward the 3' end. B) RNA chains of all genes are synthesized from the same DNA strand, with the growing RNA strand always starting at the 3' end and moving toward the 5' end. C) RNA chains of different genes can be transcribed from either DNA strand, with RNA polymerase traveling from the 3' end and moving toward the 5' end. D) RNA chains of different genes can be transcribed from either DNA strand, with RNA polymerase traveling from the 5' end and moving toward the 3' end.
C) RNA chains of different genes can be transcribed from either DNA strand, with RNA polymerase traveling from the 3' end and moving toward the 5' end.
23) In prokaryotes, the term prokaryotic fission specifically refers to
C) asexual reproduction.
53) Which of the following synthesizes RNA molecules in the nucleus? A) Messenger RNA B) Transfer RNA C) RNA polymerase D) DNA E) Ribosomal RNA
C) RNA polymerase
38) What is the site of protein synthesis in the cell? A) Eukaryotic chromosome B) Nucleus C) Ribosome D) Smooth endoplasmic reticulum E) Nucleolus
C) Ribosome
32) Which of the following is associated with rough ER? A) Plasma membrane B) Chlorophyll C) Ribosomes D) Lipid synthesis E) DNA
C) Ribosomes
39) Chromosomes are duplicated during what portion of the cell cycle?
C) S
58) ________ replication is the process when DNA uses one parental strand and synthesizes a new strand, resulting in each daughter cell having a new and parental DNA strand.
C) Semiconservative
13) Which of the following statements is NOT true?
C) Sexual reproduction produces clones.
28) How does DNA move during gel electrophoresis? A) DNA moves at a constant rate, regardless of fragment size. B) Larger pieces of DNA move at a faster rate. C) Smaller pieces of DNA move faster toward the positive electrode. D) The DNA moves toward the negative electrode.
C) Smaller pieces of DNA move faster toward the positive electrode.
40) What is the function of a plant cell vacuole? A) Initiates division of the cell B) Packages proteins for export C) Stores water D) Replicates chromosomes
C) Stores water
42) Which step produces the most ATP?
C) The ETC
44) Which of the following processes occurs across the mitochondrial membrane?
C) The ETC
45) Which of the following processes involves hydrogen ions moving through ATP synthase channels, generating ATP molecules?
C) The ETC
47) During which of the following processes is CO2 produced?
C) The Krebs cycle
38) Which of the following is an example of hydrogen bonding? A) The bond between H of one water molecule and H of a separate water molecule B) The bond between the H of a water molecule and H of a hydrogen molecule C) The bond between O of one water molecule and H of a separate water molecule D) The bond between O and H in a single molecule of water E) The bond between O of one water molecule and O of a separate water molecule
C) The bond between O of one water molecule and H of a separate water molecule
76) Which of the following is correct?
C) The chromosomes shorten and thicken during prophase.
39) Imagine you do a test cross between a purple-flowered pea plant having serrated leaves (both dominant traits) and a white-flowered pea plant having smooth edges. If the purple-flowered plant is heterozygous for both traits, the expected ratio in the offspring is 1 purple-serrated:1 purple-smooth:1 white-serrated:1 white-smooth. Instead, you see 7 purple-serrated:1 purple-smooth:1 white-serrated:7 white-smooth. What is the explanation of this ratio?
C) The genes are linked.
13) Dehydration synthesis involves the removal of a hydrogen ion and a hydroxyl ion. What happens next? A) The hydrogen ion becomes an isotope. B) A large polymer is split apart into small monomers. C) The hydrogen and hydroxyl ions combine to form water. D) A polysaccharide is released from a monosaccharide.
C) The hydrogen and hydroxyl ions combine to form water.
37) What happens when diffusion moves molecules across the plasma membrane? A) Energy input is required to transport molecules. B) The cell gains needed materials and gets rid of excess materials very quickly. C) The process is relatively slow and is driven by concentration gradients. D) Most molecules are capable of crossing the phospholipid bilayer at any location and at basically the same rate. E) The rate of diffusion cannot be influenced by the cell.
C) The process is relatively slow and is driven by concentration gradients.
4) What differentiates gram-positive bacteria from gram-negative bacteria? A) The use of oxygen B) Nutrient requirements C) The way the cell wall stains D) The means of locomotion E) The appearance of colonies
C) The way the cell wall stains
2) Peptidoglycan is found in the cell walls of A) plants. B) viruses. C) bacteria. D) archaea. E) fungi.
C) bacteria.
44) In a wild-type strain of fruit flies, the length of a gene from the start to the stop codon is 2,000 DNA bases. Suppose an experiment indicated that the mRNA molecule transcribed from this gene is much shorter (only 1,200 bases). What is the most likely explanation for this? A) The first 800 bases of DNA are always cut out as it is transcribed into mRNA. B) The mRNA was prematurely degraded. C) There are introns in the DNA that were cut out of the mRNA. D) A mutation caused the formation of an extra stop codon in the gene.
C) There are introns in the DNA that were cut out of the mRNA.
47) How do buffers work? A) They accept and release OH-. B) They monitor the blood pH. C) They accept and release H+. D) They convert H+ and OH- to water. E) They soak up extra acid and base.
C) They accept and release H+
44) Which of the following statements about lipids is incorrect? A) They are used for energy storage. B) They are large chains of nonpolar hydrocarbons. C) They are short chains of polar hydrocarbons. D) They are hydrophobic and water insoluble. E) They are primary component of cell membranes.
C) They are short chains of polar hydrocarbons.
37) Which statement is an accurate description of water molecules? A) They are uncharged and nonpolar. B) They are charged and nonpolar. C) They are slightly charged and polar. D) They are ionically bonded.
C) They are slightly charged and polar.
25) How many CO2 molecules are generated from each pyruvate molecule that enters the mitochondrial matrix?
C) Three
49) Which of the following has anticodons? A) DNA B) Messenger RNA C) Transfer RNA D) RNA polymerase E) Ribosomal RNA
C) Transfer RNA
20) Which of the following groups includes carrier and channel proteins? A) Recognition proteins B) Receptor proteins C) Transport proteins D) Connection proteins
C) Transport proteins
37) Which of the following "buds off" of the Golgi complex? A) Ribosomes B) Cells C) Vesicles D) Cytoskeleton E) Nuclei
C) Vesicles
77) All animals need oxygen gas (O2) for their primary cellular-level functioning. Inside the cell, O2 is split apart into oxygen atoms. Eventually, electrons that are flowing through the cell will be "received" by this oxygen. But first, the electrons combine with protons present in the cell to form a basic element that has a single proton and a single electron. Then this element combines with the oxygen to form a certain chemical compound. In this scenario, what chemical compound is produced when this element combines with oxygen? A) Ozone (O3) B) Bicarbonate (HCO3) C) Water (H2O) D) Carbon dioxide (CO2)
C) Water (H2O)
63) Which of the following conditions may cause infertility in a human?
C) XXY
63) The specific heat of water is 10 times greater than that of iron. You place a metal pot full of water on the stove to heat it up. You touch the metal handle of the pot when the water is still only lukewarm. Which of the following best describes what happens? A) You find that the handle is cooler than the water in the pot. B) You find that both the water and the handle are the same temperature. C) You burn your finger and pull your hand away from the hot metal handle. D) You determine that metal pots full of water produce acids and bases.
C) You burn your finger and pull your hand away from the hot metal handle.
60) A gene can be mutated with no resulting functional change in the protein that is produced from that gene if A) an entire codon has been removed. B) the mutation alters the active site of an enzyme. C) a codon has changed, but it codes for the same amino acid as the original codon. D) RNA polymerase can edit the mutation from the mRNA produced during translation.
C) a codon has changed, but it codes for the same amino acid as the original codon.
28) For diffusion to occur, there must be A) water. B) a membrane. C) a gradient. D) ATP.
C) a gradient.
39) When a cell divides, each daughter cell receives
C) a nearly perfect copy of the parent cell's genetic information.
9) All of the following are found in DNA EXCEPT
C) a phospholipid group.
23) The different forms of a gene-for example, those responsible for eye color-are called
C) alleles
31) Alternative forms of a gene (such as those responsible for eye color) are called A) telomeres. B) sister chromatids. D) receptors. E) cyclins.
C) alleles.
1) The sequence of nitrogen-containing bases on one strand of DNA most directly determines the sequence of A) sugars in a polysaccharide molecule. B) bases in a protein molecule. C) amino acids in a protein molecule. D) fatty acids in a fat molecule.
C) amino acids in a protein molecule.
45) All of the following have been produced by inserting human genes into bacteria EXCEPT A) blood-clotting enzymes, which treat hemophiliacs. B) insulin, which treats diabetics. C) cancer-cell-killing hormones, which cure patients who have malignancies. D) growth hormone, which helps children grow normally. E) clot-dissolving enzymes, which help heart attack victims recover.
C) cancer-cell-killing hormones, which cure patients who have malignancies.
20) An example of a structural polysaccharide is A) starch. B) glucose. C) cellulose. D) glycogen. E) maltose.
C) cellulose
31) The site on a chromosome where microtubules attach during cell division is the
C) centromere.
55) Each chromosome consists of two
C) chromatids
34) Oxygen is necessary for cellular respiration because oxygen
C) combines with electrons and hydrogen ions to form water.
101) Cdks are activated only when they bind to
C) cyclin.
68) Your tongue does NOT grow hair because A) skin cells have extra DNA that codes for hair proteins. B) saliva prevents hair from growing. C) different genes are expressed in different tissues. D) the genes for hair proteins have been deleted from the cells of your tongue.
C) different genes are expressed in different tissues.
9) If, in a heterozygous individual, only one allele is expressed in the phenotype, that allele is
C) dominant
13) When a cell divides via asexual reproduction
C) each daughter cell receives a nearly perfect copy of the parent cell's genetic information.
41) Semiconservative DNA replication means that
C) each new DNA molecule has half the DNA from the old one.
41) The inner membrane of the mitochondria can be compared functionally to the thylakoid membranes of the chloroplast because both contain a system for
C) electron transport.
27) Polar covalent bonds form when A) more than one pair of electrons is shared. B) an acid and a base are combined. C) electrons are shared unequally between atoms. D) atoms from two molecules are repelling each other. E) ions are formed.
C) electrons are shared unequally between atoms.
29) In the mitochondrial matrix reactions, the original carbons in pyruvate
C) end up in molecules of CO2.
52) The secretion of excess water via a contractile vesicle of a Paramecium cell is an example of A) simple diffusion. B) active transport. C) exocytosis. D) osmosis. E) facilitated diffusion.
C) exocytosis.
22) The element carbon has atomic number 6. Carbon most likely A) donates two electrons to another atom. B) shares two electrons with another atom. C) forms four covalent bonds. D) forms ionic bonds with other atoms.
C) forms four covalent bonds.
71) During meiosis, the cytokinesis that follows telophase II results in
C) four haploid cells.
12) The formation of ions involves the A) sharing of protons. B) gain or loss of neutrons. C) gain or loss of electrons. D) sharing of electrons. E) gain or loss of protons.
C) gain or loss of electrons.
45) A freshwater protozoan, such as Paramecium, tends to ________ because it lives in a ________ environment. A) lose water; hypotonic B) gain water; isotonic C) gain water;hypotonic D) lose water; hypertonic E) gain water; hypertonic
C) gain water;hypotonic
71) Protein channels that provide passage for hormones and nutrients between animal cells are termed A) desmosomes. B) tight junctions. C) gap junctions. D) plasmodesmata.
C) gap junctions.
1) Gregor Mendel concluded that each pea has two units for each trait, and each gamete contains one unit. Mendel's "units" are now called
C) genes.
24) Sexual reproduction allows for
C) greater genetic diversity in offspring compared to asexual reproduction
73) In flowering plants, pollen represents the
C) haploid stage.
67) Unlike a rock, a reptile can sit in the hot sunshine without its body temperature soaring quickly. This is because the water in its body A) has a low specific heat. B) is a poor solvent. C) has a high specific heat. D) is a good solvent.
C) has a high specific heat.
34) Polar molecules A) are always ions. B) have an equal distribution of electric charge. C) have an unequal distribution of electric charge. D) have an overall negative electric charge. E) have an overall positive electric charge.
C) have an unequal distribution of electric charge.
13) ISO membranes are inside-out membrane vesicles used by researchers in membrane studies. As a molecule diffuses into the vesicle, it will encounter the layers of the membrane in the following order A) head-tail-head-tail. B) tail-head-tail-head. C) head-tail-tail-head. D) head-head-tail-tail. E) tail-head-head-tail.
C) head-tail-tail-head.
11) When the two gametes that fuse to form a zygote contain different alleles of a given gene, the offspring is
C) heterozygous.
19) The two polynucleotide chains in a DNA molecule are attached to each other by
C) hydrogen bonds between bases.
18) Complementary base pairs are held together by
C) hydrogen bonds.
47) The blood plasma of a man who drinks salt water will become ________ to his red blood cells, whereas the red blood cells will be ________ to the blood plasma. A) isotonic; isotonic B) isotonic; hypertonic C) hypertonic; hypotonic D) hypertonic; isotonic E) hypotonic; hypertonic
C) hypertonic; hypotonic
46) Solutions that cause water to enter cells by osmosis are called A) permeable. B) hydrophilic. C) hypotonic. D) isotonic. E) hypertonic.
C) hypotonic.
42) Crossing over
C) increases variability in gametes.
57) All of the following are ways in which scientists can transfect an organism EXCEPT A) using a "gene gun" to shoot genes into cells in culture. B) spraying plants with herbicide containing new genes. C) infecting a host organism with a virus carrying a new gene. D) injecting DNA into an egg using a small, sharp pipette.
C) infecting a host organism with a virus carrying a new gene.
6) The hydrophobic tails of a phospholipid bilayer are oriented toward the A) cytoplasm of the cell. B) both the extracellular fluid and cytoplasm. C) interior of the plasma membrane (i.e., toward one another). D) interstitial fluid. E) extracellular fluid surrounding the cell.
C) interior of the plasma membrane (i.e., toward one another).
18) An advantage of sexual reproduction and meiosis is that
C) it increases genetic diversity.
9) Bacterial endospores are used for A) bioremediation. B) attracting viruses. C) keeping the bacteria alive under harsh conditions. D) forming biofilms. E) bacterial reproduction.
C) keeping the bacteria alive under harsh conditions.
22) Lactose is a disaccharide of glucose and galactose, and its digestion requires the actions of the enzyme lactase. If lactose is eaten as part of the diet but is not digested by lactase, this sugar is then metabolized by bacteria in the intestine, leading to the symptoms of lactose intolerance. Lactose intolerance, therefore, results from a(n) A) lack of dehydration synthesis of lactose. B) inability of the body to produce lactose. C) lack of hydrolysis of lactose. D) low blood lactose level.
C) lack of hydrolysis of lactose.
65) Human muscle cells can perform
C) lactic acid fermentation and aerobic cellular respiration.
1) The substances in cell membranes that form a barrier to the movement of materials across the membrane are A) internal proteins. B) nucleic acids. C) lipids. D) external proteins. E) carbohydrates.
C) lipids.
30) Triglycerides are A) always composed of carbon rings. B) a main component of cellular membranes. C) made from glycerol and fatty acids. D) hydrophilic. E) polymers of amino acids.
C) made from glycerol and fatty acids.
61) In eukaryotes, gametes are produced by
C) meiosis.
66) The spindle apparatus is made of
C) microtubules.
24) In the comparison of a DNA molecule to a twisted ladder, the rungs (footholds) of the ladder are
C) nitrogenous bases linked together.
31) In reference to diffusion, passive really means A) without a membrane. B) very slowly. C) no energy required. D) in the air. E) no gradient.
C) no energy required.
55) A gene mutation is defined as change in the A) structure of ribosomes. B) activation of a gene. C) nucleotide sequence of DNA. D) nucleotide sequence of RNA.
C) nucleotide sequence of DNA.
91) Mitosis is division of the ________, whereas cytokinesis is division of the ________.
C) nucleus
20) Strictly speaking, mitosis and meiosis are divisions of the
C) nucleus and chromosomes.
14) Membrane proteins are synthesized on ribosomes that are located A) on the Golgi apparatus. B) in the cytoplasm. C) on the rough endoplasmic reticulum. D) on the smooth endoplasmic reticulum. E) in the nucleus.
C) on the rough endoplasmic reticulum.
16) In humans, the male determines the sex of the child because males have
C) one X and one Y chromosome
36) To say that a cell is "selectively permeable" means A) sometimes water passes through, and sometimes it can't. B) it is permeable to different substances than other cells. C) only certain molecules can pass through. D) it has different-sized perforations in the membrane. E) permeability depends on gradient differences.
C) only certain molecules can pass through.
35) When substances move across a plasma membrane and down concentration gradients, this is called A) exocytosis. B) pinocytosis. C) passive transport. D) active transport.
C) passive transport.
61) The process in which white blood cells engulf bacteria is termed A) exocytosis. B) recognition. C) phagocytosis. D) pinocytosis. E) reception.
C) phagocytosis.
4) All of the following may be found in a DNA nucleotide EXCEPT
C) phospholipid.
50) A particular cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. It could be a(n) ________ cell. A) plant or bacterial B) animal, but not a plant C) plant or animal D) plant, but not an animal E) bacterial
C) plant or animal
64) The small, circular loops of DNA in prokaryotic cells that are separate from the main chromosome and may carry genes associated with antibiotic resistance are called A) ribosomes. B) pili. C) plasmids. D) plastids. E) cristae.
C) plasmids.
52) The fact that salt dissolves in water is best explained by the) A) hydrophobic nature of salt. B) slightly charged nature of water molecules. C) polar nature of water molecules. D) hydrophobic nature of the water. E) ionic nature of water molecules.
C) polar nature of water molecules.
55) When the expression of a trait is influenced by the action of many genes, the pattern of inheritance is called
C) polygenic inheritance.
42) All of the following cells contain mitochondria EXCEPT A) eukaryotic cells. B) animal cells. C) prokaryotic cells. D) plant cells.
C) prokaryotic cells.
25) The most common method of bacterial reproduction is
C) prokaryotic fission.
31) Ribosomes are the site of ________ synthesis. A) nucleoli B) glucose C) protein D) RNA E) DNA
C) protein
23) Cell membranes do all of the following EXCEPT A) isolate the cell's contents from the external environment. B) regulate the movement of substances between the cytoplasm of the cell and the extracellular fluid. C) provide an energy source for the cell. D) allow communication between cells. E) provide attachments between cells.
C) provide an energy source for the cell.
20) Mutations that improve the survival and reproduction of organisms, and thus contribute to the evolution of species, arise rapidly in prokaryotes due to their A) sexual reproduction. B) cell wall composition. C) rapid rate of cell division. D) absence of a nucleus. E) anaerobic metabolism.
C) rapid rate of cell division.
63) Cells use exocytosis to A) ingest nutrients. B) pump hydrogen molecules across the membrane. C) release substances from the cell. D) move away from danger. E) create new cells.
C) release substances from the cell.
15) Binary fission is the method by which bacteria A) acquire genetic variation. B) move to new locations. C) reproduce. D) survive extreme conditions for long periods of time. E) metabolize without oxygen.
C) reproduce.
30) The enzymes used to cut genes in recombinant DNA research are called A) spliceosomes. B) DNA polymerases. C) restriction enzymes. D) RNA polymerases. E) replicases.
C) restriction enzymes.
52) All of the following are dependent on cilia EXCEPT the A) oviduct in mammals. B) gills of oysters. C) sperm of animals. D) respiratory tract of vertebrates.
C) sperm of animals.
54) What structure is responsible for moving the chromosomes during mitosis?
C) spindle
29) Cholesterol, testosterone, and estrogen are examples of A) proteins. B) waxes. C) steroids. D) nucleic acids. E) fatty acids.
C) steroids.
65) If a frog egg cell is placed into a hypotonic solution, it will A) shrivel via active transport. B) shrivel via osmosis. C) swell via osmosis. D) swell via facilitated diffusion. E) shrivel via facilitated diffusion.
C) swell via osmosis.
42) All of the following occur during DNA replication EXCEPT.
C) synthesis of totally new double-stranded DNA molecules.
60) Sweating is a useful cooling mechanism for humans because water A) is an outstanding solvent. B) takes up a great deal of heat in changing from its solid state to its liquid state. C) takes up a great deal of heat in changing from its liquid state to its gaseous state. D) can exist in two states at temperatures common on Earth. E) ionizes readily.
C) takes up a great deal of heat in changing from its liquid state to its gaseous state.
23) Some of the CO2 that is exhaled during breathing is created during
C) the conversion of pyruvate to acetyl CoA.
41) The manufacture of proteins from RNA and amino acids is referred to as A) transcription. B) replication. C) translation. D) transformation. E) activation.
C) translation.
82) The ant Myrmecia pilosula has the smallest number of chromosomes possible in a eukaryote: females possess only one pair of chromosomes, and males have only one chromosome! Put another way, female M. pilosula can be described as having the haploid condition n = 1 and the diploid condition 2n = 2. Based on this scenario as well as your knowledge of gamete formation, a female M. pilosula can produce gametes with ________ different sets of chromosomes.
C) two
16) Maltose is made from A) glucose and fructose. B) two peptides. C) two glucose molecules. D) glucose and galactose.
C) two glucose molecules.
1) At the end of glycolysis, the original carbons of the glucose molecule form
C) two molecules of pyruvate.
73) Imagine that it is 1965 and the bacterium Thermus aquaticus has not yet been discovered. As a geneticist interested in forensics applications, you are attempting to develop a gene-amplifying technique similar to PCR. In a test tube, you place a DNA sample, free nucleotides, human DNA polymerase, and the appropriate primers for the DNA sequence being analyzed. You first heat the sample to 90°C, then cool it to 50°C, and then reheat it to 70°C. Based on this scenario and your knowledge of how modern PCR works, the result of these procedures will be A) successful copying of the DNA, because it follows modern PCR procedures almost perfectly. B) unsuccessful, because the enzyme will denature during the third step (reheating). C) unsuccessful, because the enzyme will denature during the first step (heating). D) unsuccessful, because the enzyme will denature during the second step (cooling). E) unsuccessful, because human DNA polymerase cannot recognize the primers used.
C) unsuccessful, because the enzyme will denature during the first step (heating).
47) The common cold is caused by a A) bacterium. B) prion. C) virus. D) viroid. E) fungus.
C) virus.
50) AIDS is caused by a A) bacterium. B) prion. C) virus. D) viroid. E) fungus.
C) virus.
52) Herpes is caused by a A) bacterium. B) prion. C) virus. D) viroid. E) fungus.
C) virus.
53) Rabies is caused by a A) bacterium. B) prion. C) virus. D) viroid. E) fungus.
C) virus.
75) You discover a new particle. It has only RNA as a nucleic acid and lacks both a membrane and cytoplasm. This particle is a(n) A) archaea. B) bacteria. C) virus. D) fungus. E) prion.
C) virus.
55) Agents that cause mutations are called mutagens. All of the following are examples of mutagens EXCEPT
C) vitamins.
29) The function of the promoter is to signal the RNA polymerase A) where to add the first amino acid to the protein. B) which strand of the DNA to read. C) where to start transcribing the DNA. D) where to start translating the DNA.
C) where to start transcribing the DNA.
Which of the following molecules is a monosaccharide? (eText Concept 5.2) * C25H43O8 * C22H49O10N5 * C51H98O6 * C45H84O8PN * C6H12O6
C6H12O6 Correct. Monosaccharides have molecular formulas that are multiples of CH2O.
Two similar-sized animal cells are placed in a 0.5% sucrose solution. Cell A enlarges for a while and then stops; cells B continues to enlarge and finally ruptures. Which if the following must have been TRUE at the beginning of the experiment?
Cell B was hypertonic to cell A.
which of the following statements about chloroplasts and mitochondria is true? (eText Concept 6.5) * Chloroplasts and mitochondria are components of the endomembrane system. * Mitochondria but not chloroplasts contain a small amount of DNA. * Chloroplasts and mitochondria have three sets of membranes. * Chloroplasts and mitochondria synthesize some of their own proteins. * Chloroplasts but not mitochondria are completely independent of the cell of which they are a part.
Chloroplasts and mitochondria synthesize some of their own proteins.
High cholesterol levels are considered a major risk factor for heart disease. If it is so bad for humans, why does the body make cholesterol in the first place? (eText Concept 5.3) * Cholesterol aids in the formation of amino acids that are used to build proteins. * Cholesterol is an important energy storage molecule. * Cholesterol is an important constituent of nucleotides. * Cholesterol is not important for humans any more. It is a holdover from hunter-gatherer days when food was scarce. * Cholesterol is the basis for many important molecules such as sex hormones.
Cholesterol is the basis for many important molecules such as sex hormones. Correct. Cholesterol is the basis for many steroid molecules, including sex hormones.
Which of the following is false in respect to cells' chromosomes? (eText Concept 6.3) * All cells possess one or more chromosomes. * Chromosomes are present throughout a cell's reproductive cycle. * Chromosomes only exist when cells are actively synthesizing proteins. * Chromosomes only appear as a cell is about to divide. * None of the listed responses is false.
Chromosomes only appear as a cell is about to divide.
72) A disorder caused by nondisjunction of chromosome 21, resulting in a trisomy 21 child, is
D) Down syndrome.
Which statement about the cytoskeleton is true? (eText Concept 6.6) * Components of the cytoskeleton often mediate the movement of organelles within the cytoplasm. * Microfilaments are more permanent structures in cells compared to intermediate filaments and microtubules. * Microtubules are chains of proteins that resist stretching. * Intermediate filaments are hollow tubes of protein that provide structural support. * Plant cells lack a cytoskeleton because they have a rigid cell wall.
Components of the cytoskeleton often mediate the movement of organelles within the cytoplasm.
Which of the following statements about cotransport of solutes across a membrane is correct? (eText Concept 7.4) * Cotransport involves the hydrolysis of ATP by the transporting protein. * In cotransport, both solutes that are being transported are moving down their chemical gradients. * A cotransport protein is most commonly an ion channel. * The sodium-potassium pump is an example of a cotransport protein. * Cotransport proteins allow a single ATP-powered pump to drive the active transport of many different solutes.
Cotransport proteins allow a single ATP-powered pump to drive the active transport of many different solutes. Correct. The electrochemical gradient created by a single ATP-dependent pump can drive the transport of many different solutes using cotransport proteins.
17) Which is the correct sequence of increasing organization? A) Molecule, cell, organelle, organ B) Organelle, tissue, cell, organ C) Organ tissue, cell, molecule D) Cell tissue, organ, organ system E) Atom, molecule, tissue cell
D
25) All of the following are important to the theory of evolution EXCEPT A) mutations. B) variation in traits within an entire population. C) inheritance of traits. D) changes in individuals within their lifetimes. E) environmental change.
D
34) Chromosomes are made of A) DNA. B) cells. C) carbohydrates. D) DNA and proteins. E) proteins.
D
36) Adaptations include all of the following EXCEPT A) larger body size in male gorillas which fight over females. B) reduced heart rate and oxygen consumption in seals that dive deep for long periods of time. C) inborn migratory behavior of young birds born in the Arctic. D) teaching a pet parrot to talk.
D
39) All of the following are true of all living organisms EXCEPT that they A) are made of cells. B) can reproduce themselves. C) can grow. D) possess either DNA or RNA. E) respond to stimuli.
D
4) Which of the following is FALSE about scientific theories? 4) A) They can be either supported or modified by new observations. B) They are used to support observations using deductive reasoning. C) They have been thoroughly tested. D) They are firmly established and cannot be refuted. E) They are developed by inductive reasoning.
D
41) Why do humans born without sweat glands usually not survive? A) Sweat glands create openings in the skin where gas exchange occurs. B) Sweating is important for eliminating impurities from the body. C) Sweating is the only way the body eliminates excess water. D) Sweating is an important mechanism for maintaining the correct body temperature.
D
42) An organism's ability to detect stimuli from either the internal or external environment is called A) natural selection. B) evolution. C) mutation. D) responsiveness. E) DNA.
D
70) Which of the following metabolic processes directly utilizes oxygen?
D) ETC
5) Which of these would be an example of a NON-scientific study? A) A company uses different advertising methods for a product to determine which one produces the most sales. B) NASA sends tadpoles up in the space shuttle to see how gravity affects their development. C) People are immunized with different vaccines to determine their relative effectiveness against the flu virus. D) Consumers are asked which tomato variety produces the best-tasting spaghetti sauce. E) A study determines differences in the species composition in two parks.
D
54) Of the following levels of organization, Archaea have A) atoms, molecules, and organs. B) molecules only. C) atoms only. D) atoms and molecules. E) organs only.
D
56) In which kingdom does a multicellular, eukaryotic, photosynthetic organism belong? A) Fungi B) Animalia C) Protists D) Plantae
D
61) A cell that lacks organelles is a(n) A) animal cell. B) member of the Kingdom Plantae. C) eukaryotic cell. D) prokaryotic cell.
D
22) Modern forensic biotechnology labs use sophisticated machines to analyze ________, such as D16, and to determine the number of specific genetic repeats in the samples. A) PCRs B) AIDs C) primers D) (STRs)
D) (STRs)
23) Sodium (Na), atomic number 11, has a tendency to lose an electron in the presence of chlorine. After losing the electron, Na has ________ protons in its nucleus. A) 10 B) 12 C) 22 D) 11 E) 21
D) 11
50) Suppose an organism can alternate between aerobic and anaerobic respiration. If it had to use anaerobic respiration exclusively, how many glucose molecules must it break down to generate the same ATP as it would in aerobic respiration?
D) 19
11) During glycolysis, what is the net gain of ATP molecules produced from one glucose molecule?
D) 2
48) Proteins are constructed using how many different amino acids? A) 4 B) 1,000 C) 100 D) 20 E) More than 5,000
D) 20
17) In humans, gametes contain
D) 22 autosomes and 1 sex chromosome.
33) In pea plants, tall plants are dominant over short, and green pods are dominant over yellow. If you crossed true-breeding tall, green-podded plants with true-breeding short, yellow-podded plants, and then crossed the F1 individuals among themselves, what proportion of the F2 offspring would you expect to be tall and yellow-podded?
D) 3/16
40) Suppose one strand of a "mini-gene" has the base sequence TACCCGGATTCA. If we assume no introns are involved, how many amino acids does the polypeptide encoded by this gene have? A) 2 B) 6 C) 12 D) 4
D) 4
8) What is the total number of different possible combinations of bases in a codon? A) 4 B) 20 C) 3 D) 64
D) 64
12) If we cross two pea plants, each heterozygous for yellow seed color genes, the expected ratio of yellow:green among the offspring will be
D) 75% yellow:25% green.
11) The 'rule" formulated by Chargaff states that
D) A = T and G = C in any molecule of DNA.
30) Which type of eukaryotic cell contains two types of each chromosome?
D) A diploid cell
49) Which of the following is the thinnest? A) A flagellum B) An intermediate filament C) A microtubule D) A microfilament
D) A microfilament
38) Which of the following has no organelles, ribosomes, or cytoplasm? A) A bacterium B) A plant C) An alga D) A virus E) A cyanobacterium
D) A virus
55) Prenatal diagnosis is available for all of the following disorders EXCEPT A) Down syndrome. B) cystic fibrosis. C) sickle-cell anemia. D) AIDS.
D) AIDS.
19) The overall products of glycolysis are
D) ATP, NADH, and pyruvate.
6) The main function of cellular respiration is to produce
D) ATP.
4) Which of the following is noted when comparing DNA and RNA? A) Only DNA has a backbone made up of sugars and phosphates. B) Thymine pairs with different bases in DNA and RNA. C) Hydrogen bonding is important only in DNA. D) Adenine pairs with different bases in DNA and RNA. E) No sugar is present in either molecule.
D) Adenine pairs with different bases in DNA and RNA.
65) Which of the following is NOT a means of regulating gene expression? A) Modifying proteins after they are synthesized B) Regulating how long a protein lasts in a cell C) Varying the rate at which messenger RNAs are translated D) Deleting genes from cells in which they are not needed E) Varying the rate at which messenger RNAs are transcribed
D) Deleting genes from cells in which they are not needed
8) A phosphate group binds to what molecule to create the "backbone" of the DNA molecule?
D) Deoxyribose
65) Autosomal nondisjunction can result in
D) Down syndrome.
20) Scientists recommend a diet rich in antioxidants to stay healthy. What occurs at the atomic level to 20) explain this recommendation? A) Antioxidants cause an increase in pH, which is necessary for neutrality in cells. B) Antioxidants steal electrons, which gives cells extra energy. C) Antioxidants are inert and do not interact with free radicals. D) Antioxidants prevent free radicals from attacking other atoms or molecules.
D) Antioxidants prevent free radicals from attacking other atoms or molecules.
3) Which of the following components is NOT part of the modern cell theory? A) All cells arise from preexisting cells. B) Cells are the functional units of multicellular organisms. C) All living organisms are made up of one or more cells. D) Bacteria are examples of eukaryotic cells. E) The smallest living organisms are single cells.
D) Bacteria are examples of eukaryotic cells.
56) When the acidic level of human blood increases, how is the proper balance of hydrogen ions (H +) restored? A) H+ ion-donor levels increase. B) Carbonic acid eats up the extra OH- ions. C) Bicarbonate (HCO3-) releases H+ ions that combine with excess OH- ions to form H2O. D) Bicarbonate (HCO3-) accepts H+ ions and forms carbonic acid.
D) Bicarbonate (HCO3-) accepts H+ ions and forms carbonic acid.
10) Which of the following is an example of asexual reproduction in eukaryotes?
D) Budding in the protistan Hydra
5) Which four elements make up approximately 96% of living matter? 5) A) Carbon, phosphorus, hydrogen, sulfur B) Carbon, oxygen, calcium, sulfur C) Oxygen, hydrogen, calcium, sodium D) Carbon, hydrogen, nitrogen, oxygen E) Carbon, sodium, chlorine, magnesium
D) Carbon, hydrogen, nitrogen, oxygen
19) What is the longest-lasting phase of the prokaryotic cell cycle?
D) Cell growth and DNA replication
50) What is one difference in mitosis and meiosis during anaphase I?
D) Chromatids do not separate at the centromere in anaphase I.
33) The cause of tetanus is A) Borrelia burgdorferi. B) Campylobacter. C) Streptococcus pneumoniae. D) Clostridium tetani. E) Escherichia coli.
D) Clostridium tetani.
51) Which of the following is NOT correct?
D) Cytokinesis is a part of mitosis.
10) Where does the production of pyruvate occur during glycolysis?
D) Cytoplasmic fluid
18) Of the following cell components, which is composed of protein fibers that provide shape and organization to eukaryotic cells? A) Golgi complex B) Chromatin C) DNA D) Cytoskeleton E) Mitochondria
D) Cytoskeleton
11) Which of the following molecules function to transfer genetic information from one generation to the next? A) Protein molecules B) mRNA C) Lipid molecules D) DNA E) tRNA
D) DNA
1) The hereditary material present in all cells is
D) DNA.
16) Which statement is TRUE of the behavior of chromosomes in mitosis?
D) Each new cell receives copies of all the original chromosomes.
21) During which step of aerobic respiration is oxygen used?
D) Electron transport chain (ETC)
56) Glucose is a six-carbon sugar that diffuses slowly through artificial phospholipid bilayers. The cells lining the small intestine, however, rapidly move large quantities of glucose from the glucose-rich food into their glucose-poor cytoplasm. Given this information, which transport mechanism is most probably functioning in the intestinal cells? A) Simple diffusion B) Aquaporin transport C) Exocytosis D) Facilitated diffusion E) Osmosis
D) Facilitated diffusion
67) How many haploid cells are produced by one diploid cell during meiosis?
D) Four
60) In eukaryotic cells, which of the following can occur during the stages of mitosis?
D) Fragmentation and disappearance of nuclear envelope and nucleolus
27) What is the difference between free and attached ribosomes? A) Free ribosomes produce proteins, whereas attached ribosomes produce carbohydrates. B) Free ribosomes are readily "used up" by the cell and are replaced frequently, whereas attached ribosomes remain functional for the lifetime of the cell. C) Free ribosomes produce proteins that are exported from the cell, whereas attached ribosomes make proteins for mitochondria and chloroplasts. D) Free ribosomes are located in the cytoplasm, whereas attached ribosomes are embedded on the endoplasmic reticulum.
D) Free ribosomes are located in the cytoplasm, whereas attached ribosomes are embedded on the endoplasmic reticulum.
53) Beginning with a newly formed daughter cell, what is the order of the other stages of the eukaryotic cell cycle?
D) G1, S, G2, mitosis
7) Which of the following reactions is an example of dehydration synthesis? A) Glycogen → glucose subunits B) Peptide → alanine + glycine C) Fat → fatty acids + glycerol D) Glucose + galactose → lactose E) Cellulose → glucose
D) Glucose + galactose → lactose
26) When the level of glucose in your blood is high, your body is able to store excess glucose in the liver by forming glycogen. When blood glucose levels fall, this stored glucose can be released. Based on this information, which of the following is TRUE? A) Glycogen is a highly branched functional group that forms a larger glucose polymer. B) Glucose is a polysaccharide that can join to form the monosaccharide glycogen. C) Glucose is not an organic molecule, but glycogen is an organic molecule. D) Glycogen is a polysaccharide formed by joining excess monosaccharides of glucose.
D) Glycogen is a polysaccharide formed by joining excess monosaccharides of glucose.
105) Which of the following is the correct sequence in a cyclin-Cdk pathway?
D) Growth factor → receptor → cyclin → Cdk → DNA replication
28) Which of the following represents a molecule characterized by polar covalent bonding? 28) A) NaCl B) O2 C) H2 D) H2O E) CH4
D) H2O
43) Which of the following is a sex-linked recessive condition?
D) Hemophilia
54) Which of the following causes infectious sores on the mucous membranes of the mouth that occur during times of stress? A) Bacillus anthracis B) Listeria C) Escherichia D) Herpes virus E) Prions
D) Herpes virus
76) What is the reason for the prevalence of the sickle-cell allele in African populations?
D) Heterozygotes have some resistance to the parasite that causes malaria.
51) Which of the following properties of water enable(s) it to function as a regulator of temperature for living organisms? (Hint: Think about what happens when you are sunbathing.) A) High heat of vaporization B) High specific heat C) High specific heat and high heat of vaporization D) High specific heat and low heat of vaporization E) Low specific heat
D) High specific heat and low heat of vaporization
32) Which of the following distinguishes prophase 1 of meiosis from prophase of mitosis?
D) Homologous
38) Suppose ENZ-1 and ENZ-2 are two different restriction enzymes. If various pieces of DNA from different species are cut with these enzymes (as follows), which would most easily form recombinant molecules? A) Human DNA cut with ENZ-1 and gorilla DNA cut with ENZ-2 B) Bacterial DNA cut with ENZ-1 and bacterial DNA cut with ENZ-2 C) Human DNA cut with ENZ-1 and human DNA cut with ENZ-2 D) Human DNA cut with ENZ-2 and gorilla cut with ENZ-2
D) Human DNA cut with ENZ-2 and gorilla cut with ENZ-2
41) Which of the following best explains the attraction of water molecules to each other? A) Nonpolar covalent bond B) Polar covalent bond C) Ionic bond D) Hydrogen bond E) Electron-proton interaction
D) Hydrogen bond
31) Regarding the structure of DNA, which of the following joins adenine and thymine and also guanine and cytosine?
D) Hydrogen bonds
73) Suppose you have discovered a new virus and have isolated its nucleic acids. What feature could 73) you look for to determine whether the nucleic acids of this virus are RNA or DNA? A) If it is RNA, there will be no adenine. B) If is RNA, it will contain deoxyribose. C) If it is DNA, the virus will not contain proteins. D) If it is RNA, it will contain ribose.
D) If it is RNA, it will contain ribose.
37) Which of these statements concerning the centromere is NOT true?
D) It anchors proteins to DNA.
41) Which of the following biological molecules possess large nonpolar regions, making them insoluble in water? A) Carbohydrates B) Proteins C) Nucleic acids D) Lipids
D) Lipids
42) Which of the following groups is crucial to the structure and function of the sex hormones estrogen and testosterone? A) Proteins B) Carbohydrates C) Nucleic acids D) Lipids
D) Lipids
36) In comparing mitosis and meiosis, which of the
D) Meiosis II resembles mitosis.
68) What is a major difference between mitosis and meiosis?
D) Meiosis produces haploid cells, whereas mitosis produces diploid cells.
37) How many bases are in the DNA molecule of a typical human chromosome?
D) Millions
57) Responsible for most of a muscle cell's ATP generation
D) Mitochondrion
51) Which of the following is NOT a valid difference between traditional and modern forms of biotechnology? A) Modern biotechnology can isolate and manipulate individual genes. B) Traditional biotechnology can produce cloned animals with new genes. C) Traditional biotechnology was based solely on selective breeding. D) Modern forms of biotechnology are slower than traditional forms of biotechnology.
D) Modern forms of biotechnology are slower than traditional forms of biotechnology.
69) Which of the following is NOT a theory of epigenetics explaining how cells can change gene function without changing the DNA base sequence? A) Modification of DNA B) Modification of chromosomal proteins C) Altering transcription and translation with noncoding RNA D) Mutations causing new beneficial alleles
D) Mutations causing new beneficial alleles
27) Which of the following is an example of an electron-carrier molecule?
D) NADH
61) In general, a substance that carries an electric charge can dissolve in water. Given this fact, which of the following would most likely NOT dissolve in water? A) Polar covalent molecules B) Ionic compounds C) NaCl D) Nonpolar molecules
D) Nonpolar molecules
74) Which of the following biological molecules are composed of monomer units containing a sugar, a phosphate group, and a nitrogen-containing base? A) Proteins B) Lipids C) Carbohydrates D) Nucleic acids
D) Nucleic acids
26) To be able to continue, each turn of the Krebs cycle must regenerate which of the following as a final product?
D) Oxaloacetate
27) The net movement of molecules from a high concentration to a low concentration is best described by which of the following? A) Endocytosis B) Active transport C) Osmosis D) Passive transport E) Exocytosis
D) Passive transport
62) Which process accounts for the movement of solid particles (such as food) into some animal cells? A) Active transport B) Facilitated diffusion C) Osmosis D) Phagocytosis E) Simple diffusion
D) Phagocytosis
65) Which of the following is a FALSE statement about prokaryotes? A) Prokaryotes have a plasma membrane, similar to that of eukaryotes. B) Prokaryotes may contain extra genes in plasmids. C) Prokaryotic cells contain ribosomes. D) Prokaryotes are so small that they can be seen only with a high-power electron microscope.
D) Prokaryotes are so small that they can be seen only with a high-power electron microscope.
21) How do prokaryotic and eukaryotic chromosomes differ?
D) Prokaryotic chromosomes are not contained in a membrane-bound organelle.
63) Your classmate is trying to keep all the facts about biological molecules straight. He asks you to explain how amino acids and proteins are related. What do you tell him? A) Amino acids are formed by joining together many proteins. B) Proteins are a portion of an amino acid. C) Proteins are chains of carbohydrates, and amino acids are a type of lipid. D) Proteins are made up of chains of amino acids.
D) Proteins are made up of chains of amino acids.
33) Which pair of enzymes is necessary to make recombinant DNA? A) Restriction enzyme and DNA polymerase B) DNA polymerase and DNA ligase C) DNA polymerase and RNA polymerase D) Restriction enzyme and DNA ligase
D) Restriction enzyme and DNA ligase
46) Which of the following can be used to detect genetic disorders? A) STRs only B) Restriction enzyme fragments only C) Arrays of DNA probes only D) Restriction enzyme fragments and DNA probe arrays only
D) Restriction enzyme fragments and DNA probe arrays only
half of the resulting progeny have red flowers, whereas the other half have white flowers. The genotype of the test-crossed parent was
D) Rr.
15) Which of the following is NOT associated with meiosis?
D) Somatic cells
53) In the 1990s, researchers attempted to improve the balance of amino acids in soybean protein by inserting a gene from Brazil nuts. Which of the following is the best reason as to why the transgenic soybeans have never been grown commercially? A) Regulatory hurdles made the modified soybeans too expensive to market profitably. B) The public was misinformed by food-safety advocates and refused to buy products made from the modified soybeans. C) The modified soybeans could not grow with the foreign gene present. D) Some people were allergic to the protein product of the Brazil nut gene.
D) Some people were allergic to the protein product of the Brazil nut gene.
17) Sulfur is an essential element in the human body, and studying its characteristics is important in 17) understanding human physiology. Sulfur atoms have six electrons in their outer shell. Based on this information, which of the following is TRUE? A) Sulfur is an important isotope of hydrogen. B) Sulfur is inert. C) Sulfur has eight electrons in its outer shell. D) Sulfur can form important molecules using covalent bonds.
D) Sulfur can form important molecules using covalent bonds.
84) Nuclear envelopes form during which phase of mitosis?
D) Telophase
85) During which phase of mitosis does cytokinesis occur?
D) Telophase
48) During which phase of the eukaryotic cell cycle do growth and nutrient acquisition occur?
D) The G1 phase of interphase
6) Imagine that you have been hired as a chemist and your first task is to examine a newly discovered 6) atom. The paperwork you are given states that its atomic number is 110. What does this mean? A) The atom contains 55 protons and 55 neutrons. B) The atom contains 55 electrons. C) The atom is an isotope. D) The atom contains 110 protons.
D) The atom contains 110 protons.
21) Which of the following best explains why a particular atom may not form compounds easily? 21) A) The atom has an uneven number of protons. B) The atom has seven electrons in its outer shell. C) The atom has no electrons. D) The atom's outer energy shells are completely full.
D) The atom's outer energy shells are completely full.
4) Phosphorus has an atomic number of 15, so what is the distribution of its electrons? A) The first, second, and third energy levels have 5 electrons each. B) The electron arrangement cannot be determined from the atomic number alone. C) The first energy level has 8 and the second has 7. D) The first energy level has 2, the second has 8, and the third has 5. E) The first energy level has 2 and the second has 13.
D) The first energy level has 2, the second has 8, and the third has 5.
44) An atom of nitrogen attracts electrons more strongly than an atom of hydrogen. In an ammonia molecule (NH3), which of the following best describes the electrical charge of the individual atoms? A) The nitrogen is slightly positive. B) The nitrogen becomes neutral. C) The hydrogens are strongly negative. D) The nitrogen is slightly more negative. E) Charges balance out and none of the atoms has any charge.
D) The nitrogen is slightly more negative.
57) What determines the function of the gene product?
D) The sequence of bases
48) A man who carries a harmful sex-linked (on the X chromosome) gene will pass the gene on to
D) all of his daughters.
79) In this scenario, how are the soap, dirt/oil, and water arranged at the molecular level? A) The soap is converted into a lipid that binds to the dirt/oil while repelling the water. B) The soap molecules encase the dirt/oil within a small droplet that has a hydrophobic exterior and a hydrophilic interior. C) Water and dirt/oil form covalent bonds inside a small droplet that has a soap -based outer membrane. D) The soap molecules encase the dirt/oil within a small droplet that has a hydrophilic exterior and a hydrophobic interior.
D) The soap molecules encase the dirt/oil within a small droplet that has a hydrophilic exterior and a hydrophobic interior.
78) In this scenario, what is the most likely procedure beer makers use to produce alcohol from starchy 97) grains? A) The starch is converted into glycogen, which is easier for the yeast to digest. B) The starch is converted into a polymer of many glucose molecules before being used. C) Water is used to break the bonds between glucose subunits in the starch, in a form of dehydration synthesis. D) The starch is broken down into mono- and/or disaccharides by hydrolysis before use.
D) The starch is broken down into mono- and/or disaccharides by hydrolysis before use.
43) Which of the following is TRUE about waxes? A) They are an important food source, and most animals have enzymes for breaking them down. B) They are a type of complex carbohydrate. C) They are unsaturated and most similar to proteins. D) They are saturated fats and are solid at normal outdoor temperatures.
D) They are saturated fats and are solid at normal outdoor temperatures.
43) Which of the following provides evidence that mitochondria and chloroplasts were once free-living prokaryotic organisms? A) They produce digestive enzymes on their rough ER. B) They contain nucleoids. C) They capture the energy of sunlight to make ATP. D) They contain their own DNA, independent of the nucleus.
D) They contain their own DNA, independent of the nucleus.
30) If sulfur has an atomic number of 16, how many covalent bonds can it form with other atoms? A) Four B) Six C) Zero D) Two E) Eight
D) Two
24) What is the anticodon for AUC? A) CUA B) AUC C) TAG D) UAG E) GAU
D) UAG
42) Suppose the template DNA strand of a "mini-gene" has the base sequence TACCCGGATTCA. The anticodon of the tRNA that carries the first amino acid to the ribosome will be A) AUG. B) UCA. C) UAC. D) UAG. E) AGU.
D) UAG
14) What structure in the membrane causes plasma membranes to resist freezing? A) Saturated fatty acid tails B) Channel proteins C) Nonpolar heads of the phospholipids D) Unsaturated fatty acid tails E) Cholesterol
D) Unsaturated fatty acid tails
57) Which type of molecule is most abundant in a typical cell? A) Carbohydrate B) Nucleic acids C) Lipid D) Water E) Protein
D) Water
44) Imagine an artificial cell made with a selectively permeable membrane that allows water to pass through but does not allow sugar to pass. If the artificial cell contains a 1% sugar solution and then you place the cell in a 2% sugar solution, what happens? A) There is no movement of water. B) Water enters the cell because the solution is hypotonic to the cell. C) Sugar diffuses in and water diffuses out until equilibrium is reached. D) Water leaves the cell because the solution is hypertonic to the cell.
D) Water leaves the cell because the solution is hypertonic to the cell.
28) The sex-determining chromosomes of a human male are the A) X and X chromosomes. B) Y and Y chromosomes. C) Z and Z chromosomes. D) X and Y chromosomes. E) Y and Z chromosomes.
D) X and Y chromosomes.
66) The fact that calico cats are only female supports the theory of A) two X chromosomes being required for coat color in cats. B) testosterone inactivation of Y-chromosome genes. C) mutations in all genes on one X chromosome. D) X-chromosome inactivation and Barr bodies in females.
D) X-chromosome inactivation and Barr bodies in females.
S = smooth, s = wrinkled)
D) YYSs
5) Four of the five answers listed below are haploid. Select the exception.
D) Zygote
57) For ice to melt, it has to A) increase its property of cohesion. B) increase its heat of vaporization. C) become less dense. D) absorb heat from its surroundings.
D) absorb heat from its surroundings.
24) A nucleolus is A) an extra nucleus in the cell. B) an area where the nucleus is synthesized. C) a membrane-bound organelle. D) an area in the nucleus of eukaryotic cells where ribosomes are synthesized and assembled. E) the area in a prokaryote where DNA is concentrated.
D) an area in the nucleus of eukaryotic cells where ribosomes are synthesized and assembled.
20) A Mendelian test cross is used to determine whether
D) an individual is homozygous or heterozygous.
41) Sister chromatids are separated from each other during
D) anaphase II.
71) The chromatids detach from one another and become visibly separate chromosomes during
D) anaphase.
14) The formation of sodium chloride (NaCl) is the result of A) chemical unreactivity. B) repelling between the same charges. C) covalent bonding. D) attraction between opposite charges.
D) attraction between opposite charges.
26) The use of bacteria to break down pollutants is referred to as A) nitrogen-fixation. B) biosynthesis. C) binary fission. D) bioremediation. E) biofixation.
D) bioremediation.
9) In dehydration synthesis, the atoms that make up a water molecule come from A) oxygen. B) enzymes. C) only one of the reactants. D) both of the reactants. E) carbohydrates.
D) both of the reactants.
25) Oil spills are sprayed with bacterial cultures in order to A) prevent the oil from sticking to wildlife. B) detoxify the oil. C) kill the bacteria. D) break down the oil. E) make the oil easier to wash away.
D) break down the oil.
22) Transfer RNA A) is a nucleic acid that carries the code for the primary structure of a protein. B) is a subunit of ribosomes. C) transfers proteins into the nucleus. D) brings amino acids to the ribosome.
D) brings amino acids to the ribosome.
68) The reason bread dough "rises" is due to the production of
D) carbon dioxide gas.
103) Growth factors stimulate
D) cells to divide.
33) When the DNA in a cell is uncoiled and spread throughout the nucleus, it is called
D) chromatin.
22) In prokaryotes, the DNA molecule is
D) circular.
40) In 2011, more than 85% of the ________ grown in the United States was transgenic. A) soybeans (only) B) cotton (only) C) corn and soybeans (only) D) corn, cotton, and soybeans E) corn (only)
D) corn, cotton, and soybeans
38) When genes are linked, a few of the recombinant genotypes still occur in the offspring because of
D) crossing over.
35) Restriction enzymes are useful in recombinant DNA studies because they A) join the cut ends of small DNA molecules. B) give plasmids antibiotic properties. C) can reproduce in bacteria. D) cut DNA only at specific locations. E) can separate pieces of DNA and RNA from each other.
D) cut DNA only at specific locations.
96) Cdks bind with ________, enabling the Cdks to function as enzymes.
D) cyclins
52) Imagine that a DNA sequence of 5'-A-C-G-T-A-C-G-T-3' is altered to 5'-A-C-G-A-C-G-T-3'. This could happen as a result of a(n) A) translocation. B) nucleotide substitution mutation. C) inversion. E) insertion mutation.
D) deletion mutation.
9) Radioactive isotopes are biological tools that are often used to 9) A) build up a store of calcium in a cell. B) increase the pH of blood. C) measure the size of fossils. D) detect brain tumors and other important medical technologies.
D) detect brain tumors and other important medical technologies.
14) Cells with two of each kind of chromosome are described by the term
D) diploid
5) Plasma membranes are best described as a A) double layer of phospholipids with hydrophilic heads facing away from one another. B) double layer of phospholipids with hydrophobic tails facing away from each other (toward the cytoplasm of the cell and the extracellular solution). C) single layer of phospholipids with water molecules attached along one side. D) double layer of phospholipids with hydrophobic tails facing toward one another. E) single layer of phospholipids with tails pointed toward the inside of the cell.
D) double layer of phospholipids with hydrophobic tails facing toward one another.
3) The "one-gene, one-enzyme" hypothesis concluded that A) specific enzymes give rise to specific genes. B) enzymes regulate gene activity. C) DNA is transcribed into RNA, which is translated into protein. D) each allele codes for a single type of protein. E) only certain genes function in cells.
D) each allele codes for a single type of protein.
57) A mutation that results in a change in the codon-reading pattern could result from A) a base substitution only. B) a base deletion only. C) a base insertion only. D) either an insertion or a deletion of a base.
D) either an insertion or a deletion of a base.
31) The part of the atom that has the greatest biological interest and interactions with other atoms is the A) proton. B) innermost electron shell. C) neutron. D) electron.
D) electron.
32) During the final events of cellular respiration, oxygen combines with ________ to form ________. A) energy-depleted electrons and carbon
D) energy-depleted electrons and hydrogen ions; water
49) The specific function of a protein is determined by the A) number of peptide bonds it contains. B) fatty acids that are joined together in the polypeptide. C) number of disulfide bonds. D) exact sequence of amino acids. E) hydrophilic head attached to the hydrophobic tail.
D) exact sequence of amino acids.
36) All of the following lipids or lipid components are hydrophobic EXCEPT A) unsaturated fats. B) waxes. C) fatty acid tails. D) fatty acid heads. E) saturated fats.
D) fatty acid heads.
7) Mobile prokaryotes can move around with the help of A) plasmids. B) endospores. C) sex pili. D) flagella. E) peptidoglycan.
D) flagella.
6) Phospholipids are A) made on the ribosomes. B) completely hydrophilic. C) completely hydrophobic. D) found in cell membranes.
D) found in cell membranes.
52) All of the following are polysaccharides EXCEPT A) chitin. B) glycogen. C) starch. D) glucose.
D) glucose.
21) Recognition proteins, such as those embedded on the surface of red blood cells, are composed of A) phospholipases. B) steroids. C) nucleic acids. D) glycoproteins.
D) glycoproteins.
60) A denatured protein differs from a normal protein because it A) contains many disulfide bonds. B) is composed of nucleotides. C) does not contain amino acids. D) has lost its usual secondary and tertiary structures.
D) has lost its usual secondary and tertiary structures.
2) Peas were a good organism of choice for Mendel because
D) he could study one trait at a time.
12) What would happen if the plasma membrane were composed solely of phospholipids and no proteins? A) All movement of molecules across the membrane would cease. B) Only water would be able to pass through the membrane. C) Immune reactions would not be affected. D) Simple diffusion and osmosis would continue to occur. E) The movement of molecules across the membrane would not be affected.
D) hydrophobic only.
9) Asexually produced daughter cells are
D) identical to each other and to the parental cell.
32) The term transfecting refers to A) making GMOs that are sterile. B) viral DNA becoming part of human DNA. C) making multiple copies of a small sample of DNA. D) inserting the gene of interest into the host organism.
D) inserting the gene of interest into the host organism.
13) Recombinant DNA technology A) involves only changing genes in large mammals. B) will never be of economic importance. C) randomly creates new genes from free nucleotides. D) involves combining existing genes from different organisms. E) is always dangerous and inevitably leads to mutations and mistakes.
D) involves combining existing genes from different organisms.
13) If a certain atom has a tendency to lose two electrons, that atom can then become a(n) A) polar molecule. B) water molecule. C) isotope. D) ion.
D) ion.
12) As a result of mitosis, each of your body cells
D) is genetically identical to all other body cells.
20) DNA moves within an electric field because it A) can possess different charges (positive or negative), depending on its base sequence. B) makes up chromosomes, which are slightly electromagnetic. C) is positively charged. D) is negatively charged.
D) is negatively charged.
25) A photograph of all the stained, prepared chromosomes in a eukaryotic cell is referred to as a
D) karyotype.
63) In human muscle cells, fermentation (by itself) produces
D) lactate.
29) If a cell contains large amounts of rough endoplasmic reticulum (ER), then A) digestive enzymes cannot be manufactured by that cell. B) few, if any, enzymes for biochemical processes are manufactured by that cell. C) membrane lipids could be produced by that cell. D) large amounts of protein hormones could be produced and exported by the cell. E) membrane proteins and phospholipids are lacking in the cell.
D) large amounts of protein hormones could be produced and exported by the cell.
2) The ________ portion of the cell membrane is responsible for the isolating function of the membrane, whereas the ________ portion regulates exchange and communication with the environment. A) cholesterol; lipid B) protein; cholesterol C) nucleic acid; lipid D) lipid; protein E) carbohydrate; lipid
D) lipid; protein
45) HDL and LDL are different types of cholesterol found in the blood. These compounds are A) carbohydrates. B) proteins. C) nucleic acids. D) lipids.
D) lipids.
62) Sickle-cell anemia is caused by a
D) recessive autosomal gene.
14) Which of the following has the fewest nucleotides in its strand? A) mRNA, having 100 bases B) Protein, with 2 polypeptides, each having 35 amino acids C) Protein, having 40 amino acids D) mRNA, having 75 nucleotides E) mRNA, having 50 codons
D) mRNA, having 75 nucleotides
1) Prions are known to cause A) sickle cell anemia. B) the common cold. C) herpes. D) mad cow disease.
D) mad cow disease.
17) PCR is essential for A) analyzing a person's fingerprints. B) allowing restriction enzymes to cut DNA. C) cutting DNA into many small pieces. D) making many copies of a small amount of DNA. E) creating recombinant plasmids.
D) making many copies of a small amount of DNA.
3) When a mouse cell and a human cell are fused, the membrane proteins of the two cells become uniformly distributed over the surface of the hybrid cell. This occurs because A) all proteins in the plasma membrane come from a membrane other than the human or the mouse. B) all proteins are anchored within the membrane. C) different membranes contain different proteins. D) many proteins can move around within the bilayer. E) proteins are asymmetrically distributed within the membrane.
D) many proteins can move around within the bilayer.
62) The chromosomes are aligned at the spindle equator during
D) metaphase.
3) The classification of bacteria has historically been based on A) the appearance of colonies and rate of growth. B) pigments and presence of flagella. C) nutrient requirements and pigments. D) microbial nutrition, physical appearance, and how they move. E) the means of locomotion and thickness of cell wall.
D) microbial nutrition, physical appearance, and how they move.
46) The organelle that extracts energy in food to produce ATP energy is the A) ribosome. B) cytoplasm. C) nucleus. D) mitochondrion. E) chloroplast.
D) mitochondrion
13) Flagellated cells can A) divide more quickly than nonflagellated cells. B) attach to surfaces more effectively because of the flagella. C) move internal organelles more efficiently than nonflagellated cells. D) move the cell through fluid.
D) move the cell through fluid.
34) A portion of a DNA molecule wound around a "bead" of histone protein is called a
D) nucleosome.
20) Under ideal conditions, the prokaryotic cell cycle can
D) occur in less than a half an hour.
38) A cell with a large number of lysosomes would most likely be very active in A) cell division. B) lipid synthesis. C) movement. D) phagocytosis.
D) phagocytosis.
10) A DNA nucleotide is made up of
D) phosphate-deoxyribose-base.
19) In bacteria, the small, circular pieces of DNA that are located outside the chromosome are called A) endospores. B) flagella. C) bacteriophages. D) plasmids. E) sex pili.
D) plasmids.
9) Small, accessory chromosomes found in bacteria that are useful in recombinant DNA procedures are called A) centrioles. B) viroids. C) bacteriophages. D) plasmids.
D) plasmids.
56) Human eye color is the result of
D) polygenic inheritance.
59) Human skin color is the result of
D) polygenic inheritance.
93) Movement of the chromosomes during anaphase would be most affected by a drug that
D) prevented shortening of microtubules.
36) Restriction enzymes A) separate the strands of DNA during PCR. B) can cut only bacterial DNA. C) randomly cut DNA into small pieces. D) produce single-stranded DNA fragments with "sticky ends."
D) produce single-stranded DNA fragments with "sticky ends."
35) Synapsis and crossing over occur during
D) prophase I.
47) Enzymes are specialized ________ that catalyze chemical reactions within the body. A) nucleic acids B) lipids C) carbohydrates D) proteins
D) proteins
46) The group of biological molecules that are most diverse in function is A) nucleic acids. B) carbohydrates. C) lipids. D) proteins.
D) proteins.
15) The genetic code is A) a set of two base sequences coding for each amino acid. B) used during the translation of DNA to mRNA. C) different in different organisms. D) read in sets of three bases called codons.
D) read in sets of three bases called codons.
47) A cell that lacks the ability to make DNA repair enzymes will
D) replicate its DNA as rapidly as a normal cell, but the resulting DNA will have more errors in it.
54) A random change in a DNA nucleotide base sequence A) is never beneficial to the organism. B) is never apparent in the organism. C) cannot have an influence on genetic variation. D) represents a mutation. E) always kills the cell.
D) represents a mutation.
39) Molecules that permeate a plasma membrane by facilitated diffusion A) do so much more quickly than those crossing by simple diffusion. B) require energy. C) move from an area of low concentration to an area of high concentration. D) require the aid of transport proteins.
D) require the aid of transport proteins.
2) The sequence of nitrogen-containing bases on one strand of DNA could determine all of the following EXCEPT the sequence of A) amino acids in a protein molecule. B) nitrogen-containing bases in the other DNA strand. C) nitrogen-containing bases in mRNA. D) ribose and phosphate molecules in tRNA.
D) ribose and phosphate molecules in tRNA.
27) It became apparent to Watson and Crick after completing their model that a DNA molecule could carry a vast amount of hereditary information in its A) variety of phosphate groups. B) different five-carbon sugars. C) side groups of bases. E) phosphate-sugar backbone.
D) sequence of bases.
24) Carbon has atomic number 6. Carbon most likely A) shares neutrons. B) loses electrons. C) shares protons. D) shares electrons. E) loses protons.
D) shares electrons.
38) All of the following may influence the rate of simple diffusion across a selectively permeable membrane EXCEPT the A) concentration gradient. B) size of the molecule. C) temperature. D) size of the cell. E) lipid solubility of the molecule.
D) size of the cell.
11) Plasmids are A) chromosomal loops made of RNA. B) necessary for bacteria to reproduce. C) noncircular DNA segments found only in bacteria. D) small, replicating rings of DNA found in bacteria. E) found only in three species of bacteria.
D) small, replicating rings of DNA found in bacteria.
30) Cells that primarily produce steroid hormones, such as testosterone and estrogen, have large quantities of A) plasma membranes. B) DNA. C) enzymes. D) smooth endoplasmic reticulum. E) cytoplasmic ribosomes.
D) smooth endoplasmic reticulum.
51) As a bicyclist pedals up a hill to the finish line of a race and "feels the burn" in his leg muscles, those muscle cells are most likely utilizing
D) some lactate fermentation and lactic starting to build up in his muscle tissue causing a cramp.
18) Cyanobacteria obtain energy from A) digesting benzene. B) digesting cyanide. C) parasitizing viruses. D) sunlight. E) digesting plants.
D) sunlight.
35) In eukaryotes, a promoter that signals the beginning of the gene and binds with the promoter typically consists of A) both DNA and RNA. B) rRNA and tRNA. C) the base sequence AUG and transcription factor binding sites. D) the bases TATAAA and response elements.
D) the bases TATAAA and response elements.
63) Gene expression is a term that relates to A) DNA replication. B) how genes are passed from parent to offspring. C) the karyotype of a chromosome set. D) the flow of genetic information from DNA to proteins. E) the unique set of genes in an individual.
D) the flow of genetic information from DNA to proteins.
20) During cellular respiration, the pyruvate produced in glycolysis is
D) the source of electrons for NADH and FADH2.
18) During the glucose activation stage of glycolysis
D) two ATP molecules are used to make one fructose bisphosphate molecule.
8) The earliest examples of biotechnology included the A) careful examination of patterns of bacterial inheritance. B) use of genetic markers to learn more about genetic inheritance. C) study and treatment of genetic diseases in people. D) use of selective breeding to provide better, more nutritious food.
D) use of selective breeding to provide better, more nutritious food.
69) Which disorder is characterized by the individual having a normal number of sex chromosomes?
E) Down syndrome
33) The Golgi apparatus packages materials into ________ for transport or export. A) plastids B) vacuoles C) organelles D) vesicles E) nucleoli
D) vesicles
51) Avocado sunblotch is caused by a A) bacterium. B) prion. C) virus. D) viroid. E) fungus.
D) viroid.
7) A recessive allele is one
D) whose effect is masked when paired with a dominant allele.
63) When gametes fuse during fertilization, a(n) ________ is produced.
D) zygote
8) Carbon-14 is often used for carbon dating, where scientists measure the rate of carbon-14 decay to 8) determine the age of items. Carbon-14 contains six protons and eight neutrons. During the process of carbon-14 decay, one of its eight neutrons becomes a proton and an electron is emitted. Which of the following is the best explanation of what has occurred? A) The resulting atom is still carbon-14. B) An ionic bond has formed. C) The resulting atom has a more stable nucleus. D) The resulting atom is now a different element because the number of protons has changed.
D)The resulting atom is now a different element because the number of protons has changed.
A shortage of phosphorus in the soil would make it especially difficult for a plant to manufacture _____. (eText Concept 5.5) * proteins * DNA * sucrose * cellulose * fatty acids
DNA
Choose the correct pathway of information flow in the cell.
DNA --> RNA --> protein
When a protein is denatured, why does it lose its functionality? (eText Concept 5.4) * Denaturation destroys the primary structure of the protein, and the protein breaks down to monomers. * Different amino acids are substituted into the sequence, so the protein's properties change. * Denaturation breaks the weak bonds, such as hydrogen bonds and van der Waals interactions, that hold the protein in its three-dimensional shape. Without the proper shape, the protein cannot function. * Denaturation breaks the covalent bonds that hold the protein in its three-dimensional shape. Without the proper shape, the protein cannot function. * The protein's pH changes, causing it to lose its functionality.
Denaturation breaks the weak bonds, such as hydrogen bonds and van der Waals interactions, that hold the protein in its three-dimensional shape. Without the proper shape, the protein cannot function.
What would happen if the plasma membrane were composed solely of phospholipids and no proteins?
Diffusion and osmosis would continue to occur.
14) Imagine that 1 milliliter of an experimental drug diluted in a saline solution is injected into 20 14) pregnant mice to determine possible side effects. Which of the following is a suitable control for this experiment? A) 20 pregnant mice injected with 2 milliliters of the drug B) 20 non-pregnant mice injected with 1 milliliter of the drug C) 20 male mice injected with 1 milliliter of saline D) 20 male mice injected with 1 milliliter of the drug E) 20 pregnant mice injected with 1 milliliter of saline
E
16) Which of the following is TRUE regarding faith-based beliefs and scientific theories? 16) A) Faith-based beliefs can become scientific theories. B) Scientific theories are not modifiable but faith-based beliefs are. C) Both faith-based beliefs and scientific theories can be proven. D) Any and all faith-based beliefs can be disproven but scientific theories cannot. E) Any and all scientific theories can be disproven but faith-based beliefs cannot.
E
31) All of the following are examples of adaptations EXCEPT A) larger teeth in beavers for gnawing wood. B) different beak shapes for birds that eat seeds or insects. C) flower coloration that attracts pollinators. D) insects that resemble twigs. E) mice learning a maze to get food.
E
46) Hemophilia is a sex-linked recessive gene that causes a blood disorder. What are the chances that the daughter of a normal man and a heterozygous woman will have hemophilia?
E) 0%
76) Some people trying to lose weight have gone on the Atkins diet, in which they eat mostly high-protein, low-carbohydrate foods such as meat, cheese, and eggs. The amino acids in these protein-rich diets, such as alanine, glycine, and serine, can be converted to pyruvate by deamination (removal of the amino group). Based on this scenario as well as your knowledge of cellular respiration, how many ATP, NADH, and FADH2 molecules will be generated from one molecule of alanine during the mitochondrial matrix reactions? Hint: Only consider the reactions from the point at which the alanine carbons enter cellular respiration.
E) 1 FADH2, 4 NADH, and 1 ATP
43) The human genome contains about ________ genes. A) 1 million B) 1 billion C) 100 D) 1,800 E) 20,000 to 25,000
E) 20,000 to 25,000
29) If two parents are carriers of albinism (an autosomal recessive trait), what is the chance that their fourth child will have a homozygous dominant genotype?
E) 25%
34) If you cross pea plants that are both heterozygous for purple flowers and yellow seeds (PpYy), and you examine 800 offspring for flower and seed color, about how many do you expect to have white flowers and green seeds?
E) 50
51) A type of muscular dystrophy shows sex-linked recessive inheritance. Affected persons usually die by the age of 20. Suppose that a boy with the disease lives long enough to marry a woman heterozygous for the trait. If they have a son, what is the probability that he will have the disease?
E) 50%
46) Which of the following organisms does NOT reproduce its cells by mitosis and cytokinesis?
E) A bacterium
6) Which of the following is within the size range of a typical prokaryote? A) A cell 700 micrometers long B) A cell 100 micrometers in diameter C) A cell the size of the period at the end of a sentence D) A cell 25 micrometers in diameter E) A cell 2 micrometers in diameter
E) A cell 2 micrometers in diameter
37) If ATP is made in the mitochondria, how does it provide energy for reactions in the cytoplasm of the cell?
E) ATP diffuses into the cytoplasm through large pores in the outer membrane of the mitochondria out.
5) In which of these environments would you normally find prokaryotes? A) Human skin B) A spoonful of soil C) A single drop of seawater D) An animal's intestinal tract E) All of the above
E) All of the above
10) Homologous chromosomes
E) All of the choices are correct.
37) Crossing over A) alters the composition of chromosomes and results in new combinations of alleles being channeled into the daughter cells. B) generally results in synapsis and binary fission. C) involves breakages and exchanges between sister chromatids. D) involves nucleoli. E) All of the choices are correct.
E) All of the choices are correct.
56) Crossing over is one of the most important events in meiosis because A) homologous chromosomes must be separated into different daughter cells. B) it produces new arrays of alleles on chromosomes. C) the number of chromosomes allotted to each daughter cell must be halved. D) homologous chromatids must be separated into different daughter cells. E) All of the choices are correct.
E) All of the choices are correct.
61) A "mini-gene" has the base sequence TACCCGTGCACG. If the T at the beginning of the sequence is deleted, what will be the consequence? A) Only the amino acid coded for in that codon will be changed. B) RNA polymerase will skip that codon, but all the others will be read normally. C) RNA polymerase will correct the deletion, and a normal protein will be produced. D) The first nucleotide is always replaced anyway, so there will be no change. E) All of the codons after that point will be changed.
E) All of the codons after that point will be changed.
3) Which of the following is NOT a use for biotechnology? A) Altering food plants to increase yields B) Producing large quantities of particular human proteins C) Producing effective and safe vaccines D) Identifying human fetuses with particular genetic diseases E) Altering the intelligence levels of newborn infants
E) Altering the intelligence levels of newborn infants
13) Which kind of metabolic poison would interfere with the glycolysis stage of cellular respiration?
E) An agent that closely mimics the structure of glucose but is not capable of being metabolized and broken down
34) The corkscrew-shaped bacterium ________ is vectored by ticks into humans and eventually may cause nervous system issues. A) Yersinia pestis B) Clostridium tetani C) Clostridium botulium D) Escherichia coli E) Borrelia burgdorferi
E) Borrelia burgdorferi
41) Which of the following applications of biotechnology results in an insect-resistant plant? A) Insulin production by bacteria B) Growth-hormone-treated cows C) Banana-based vaccine against pathogenic Escherichia coli D) Herbicide-resistant corn E) Bt toxin production by soybeans
E) Bt toxin production by soybeans
51) A peptide bond forms between which of these groups? A) Hydroxyl and carboxyl B) Carboxyl and aldehyde C) Amino and aldehyde D) Phosphate and hydroxyl E) Carboxyl and amino
E) Carboxyl and amino
48) Which of the following relationships is FALSE? A) Mitochondria-formation of ATP B) Cell wall-support and protection C) Nucleus-genetic information D) Ribosomes-site of protein synthesis E) Chloroplasts-chief site of lipid synthesis
E) Chloroplasts-chief site of lipid synthesis
49) Which of the following events does NOT occur in prophase II but does occur in prophase I?
E) Crossing over and synapsis only
24) Specific fragments of DNA on a gel can be visualized using A) STRs. B) PCR. C) electrophoresis. D) restriction enzymes. E) DNA probes.
E) DNA probes.
13) By the early 1950s, many biologists realized that the key to understanding inheritance lay in the structure of
E) DNA.
8) Which of the following best summarizes the relationship between dehydration reactions and hydrolysis? A) Dehydration reactions can occur only after hydrolysis. B) Hydrolysis creates monomers, and dehydration reactions destroy them. C) Hydrolysis creates polysaccharides, and dehydration creates monosaccharides. D) Dehydration reactions occur only in animals, and hydrolysis reactions occur only in plants. E) Dehydration reactions assemble polymers, and hydrolysis breaks them down.
E) Dehydration reactions assemble polymers, and hydrolysis breaks them down.
33) Regarding the structure of DNA, which of the following is covalently bonded to a nitrogen base?
E) Deoxyribose
67) Which disorder is characterized by an abnormal number of autosomes?
E) Down syndrome
68) For which disorder can those affected be male or female?
E) Down syndrome
12) Which structure enables a bacterium to survive and infect a host even after a long period of desiccation? A) Pili B) Capsule C) Slime layer D) Protein coat E) Endospore
E) Endospore
38) Which of the following most closely matches the correct order of the main events of aerobic cellular respiration?
E) Glycolysis, Krebs cycle, ETC, major ATP production
42) Which of the following is the proper sequence for mitosis (I. metaphase, II. telophase, III. prophase, IV. anaphase)?
E) III, I, IV, II
48) Which of the following involves the use of human genes? A) Genetically altered soybean oils B) Herbicide-resistant corn C) Bt toxin production by soybeans D) Banana-based vaccine against pathogenic E. coli E) Insulin production by bacteria
E) Insulin production by bacteria
19) Where is glycogen stored in vertebrate animals? A) Teeth and bones B) Fat cells C) Pancreas and blood D) Brain and kidneys E) Liver and muscles
E) Liver and muscles
36) Which of the following parts of the mitochondria is (are) directly involved in the synthesis of ATP during chemiosmosis?
E) Matrix and inner membrane
23) Which organelle is most abundant in cardiac muscle cells? A) Plastids B) Lysosomes C) Golgi complexes D) Smooth ER E) Mitochondria
E) Mitochondria
36) Hydrogen bonding can take place between a hydrogen atom and what other atom? A) Nitrogen B) Nitrogen, oxygen, and fluorine C) Fluorine D) Hydrogen E) Oxygen
E) Oxygen
50) Which of the following is a protein made up of amino acids? A) Transfer RNA B) Messenger RNA C) Uracil D) DNA E) RNA polymerase
E) RNA polymerase
18) What prevents your immune system from attacking your own cells? A) Cholesterol B) Inadequate enzymes C) Receptor proteins D) Fever E) Recognition proteins
E) Recognition proteins
5) Which of the following results from inserting foreign DNA into an organism to produce a new gene combination? A) Gene cloning B) Mutations C) Translation D) Regulatory genes E) Recombinant DNA
E) Recombinant DNA
59) The bonding of two amino acid molecules to form a larger molecule requires which of the following? A) Both removal of a water molecule and formation of a hydrogen bond B) Formation of a hydrogen bond C) Formation of a glycosidic bond D) Addition of a water molecule E) Removal of a water molecule
E) Removal of a water molecule
7) Four of the five answers listed below are characteristic of meiosis. Select the exception.
E) Results in producing genetically identical cells
55) Site of protein synthesis
E) Rough endoplasmic reticulum
10) What do the sticky layers of protective slime produced by some bacteria enable them to do? A) Move from one location to another B) Sexually reproduce C) Survive extreme conditions for long periods of time D) Acquire resistance to antibiotics E) Stick together and form biofilms
E) Stick together and form biofilms
62) A "mini-gene" has the base sequence TACCCGTGCACG. Which of the following sequences represents a single base substitution? A) TACCCGTGCACG B) TACCCGTGTCACG C) TACCGTGCTACG D) TACCCGGCACG E) TACCCGAGCACG
E) TACCCGAGCACG
46) Which of the following is TRUE about the accuracy of DNA replication?
E) The few errors made by DNA polymerase are usually corrected by repair enzymes.
36) Imagine that you self-pollinate heterozygous purple-flowered, long-pollened pea plants and get mostly purple-flowered, long-pollened plants and white-flowered, short-pollened plants, with a few purple-flowered, short-pollened or white-flowered, long-pollened plants. What is the most likely explanation?
E) The genes for flower color and pollen length are linked.
32) Imagine that you fill a shallow tray with water and place a drop of red ink in one end of the tray and a drop of green ink in the other end. Which of the following is TRUE at equilibrium? A) The red and green ink do not mix at all. B) The concentration of each ink is higher at one end of the tray than at the other end. C) No predictions can be made without knowing the size of the ink molecules. D) The red ink is uniformly distributed in one half of the tray, and the green ink is uniformly distributed in the other half of the tray. E) The red and green inks are both uniformly distributed throughout the tray.
E) The red and green inks are both uniformly distributed throughout the tray.
15) Within the fluid mosaic of a plasma membrane, what is the role of transport and channel proteins? A) They identify the cell. B) They may set off cellular changes such as cell division or hormone secretion. C) They prevent the passage of amino acids. D) They are cell-surface connection sites. E) They permit ions and water molecules to move through the plasma membrane.
E) They permit ions and water molecules to move through the plasma membrane.
48) Which of the following attaches to specific amino acids? A) DNA B) Messenger RNA C) Ribosomal RNA D) RNA polymerase E) Transfer RNA
E) Transfer RNA
31) Which of the following is the dreaded "black death" bacterium? A) Streptococcus B) Clostridium C) Borrelia burgdorferi D) Escherichia coli E) Yersinia pestis
E) Yersinia pestis
7) All cells possess all of the following components EXCEPT A) cytoplasm. B) genetic material (DNA or RNA). C) ribosomes. D) a plasma cell membrane. E) a nuclear membrane.
E) a nuclear membrane.
65) Restriction enzymes are "restricted" in the sense that they normally work on only bacterial DNA.
FALSE
58) The diploid number of chromosomes in mammals is always
E) an even number.
70) In meiosis, sister chromatids separate during
E) anaphase II.
64) The chromosomes are moving to opposite poles during
E) anaphase.
60) Active transport requires all of the following EXCEPT A) ATP. B) a membrane. C) transport proteins. D) a gradient. E) aquaporins.
E) aquaporins.
45) Viroids A) have a plasma membrane. B) are infectious chains of amino acids. C) attack bacteria. D) are infectious pieces of DNA enclosed in a protein coat. E) are infectious pieces of RNA.
E) are infectious pieces of RNA.
39) Chromatids are
E) attached at their centromeres and are identical until crossing over occurs.
9) In biological membranes, the phospholipids are arranged in a A) single layer, with the phosphorus-containing region facing the interior of the cell. B) bilayer, with the fatty acids facing outward (facing the interior and exterior of the cell). C) bilayer, with the phosphorus groups in the interior of the membrane. D) single layer, with the fatty acids facing the interior of the cell. E) bilayer, with the fatty acids pointing toward one another.
E) bilayer, with the fatty acids pointing toward one another.
17) The fiber in your diet is actually A) protein. B) starch. C) glycogen. D) ATP. E) cellulose.
E) cellulose.
33) Carbon dioxide crosses the plasma membrane by simple diffusion. The rate at which carbon dioxide enters the cell is determined by the A) amount of energy being produced by the cell. B) amount of oxygen being exported from the cell. C) amount of carbon dioxide outside of the cell. D) amount of transport protein in the membrane. E) concentration of carbon dioxide on each side of the membrane.
E) concentration of carbon dioxide on each side of the membrane.
16) Most biological molecules are joined by A) hydrogen bonds. B) peptide bonds. C) disulfide bonds. D) ionic bonds. E) covalent bonds.
E) covalent bonds.
49) All of the following eukaryotes can reproduce asexually EXCEPT
E) domestic dogs.
32) Watson and Crick are credited with the discovery and description of the DNA
E) double helix.
14) Sex pili are prokaryotic structures that are used A) for movement. B) during binary fission. C) for adhering to surfaces. D) for gathering prey. E) during conjugation.
E) during conjugation.
42) All of the following are benefits of sequencing the human genome EXCEPT A) better comparisons can be made between human genetics and the genetics of other organisms. B) genes were discovered whose functions were previously unknown. C) more genes that cause disease have been discovered. D) the number of genetic disorders that can be diagnosed with molecular techniques has increased. E) every genetic disorder is now curable or preventable.
E) every genetic disorder is now curable or preventable.
10) The hydrophilic regions of a membrane protein are most likely to be found A) associated with the fatty acid region of the lipids. B) only in muscle cell membranes. C) attached to carbohydrates and facing the interior of a cell. D) in the interior of the membrane. E) exposed on the surface of the cell membrane.
E) exposed on the surface of the cell membrane.
2) The anaerobic breakdown of glucose is called
E) fermentation.
66) Prokaryotic cells do not have mitochondria, so they cannot make ATP energy.
FALSE
67) All bacteria are harmful to humans.
FALSE
55) Water molecules are cohesive because they A) make up 60% to 90% of an organism's body weight. B) contain protons. C) are repelled by nonpolar molecules. D) stick to other polar molecules. E) form hydrogen bonds.
E) form hydrogen bonds.
68) The electrical signal for a muscle to contract passes rapidly from one cell to the next via A) internal proteins. B) desmosomes. C) plasmodesmata. D) tight junctions. E) gap junctions.
E) gap junctions.
16) In biotechnology research, DNA fragments created by restriction enzyme action are separated from one another via A) PCR. B) crossing over. C) centrifugation. D) filtering. E) gel electrophoresis.
E) gel electrophoresis.
18) The genetic makeup of an individual is the
E) genotype.
36) Proteins that resemble beads on which DNA molecules are wound are called
E) histones.
46) Prions are A) bacterial proteins. B) sexually transmitted bacteria. C) viral protein coats. D) also known as viroids. E) improperly folded proteins.
E) improperly folded proteins.
86) One difference between mitotic cell division in animal cells and plant cells is that
E) in plant cells, cytokinesis occurs as vesicles deposit carbohydrates along the equator.
3) If glucose is metabolized under completely anaerobic conditions, pyruvate
E) is converted by fermentation to lactate or CO2 + ethanol.
57) After fermentation in human cells, lactate is converted to pyruvate in the
E) muscles.
11) Suppose that plasma membranes were single layers of phospholipids rather than double layers, and the heads faced the extracellular fluid. The interior of this hypothetical cell would have to be A) hydrophobic and nonpolar. B) hydrophilic only. C) polar only. D) hydrophobic only. E) nonpolar only.
E) nonpolar only.
79) In the fungus Neurospora, a metabolic pathway synthesizes the amino acid Z (which is essential for its survival) from the precursor W. The intermediates X and Y are also produced in this pathway. The enzymes E1, E2, and E3 catalyze three reactions in the process, as follows: E1 E2 E3 W → X → Y → Z X-ray radiation can be used to create a mutant strain of Neurospora that has a defective gene sequence for E2. Based on this scenario, the mutant strain will survive on media that contain A) only X. B) only Z. C) W, X, Y, or Z. D) only W or X. E) only Y or Z.
E) only Y or Z.
5) According to the law of segregation
E) pairs of alleles on homologous chromosomes separate during the formation of gametes.
10) The physical manifestation of an organism's genes is its
E) phenotype.
19) The main lipids found in cell membranes are A) triglycerides. B) steroids. C) glycerol. D) waxes. E) phospholipids.
E) phospholipids.
72) You observe a cell under a microscope and you can clearly see a cell wall, a vacuole, and cytoplasmic connections. These cytoplasmic connections must be A) gap junctions. B) tight junctions. C) osmotic channels. D) desmosomes. E) plasmodesmata.
E) plasmodesmata.
35) The hydrogen bond between two water molecules forms because water is A) nonpolar. B) a large molecule. C) hydrophobic. D) a small molecule. E) polar.
E) polar.
47) Major gene reshuffling takes place during
E) prophase I.
59) The spindle apparatus begins to become visible during
E) prophase.
53) Hydrophilic molecules A) are repelled by water. B) do not readily dissolve in water. C) are neutral and nonpolar. D) form hydrogen bonds among themselves. E) readily dissolve in water.
E) readily dissolve in water.
24) Crossing smooth-seeded pea plants with wrinkled-seeded pea plants resulted in progeny that all had smooth seeds. This indicates that the wrinkled-seed trait is
E) recessive only.
68) DNA carries genetic information in its A) helical form. B) tertiary structure. C) phosphate groups. D) sugar groups. E) sequence of bases.
E) sequence of bases.
21) PCR enables scientists to do all of the following EXCEPT A) make gene copies quite cheaply. B) make gene copies very rapidly. C) use a very small amount of DNA as starting material. D) make billions of copies of a particular gene. E) sequence the bases within a gene as it is being copied.
E) sequence the bases within a gene as it is being copied.
34) During meiosis II
E) sister chromatids of each chromosome are separated from each other.
20) All the following are important functions of the cytoskeleton EXCEPT A) maintenance of shape. B) maintenance of organization in the cell. C) movement of organelles. D) assistance during cell division. E) storage of food molecules.
E) storage of food molecules.
67) The "backbone" of a nucleic acid molecule is made of A) NAD+ and FAD. B) amino acids. C) lipids. D) ATP molecules. E) sugar and phosphate groups.
E) sugar and phosphate groups.
17) Some bacteria use H2S instead of H2O in photosynthesis, and they release A) acetic acid. B) ethanol. C) oxygen. D) carbon monoxide. E) sulfur.
E) sulfur.
30) Transcription is the process of A) assembling an RNA molecule without a template. B) synthesizing a protein using information from mRNA. C) synthesizing a DNA molecule from an RNA template. D) replicating a single-stranded DNA molecule. E) synthesizing an RNA molecule using a DNA template.
E) synthesizing an RNA molecule using a DNA template.
30) The terminal ends or "tips" of a chromosome are called
E) telomeres.
70) The chromosomes have arrived at opposite poles during
E) telophase.
3) If meiosis did NOT occur in sexually reproducing organisms
E) the chromosome number would double in each generation.
44) Traits controlled by sex-linked recessive genes are expressed more often in males because
E) the male has only one gene for the trait.
50) Controversy has arisen about using genetically engineered bovine growth hormone to increase milk yield in cattle. The lesson gained from this controversy is that A) society should let scientists decide the proper uses of recombinant DNA technology. B) recombinant DNA technology is inherently a bad idea and should be abandoned. C) humans are not wise enough to use this technique properly. D) citizens should not be allowed to decide such issues, as they tend to make decisions based on emotion. E) the whole human society should decide the proper uses of recombinant DNA technology.
E) the whole human society should decide the proper uses of recombinant DNA technology.
32) Fats and oils are made of A) two fatty acids and one carboxyl acid. B) three amino acids and one glycerol. C) one glycogen and two phospholipids. D) three glycerols and three fatty acids. E) three fatty acids and one glycerol.
E) three fatty acids and one glycerol.
37) The process of converting the "message" of mRNA into a sequence of amino acids is called A) replication. B) transcription. C) activation. D) repression. E) translation.
E) translation.
56) During the fermentation of one molecule of glucose, the net production of ATP is
E) two molecules
41) A plant cell adapted for waste storage would probably contain a large number of A) ER. B) mitochondria. C) ribosomes. D) nuclei. E) vacuoles.
E) vacuoles.
In terms of cellular function, what is the most important difference between prokaryotic and eukaryotic cells? (eText Concept 6.2) * Eukaryotic cells can synthesize proteins but prokaryotic cells cannot. * Eukaryotic cells are much more successful than prokaryotic cells. * Eukaryotic cells lack many of the organelles found in prokaryotes. * Eukaryotic cells are compartmentalized, which allows for specialization. * Eukaryotic cells are larger than prokaryotic cells.
Eukaryotic cells are compartmentalized, which allows for specialization.
111) Eukaryotic chromosomes are made up of only DNA.
FALSE
57) Bacteria are multicellular microbes.
FALSE
58) Bacteria are able to increase their genetic variability by reproducing sexually.
FALSE
59) Bacterial endospores are easily damaged by heat and drying.
FALSE
60) Biofilms are the immune system's way to keep pathogens from colonizing a host.
FALSE
61) A recombinant plasmid contains only human and bacterial DNA.
FALSE
62) Anaerobic bacteria require high levels of oxygen to survive.
FALSE
62) Chargaff found that the amounts of the four bases vary from species to species, but the amount of adenine always equals the amount of guanine and the amount of thymine always equals the amount of cytosine.
FALSE
62) PCR joins many small DNA molecules into a long chain.
FALSE
62) Scientific theories are the same in any part of the world (meaning they do not vary by location).
FALSE
63) Individuals within the same species have the same DNA "fingerprint," but individuals from different species have different DNA fingerprints.
FALSE
63) Nitrogen-fixing bacteria remove nitrogen from plants and return it to the soil.
FALSE
64) A good experiment should include as many variables as possible at the same time.
FALSE
64) The number of subunits in a DNA molecule is more important to its function than the sequence of these subunits.
FALSE
65) A hypothesis is typically stated as an "If . . . then" statement.
FALSE
65) Bioremediation is the process in which bacteria digest plants and release oily toxins.
FALSE
67) In semiconservative replication, a DNA molecule serves as a template for a new DNA molecule, which consists of either both parental strands of DNA or both newly synthesized strands of DNA.
FALSE
68) DNA helicase is involved in "rewinding" the strands of DNA back into a helix after replication.
FALSE
68) Isotopes are atoms of the same element that have different numbers of protons.
FALSE
68) The DNA of humans and chimps differs by about 10%.
FALSE
68) Viruses contain both DNA and RNA.
FALSE
69) About 90% of the human genome contains the genes.
FALSE
70) DNA replication occurs without errors due to the complementary base pairing used in the copying process.
FALSE
70) Kuru is caused by one of the archaea.
FALSE
70) Prokaryotic cells have a true nucleus and eukaryotic cells do not.
FALSE
71) Because viruses have limited genetic material, their mutation rates are very low.
FALSE
71) Biodiversity is the total number of organisms in an ecosystem.
FALSE
71) Stringent safety rules are not necessary for recombinant DNA research because it is a natural process that occurs in the absence of human intervention.
FALSE
71) The attractive force that holds two or more water molecules together is an example of an ionic bond.
FALSE
72) Inversions are movements of DNA from one chromosome to another.
FALSE
72) Smallpox is caused by infected rats.
FALSE
73) Carrier molecules in the plasma membrane are required only for active transport.
FALSE
73) Glycolysis and the Krebs cycle reactions both occur in the mitochondria.
FALSE
75) After a dye diffuses uniformly throughout a glass of water, the dye molecules are no longer
FALSE
75) Each ribosome is specific for a particular type of protein.
FALSE
75) Most liquids become less dense upon solidification, but water is different in that it becomes denser when it solidifies.
FALSE
75) The process of fermentation is energetically more efficient than that of cellular respiration.
FALSE
76) tRNA is necessary for transcription to occur.
FALSE
77) Phospholipids have hydrophilic tail regions and hydrophobic head regions.
FALSE
78) Sister chromatids are also referred to as homologues or homologous chromosomes.
FALSE
78) The Barr body is the X chromosome in the cell that is expressed, whereas the other X chromosome is inactivated.
FALSE
79) Only males can express sex-linked traits.
FALSE
80) Crossing over takes place between sister chromatids during prophase I of meiosis I.
FALSE
80) Females always inherit sex-linked traits from their mothers.
FALSE
81) Sex-linked traits affect only sexual characteristics.
FALSE
82) Human females who receive sex-linked genes always express them.
FALSE
Which of these statements describes some aspect of facilitated diffusion? (eText Concept 7.3) * Facilitated diffusion of solutes may occur through channel or transport proteins in the membrane. * Facilitated diffusion of solutes occurs through phospholipid pores in the membrane. * Facilitated diffusion requires energy to drive a concentration gradient. * There is only one kind of protein pore for facilitated diffusion. * Facilitated diffusion is another name for osmosis.
Facilitated diffusion of solutes may occur through channel or transport proteins in the membrane. No. Facilitated diffusion occurs through integral membrane transport proteins.
Which of the following is false in regard to facilitated diffusion? (eText Concept 7.3) * Facilitated diffusion requires the hydrolysis of ATP. * Facilitated diffusion requires a concentration gradient. * Facilitated diffusion can occur using transport proteins. * Facilitated diffusion can move ions across membranes. * Facilitated diffusion can occur through protein channels.
Facilitated diffusion requires the hydrolysis of ATP.
More than half a century ago, two cell biologist published details of their research involving isolated membrane vesicle from chloroplasts. Normally, the fluid inside these vesicle is near neutral. In an experiment, these membrane vesicles were soaked in an acidic solution (pH 4) until the inside of the vesicle also became pH 4.
Facilitated diffusion, hydrogen ions moved into the vesicle through a channel.
What is the difference between "free" and "attached" ribosomes?
Free ribosomes occur in the cytoplasm, whereas attached ribosomes are found on the endoplasmic reticulum.
Researchers have been able to study the pathway of a secreted protein by "tagging" it with a fluorescent marker. Using this method, you would observe fluorescent moving from ER to which organelle?
Golgi apparatus
Sorts proteins and sends them to their proper destination
Golgi apparatus
Which cellular organelle packages enzymes and forms lysosomes?
Golgi apparatus
A researcher made an interesting observation about a protein made by the rough endoplasmic reticulum and eventually found in a cell's plasma membrane. The protein in the plasma membrane was actually slightly different from the protein made in the ER. The protein was probably altered in the _____. (eText Concept 6.4) rough endoplasmic reticulum transport vesicles plasma membrane smooth endoplasmic reticulum Golgi apparatus
Golgi apparatus No. The protein was originally synthesized on ribosomes of the rough ER, but modification occurs elsewhere.
Which of the following sequences represents the order in which a protein made in the rough endoplasmic reticulum might move through the endomembrane system? (eText Concept 6.4) * nuclear envelope#&8594;lysosome * Golgi apparatus#&8594;lysosome * lysosome#&8594;plasma membrane * plasma membrane#&8594;nuclear envelope * Golgi apparatus#&8594;mitochondria
Golgi apparatus#&8594;lysosome
The discomfort associated with irritable bowel syndrome can be alleviated with low doses of the class of antidepressants that block the reuptake of serotonin from the synaptic cleft (the space between adjacent neurons). Serotonin is a relatively small polar neurotransmitter used to transmit nerve impulses in the nerve tissue in the gut and central nervous system. Serotonin is transported back into the releasing neuron up its concentration gradient and down a sodium gradient. How might an antidepressant block serotonin reuptake by the releasing neuron? (eText Concept 7.4) * It could promote exocytosis of serotonin. * It could block active transport of serotonin back into the cell by blocking a serotonin-sodium symporter. * It could block receptor-mediated endocytosis. * It could block a cotransporter involved in facilitated diffusion * It could block the passive diffusion of serotonin back into the cell by chemically modifying serotonin.
It could block active transport of serotonin back into the cell by blocking a serotonin-sodium symporter.
Which of the following statements about diffusion is true? (eText Concept 7.3) * It always requires integral proteins of the cell membrane. * It requires expenditure of energy by the cell. * It is a passive process. * It occurs when molecules move from a region of lower concentration to a region of higher concentration. * It is very rapid over long distances.
It is a passive process.
Digests damaged organelles
Lysosome
How does a cell rid itself of defective or malfunctioning organelles?
Lysosomes assist in the removal of defective organelles by digesting them.
Which of the following statements concerning carbohydrates associated with the plasma membrane is correct? (eText Concept 7.1) * Carbohydrates on the plasma membrane are typically short chains of between two and five monosaccharides. * Carbohydrates are only found associated with the membranes of prokaryotic cells. * The carbohydrate composition of most eukaryotic plasma membranes is quite similar. * Carbohydrates associated with the plasma membrane are located on both surfaces of the membrane. * Membrane carbohydrates function primarily in cell-cell recognition.
Membrane carbohydrates function primarily in cell-cell recognition.
Which of the following is a function of membrane proteins and also facilitates tissue formation during embryogenesis? (eText Concept 7.1) * Membrane proteins attach the membrane to the cytoskeleton. * Membrane proteins with short sugar chains form identification tags that are recognized by other cells. * Membrane proteins form channels, which move substances across the membrane. * Membrane proteins provide receptors for chemical messengers. * All of the listed responses are correct.
Membrane proteins with short sugar chains form identification tags that are recognized by other cells.
Generally, animals cannot digest (hydrolyze) the glycosidic linkages between the glucose molecules in cellulose. How then do cows get enough nutrients from eating grass? (eText Concept 5.2) * Cows and other herbivores are exceptions and make some cellulose-digesting enzymes. * They have to eat a lot of it. * Microorganisms in their digestive tracts hydrolyze the cellulose to individual glucose units. * The flat teeth and strong stomach of herbivores break the cellulose fibers so that the cows get enough nutrition from the cell contents. * All of the listed responses are correct.
Microorganisms in their digestive tracts hydrolyze the cellulose to individual glucose units. Correct. Cows have digestive chambers populated by microorganisms that can produce certain hydrolytic enzymes that cows cannot. The enzymes hydrolyze (digest) the cellulose polymer into glucose monomers.
Responsible for most of a muscle cell's ATP generation
Mitochondria
Which of the following is false? (eText Concept 6.5) * Mitochondria have more than one membrane. * Mitochondria contain ribosomes in the intermembrane space. * Mitochondria are involved in energy metabolism. * The mitochondria possess their own DNA. * The folds of the inner mitochondrial membrane are called cristae.
Mitochondria contain ribosomes in the intermembrane space.
What is a distinguishing feature of most naturally occurring fats? (eText Concept 5.3) * Nearly all naturally occurring unsaturated fats have cis double bonds. * Most unsaturated fats have trans double bonds, causing a kink in the hydrocarbon chain wherever they occur. * All organisms share an equal ratio of saturated and unsaturated fatty acids. * They all share four fused rings as a carbon skeleton. * They are distinguished from other lipid forms by their chief role as components of cell membranes. End of Question 20
Nearly all naturally occurring unsaturated fats have cis double bonds. No. Unsaturated fats with trans double bonds are formed in the industrial process of hydrogenating unsaturated plant oils.
What is a key feature of omega-3 fatty acids that distinguishes them from other types of fatty acids? (eText Concept 5.3) * It is one of the only unsaturated fatty acids that is produced by humans. * Omega-3 fatty acids are distinguished by the presence of three trans double bonds in their hydrocarbon chain. * Omega-3 fatty acids are typically lacking in a vegetarian diet and must be provided by taking animal-derived supplements. * Like other saturated fatty acids, a diet rich in omega-3 fatty acids can promote plaque formation in the blood vessels. * None of the listed responses correctly describes a distinguishing key feature of omega-3 fatty acids
None of the listed responses correctly describes a distinguishing key feature of omega-3 fatty acids.
To what does the term "polypeptide" refer? (eText Concept 5.4) * organic molecules linked by dehydration reactions * carbohydrates with a hydrogen bond holding them together * amino acids linked by hydrolysis * organic monomers covalently bonded * None of the listed responses is correct.
None of the listed responses is correct
Microtubules and microfilaments commonly work with which of the following to perform many of their functions? (eText Concept 6.6) * lysosomes * ribosomes * Golgi apparatus * RNA * None of the listed responses is correct.
None of the listed responses is correct.
Which of the following is a possible reason for grouping the peroxisomes with chloroplasts and mitochondria? (eText Concept 6.5) * They all contain DNA and make some of their own proteins. * They all contain two or more membranes. * They are all part of the plastid family of organelles. * They are all involved in ATP synthesis. * None of these organelles are part of the endomembrane system.
None of these organelles are part of the endomembrane system.
A selectively permeable membrane separates two solutions. Water is able to pass through this membrane; however, sucrose (a disaccharide) and glucose (a monosaccharide) cannot pass. The membrane separates a 0.2-molar sucrose solution from a 0.2-molar glucose solution. With time, how will the solutions change? (eText Concept 7.3) * Water enters the sucrose solution because the sucrose molecule is a disaccharide and thus larger than the monosaccharide glucose. * After the sucrose dissociates into two monosaccharides, water will move via osmosis to the side of the membrane that contains the dissociated sucrose. * The sucrose solution is hypertonic and will gain water because the total mass of sucrose is greater than that of glucose. * Nothing happens because the two solutions are isotonic to one another. * Water leaves the sucrose solution because the sucrose molecule is a disaccharide and thus larger than the monosaccharide glucose.
Nothing happens because the two solutions are isotonic to one another. Correct. Osmotic pressure is produced by the concentration of dissolved substances and is not influenced by the relative sizes of the solutes.
Which of the following statements does NOT agree with the cell theory?
Paramecium comes from Paramecium.
Which of the following statements about passive transport is correct? (eText Concept 7.3) * Passive transport operates independently of the concentrations of the moving solute. * Passive transport operates independently of diffusion. * Passive transport does not occur in the human body. * Passive transport permits the solute to move in either direction, but the net movement of the population of solute occurs down the concentration gradient of the molecule. * In passive transport, solute movement stops when the solute concentration is the same on both sides of the membrane.
Passive transport permits the solute to move in either direction, but the net movement of the population of solute occurs down the concentration gradient of the molecule. Correct. Passive transport can occur in either direction, but the direction of net diffusion is down the concentration gradient of the solute.
Which of the following is a true statement comparing phospholipids and triacylglycerols (fats and oils)? (eText Concept 5.3) * Both molecules contain a phosphate group. * Phospholipids are the primary storage form for fats in our bodies. * Triacylglycerols may be saturated or unsaturated, but all phospholipids are saturated. * Phospholipid molecules have a distinctly polar "head" and a distinctly nonpolar "tail," whereas triacylglycerols are predominantly nonpolar. * In nature, phospholipids occur in fused rings (sterol form), whereas triacylglycerols maintain a straight-chain form.
Phospholipid molecules have a distinctly polar "head" and a distinctly nonpolar "tail," whereas triacylglycerols are predominantly nonpolar. Correct. Triacylglycerols consist of three (nonpolar) fatty acid tails attached to a glycerol molecule. Phospholipids have two fatty acid tails and a hydrophilic head containing a negatively charged phosphate group.
Which of the following statements about the role of phospholipids in the structure and function of biological membranes is correct? (eText Concept 7.1) * Phospholipids form a structure in which the hydrophobic portion faces outward. * They are triacylglycerols, which are commonly available in foods. * Phospholipids are completely insoluble in water. * Phospholipids form a selectively permeable structure. * Phospholipids form a single sheet in water
Phospholipids form a selectively permeable structure.
Which of the following is a FALSE statement about prokaryotes?
Prokaryotes are so small that they can be seen only with an electron microscope.
Which is a difference between prokaryotes and eukaryotes?
Prokaryotes have a nucleoid, whereas eukaryotes have a nucleus.
59) DNA recombination changes the genetic makeup of organisms.
TRUE
Which statement most accurately describes the interactions among ER, ribosomes, and Golgi bodies in exporting protein from the cell?
Ribosomes manufacture proteins, which travel through the ER and are packaged by the Golgi bodies for export.
Site of protein synthesis
Rough endoplasmic reticulum
Nutritionally, saturated triacylglycerols are considered to be less healthful than unsaturated triacylglycerols. What is the difference between them? (eText Concept 5.3) * Saturated triacylglycerols have more double bonds than unsaturated triacylglycerols. * Saturated triacylglycerols have more hydrogen atoms than unsaturated triacylglycerols. * Saturated triacylglycerols are fats; unsaturated triacylglycerols are carbohydrates. * Saturated triacylglycerols are liquid at room temperature. * All of the listed responses are correct.
Saturated triacylglycerols have more hydrogen atoms than unsaturated triacylglycerols. Correct. Saturated triacylglycerols are saturated with hydrogen atoms
60) Sexual reproduction in humans is an example of DNA recombination.
TRUE
Makes steroid hormones
Smooth endoplasmic reticulum
What is the functional connection between the nucleolus, nuclear pores, and the nuclear membrane? (eText Concept 6.3) * The nucleolus contains messenger RNA (mRNA), which crosses the nuclear envelope through the nuclear pores. * Endoplasmic reticulum membrane is produced in the nucleolus and leaves the nucleus through the nuclear pores. * Subunits of ribosomes are assembled in the nucleolus and pass through the nuclear membrane via the nuclear pores. * The nuclear pores are connections between the nuclear membrane and the endoplasmic reticulum that permit ribosomes to assemble on the surface of the ER. * None of the listed responses is correct.
Subunits of ribosomes are assembled in the nucleolus and pass through the nuclear membrane via the nuclear pores. Correct. Proteins and ribosomal RNA are assembled into ribosomal subunits in the nucleolus.
107) In eukaryotic cells, chromosomes are composed of both DNA and proteins.
TRUE
108) Most prokaryotes reproduce via a form of asexual reproduction called prokaryotic fission.
TRUE
109) Bacteria divide through a process called binary fission
TRUE
110) The uncoiled DNA in a eukaryotic cell is much longer than the cell itself.
TRUE
112) Chromosome replication takes place during interphase.
TRUE
113) Cytokinesis takes place during metaphase.
TRUE
114) In prophase, the nuclear membrane disappears.
TRUE
115) Following telophase in animal cells, a cell plate begins to form.
TRUE
116) Normal human cells can go on dividing indefinitely.
TRUE
56) Bacteria lack membrane-bound organelles.
TRUE
58) In nature, DNA recombination occurs but it is random and undirected.
TRUE
65) DNA ligase is important in the replication process because it can join together segments of DNA into a single daughter strand.
TRUE
66) During DNA replication, the continuous daughter strand is the leading strand.
TRUE
66) Ligase enzymes are used to covalently bind together pieces of DNA.
TRUE
66) Organisms that produce disease are pathogens.
TRUE
66) Variation among organisms is due to mutations.
TRUE
67) Adaptations aid in the survival and reproduction of an organism in a particular environment.
TRUE
67) Restriction enzymes have the ability to cut DNA at specific nucleotide sequences.
TRUE
68) The energy that sustains life ultimately comes from sunlight.
TRUE
69) DNA polymerase has the ability to match the nucleotide base in the parental strand with a free nucleotide that is complementary to that base. It then forms the covalent bonds between the nucleotides in the growing daughter strand of DNA.
TRUE
69) Every atom of the same element has an equal number of electrons and protons.
TRUE
69) Photosynthetic bacteria are examples of autotrophs.
TRUE
69) Prions are made up of only protein.
TRUE
70) Acids have pH values below 7, whereas bases have pH values above 7.
TRUE
70) There are potential risks in performing recombinant DNA research on humans and plants.
TRUE
71) Messenger RNA is single-stranded.
TRUE
71) Most mutations are harmful or neutral, although in rare instances some can be beneficial.
TRUE
72) During chemiosmosis, a hydrogen ion gradient is linked to the production of ATP.
TRUE
72) In general, each gene codes for a specific protein.
TRUE
72) When water freezes, stable hydrogen bonds form between the water molecules that create an open, six-sided (hexagonal) arrangement.
TRUE
73) A codon of mRNA consists of three bases that code for an amino acid.
TRUE
73) Water surface tension is a result of the cohesive nature of water molecules.
TRUE
74) Carbon dioxide is considered a waste product of cellular respiration.
TRUE
74) Osmosis is the diffusion of water molecules across selectively permeable membranes.
TRUE
74) The site of protein synthesis in the cytoplasm is the ribosome.
TRUE
74) To maintain a constant pH, buffers act to either accept or release H+.
TRUE
76) Functional groups determine the characteristics and chemical reactivity of organic molecules.
TRUE
77) A duplicated chromosome consists of two sister chromatids.
TRUE
77) Steroid hormones have the ability to regulate transcription.
TRUE
78) Yellow pea color is dominant over green pea color, despite the observation that most store-bought, edible peas are green.
TRUE
79) Mutations may be detrimental, beneficial, or neutral to the cell or organism in which they occur.
TRUE
81) A couple already has 9 children, and they are all girls. If they decide to have a 10th child, it has a 50% chance that it will be male and a 50% chance that it will be female.
TRUE
If all of the lysosomes within a cell suddenly ruptured, what could occur?
The biological molecules in the cell would begin to degrade
If red blood cells are taken from body and placed in a hypertonic solution, what happens to the cells?
The cells shrivel up because water leaves them.
Which of the following provides evidence that mitochondria and chloroplasts were once free-living prokaryotic organisms?
The contain their own DNA.
Which of the following is/are possible site(s) of protein synthesis in a typical eukaryotic cell? (eText Concept 6.5) * the cytoplasm * the rough endoplasmic reticulum * in mitochondria * The first two answers are correct. * The first three answers are correct.
The first three answers are correct. Correct. Ribosomes are present in the cytoplasm, on the rough ER, and in mitochondria (and chloroplasts).
Which of the following describes a difference between DNA and RNA? (eText Concept 5.5) * RNA molecules consist of a single polynucleotide chain, whereas DNA molecules consist of two polynucleotide chains organized into a double helix. * One of their nitrogenous bases is different. * They contain different sugars. * The first and second listed responses are correct differences. * The first three listed responses all describe differences.
The first three listed responses all describe differences.
Which of the following statements correctly describes a common characteristic of a plant cell wall and an animal cell extracellular matrix? (eText Concept 6.7) * Both are permeable to water and small solutes. * Both are synthesized in the ER and Golgi apparatus. * Both are composed primarily of carbohydrates. * The first two answers are correct. * The first three answers are correc
The first two answers are correct. The ECM of animal cells is primarily glycoproteins—proteins with small carbohydrates attached.
The plasma membrane is referred to as a "fluid mosaic" structure. Which of the following statements about that model is true? (eText Concept 7.1) * Only phospholipids are capable of moving in the membrane. * The fluid aspect of the membrane describes its structure at normal temperatures, and the mosaic aspect describes the behavior of the membrane as the temperature is lowered. * The fluid aspect of the membrane is due to the behavior of phospholipids, and the mosaic aspect is due to the presence of carbohydrates. * The mosaic aspect of the membrane is due to the glycosylation of inner leaflet phospholipids. * The fluid aspect of the membrane is due to the lateral and rotational movement of phospholipids, and embedded proteins account for the mosaic aspect.
The fluid aspect of the membrane is due to the lateral and rotational movement of phospholipids, and embedded proteins account for the mosaic aspect.
Which of the following accounts for the fluid aspect of the fluid mosaic model of plasma membranes?
The individual phospholipid molecules are not bonded to one another, so the movement of certain proteins and lipids is possible within the bilayer.
Your intestine is lined with individual cells. No fluids leak between these cells from the gut into your body. Why? (eText Concept 6.7) * The intestinal cells are bound together by gap junctions. * The intestinal cells are bound together by the extracellular matrix. * The intestinal cells are bound together by plasmodesmata. * The intestinal cells are fused together into one giant cell. * The intestinal cells are bound together by tight junctions.
The intestinal cells are bound together by tight junctions. Correct. The membranes of neighboring cells are actually fused at a tight junction, forming a seal that prevents the leakage of extracellular fluid across the layer of epithelial cells.
Amylase is an enzyme that breaks down starch. Why can't the same enzyme break down cellulose? (eText Concept 5.2) * The enzyme cannot attack cellulose because of its helical shape. * The monosaccharide monomers in cellulose are bonded together differently than in starch. * Cellulose molecules are much too large. * The bonds between the monosaccharide monomers in cellulose are much stronger. * Starch is made of glucose; cellulose is made of fructose.
The monosaccharide monomers in cellulose are bonded together differently than in starch. Correct. The glucose monomers in cellulose are bonded in a beta glycosidic linkage, whereas those in starch have an alpha glycosidic linkage. The enzyme amylase is specific for the alpha glycosidic linkage.
Consider the transport of protons and sucrose into a plant cell by the sucrose-proton cotransport protein. Plant cells continuously produce a proton gradient by using the energy of ATP hydrolysis to pump protons out of the cell. Why, in the absence of sucrose, don't protons move back into the cell through the sucrose-proton cotransport protein? (eText Concept 7.4) * The movement of protons through the cotransport protein cannot occur unless sucrose also moves at the same time. * In the absence of sucrose, the ATP-powered proton pump does not function, so there is no proton gradient. * Protons, unlike other substances, do not diffuse down their concentration gradient. * Protons are freely permeable through the phospholipid bilayer, so no transport protein is needed for protons. * Protons cannot move through membrane transport proteins.
The movement of protons through the cotransport protein cannot occur unless sucrose also moves at the same time.
What happens when diffusion moves molecules across the plasma membrane?
The process is relatively slow and is driven by concentration gradients.
Imagine that you fill a shallow tray with water and place a drop of red ink in one end of the tray and a drop of green ink in the other end. Which of the following is TRUE at equilibrium?
The red and green inks are both uniformly distributed throughout the tray.
Active transport requires an input of energy and can also generate voltages across membranes. Based on this information, which of the following statements is true? (eText Concept 7.4) * Active transport can use ATP as its energy source and ensures that there is no voltage across the cell membrane. * The sodium/potassium pump hydrolyzes ATP and results in a net charge of +1 outside the cell membrane. * Active transport moves solutes down their concentration gradients and always uses ATP as the source of energy to do this. * Active transport uses channel proteins and ensures that the interior of the cell is always positive compared to the exterior of the cell. * The source of energy for active transport of a solute up its gradient can be ATP or a concentration gradient of a second solute. This second gradient of solutes maintains no net difference in voltage across the membrane
The sodium/potassium pump hydrolyzes ATP and results in a net charge of +1 outside the cell membrane.
Phospholipids spontaneously form a bilayer in an aqueous solution. Why do the heads of the phospholipids point out and the tails point toward one another?
The tails are repelled by the aqueous environment.
According to the fluid mosaic model of cell membranes, which of the following is a TRUE statement about membrane phospholipids?
They form a viscous fluid through which proteins shift and flow.
Within the fluid mosaic of a plasma membrane, what is the role of transport and channel proteins?
They permit salts and sugars to move through the plasma membrane.
Imagine an artificial cell made with a selectively permeable membrane that allows water to pass through but does not allow sugar to pass. If you fill this cell with a 1% sugar solution and then you place the cell in a 2% sugar solution, what happens?
Water leaves the cell.
Two aqueous solutions are separated by a selectively permeable membrane that allows water to pass through but does not allow starch to pas through. Solution A is 10% starch and solution B is 5% starch. What will occur?
Water will diffuse from solution B to solution A.
A single plant cell is placed in an isotonic solution. Salt is then added to the solution. Which of the following would occur as a result of the salt addition? (eText Concept 7.3) * There would be no osmotic movement of water in response to the added salt. * The added salt would enter the cell, causing the cell to take up water and swell. * The added salt makes the solution hypotonic compared to the cell. Water will enter the cell by osmosis. * Water would leave the cell by osmosis, causing the volume of the cytoplasm to decrease. * Water would enter the cell by osmosis, and the cell would swell.
Water would leave the cell by osmosis, causing the volume of the cytoplasm to decrease. Correct. The added salt makes the solution hypertonic compared to the cell. Water will leave the cell by osmosis.
The bacterium Vibrio cholerae releases a toxin that blocks a channel protein in the membranes of cells that line the intestine. This toxin prevents the movement of positively changed sodium ions out of the intestine and into the cells. If the sodium ions could not move into the cells, how would the affect the movement of water?
Water would leave the cells and enter the intestines by osmosis.
If a small droplet of triacylglycerol molecules is suspended in water, the fat molecules form a "ball of spaghetti" with no particular orientation. But if a droplet of phospholipid molecules is put in water, all the molecules point outward, toward the water. Phospholipids are forced into this orientation because phospholipids have _____. (eText Concept 5.3) * two charged ends * three fatty acid molecules, all pointing in different directions * a charged end and a noncharged end * both a saturated fatty acid and an unsaturated fatty acid * two fatty acid molecules pointing in different directions
a charged end and a noncharged end Correct. The hydrocarbon tails of phospholipids are hydrophobic and are excluded from water. The negatively charged phosphate group and its attachments form a hydrophilic head that is attracted to water.
The peptide bond is _____. (eText Concept 5.4) * a covalent bond joining amino acids together to form a polypeptide * a hydrogen bond joining amino acids together to form a polypeptide * a covalent bond joining simple sugars together to form a polypeptide * a covalent bond joining nucleotides together to form a nucleic acid * a hydrogen bond joining nucleotides together to form a nucleic acid
a covalent bond joining amino acids together to form a polypeptide
The nuclei of eukaryotic cells are characterized by:
a double membrane
For diffusion to occur, there must be:
a gradient
The concentration of solutes in a red blood cell is about 2%, but red blood cells contain almost no sucrose or urea. Sucrose cannot pass through the membrane, but water and urea can. Osmosis would cause red blood cells to shrink the most when immersed in which of the following solutions? (eText Concept 7.3) * a hypotonic urea solution * pure water * a hypotonic sucrose solution * a hypertonic urea solution * a hypertonic sucrose solution
a hypertonic sucrose solution Correct. When a cell is placed in a hypertonic environment, water will leave the cell, causing it to shrink.
Which of the following would be least likely to diffuse through a plasma membrane without the help of a transport protein? (eText Concept 7.2) * a large polar molecule * dissolved gases such as oxygen or carbon dioxide * a small nonpolar molecule * a large nonpolar molecule * Any of the above would easily diffuse through the membran
a large polar molecule
Which of the following is the thinnest?
a microfilament
All cell posses all of the following components EXCEPT:
a nuclear membrane
What is NOT a feature of a prokaryotic cell?
a nuclear membrane
A glucose molecule is to starch as _____. (eText Concept 5.5) * a nucleic acid is to a polypeptide * a protein is to an amino acid * a nucleotide is to a nucleic acid * a steroid is to a lipid * an amino acid is to a nucleic acid
a nucleotide is to a nucleic acid
In addition to the fundamental structures required to be defined as a cell, a particular cell also has a nucleus and chloroplasts. Based on this information, this cell could be _____. (eText Concept 6.2) * a yeast (fungus) cell * a cell from the intestinal lining of a cow * a protistal cell and a plant cell * a bacterium * a cell from a pine tree
a protistal cell and a plant cell Correct. Some protists (e.g. algae) can photosynthesize and so do plants. As the protista and plants are both eukaryotes, they contain organelles.
The cytoplasm of a certain cell, such as a neuron, already has a high concentration of K+ ions. How K+ ions continue to enter the cell?
active transport
Which of the following requires adenosine triphosphate?
active transport
Manufacturers make vegetable oils solid or semisolid at room temperature by _____. (eText Concept 5.3) * adding hydrogen atoms to the single bonds of the fatty acid hydrocarbon chains * adding hydrogen atoms to the double bonds in the fatty acid hydrocarbon chains * removing hydrogen atoms and forming additional double bonds in the fatty acid hydrocarbon chains * removing hydrogen atoms and forming additional single bonds in the fatty acid hydrocarbon chains * None of the listed responses is correct.
adding hydrogen atoms to the double bonds in the fatty acid hydrocarbon chains No. If hydrogen atoms were removed, additional double bonds would be formed.
On the basis of the principle of complementary base pairing, you would expect the percentage of _____ to be equal to the percentage of _____. (eText Concept 5.5) * adenine ... thymine * thymine ... guanine * thymine ... cytosine * adenine ... guanine
adenine ... thymine
The formation of ATP in the mitochondria, which is an oxygen-dependent reaction, is called:
aerobic metabolism.
Protein molecules are polymers (chains) of _____. (eText Concept 5.4) * sucrose molecules * DNA molecules * amino acid molecules * purines and pyrimidines * fatty acid molecules
amino acid molecules Correct. Polymers of amino acids are called polypeptides. A protein consists of one or more polypeptides folded into specific conformations.
A nucleolus is:
an area in the nucleus where ribosomes are made
Which type of microscope has the best resolution?
an electron microscope
A particular cell has the following molecules and structure: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. It could be a(n) ____________ cell.
animal, but not plant
Lipids differ from other large biological molecules in that they _____. (eText Concept 5.3) * do not contain nitrogen and phosphorus atoms * do not have specific shapes * are much larger * are not truly polymers * do not contain carbo
are not truly polymers
Which of the following types of membrane proteins are responsible for connecting cells to one another?
attachment proteins
Prokaryotes that are rod-shaped are called:
bacilli
If you removed the sex pili from a bacterial cell, then the:
bacterium could no longer exchange DNA with other cells.
Which of the following is the simplest collection of matter that can live? eText Overview * molecules * tissue * cell * organ * None of the listed responses is correct.
cell
Consider two cells with the same volume but with very different surface areas due to differences in their shapes. The cell with the larger surface area is likely to _____. (eText Concept 6.2) * be involved in the rapid uptake of compounds from the cell's environment * be a prokaryotic cell * be nearly spherical in shape * have a very high metabolic rate * be buried deep in the interior of an organism
be involved in the rapid uptake of compounds from the cell's environment
In biological membranes, the phospholipids are arranged in a:
bilayer with the fatty acids pointing toward one another.
Mitochondria and chloroplasts share all of the following characteristics EXCEPT that they:
capture the energy of sunlight to meet metabolic demands.
Which of the following molecules is most likely to passively diffuse across the plasma membrane? (eText Concept 7.2) * carbon dioxide * glucose * hemoglobin * DNA * sodium ion
carbon dioxide
Which of the following would not be found in a membrane?
cellulose
Which of the following components of a tossed salad will pass through the human digestive tract and be digested the least? (eText Concept 5.2) * cellulose (in the lettuce) * starch (in the croutons) * protein (in the bacon bits) * sugar (in the dressing) * oil (in the dressing)
cellulose (in the lettuce) Correct. Cellulose contains glycosidic linkages that cannot be broken by human digestive enzymes.
Which of the following is a polymer? (eText Concept 5.2) cellulose, a plant cell wall component fructose, a component of sucrose glucose, an energy-rich molecule triacylglycerol, or fat testosterone, a steroid hormone
cellulose, a plant cell wall component Correct. The polysaccharide cellulose is a major component of plant cell walls. It is a polymer composed of many glucose monomers joined together by glycosidic linkages.
Which of the following structures is found in animal cells but NOT plant cells? (eText Concept 6.6) * mitochondria * plasma membrane * Golgi apparatus * centrioles * rough endoplasmic reticulum
centrioles
Which type of protein shields a newly forming protein from cytoplasmic influences while it is folding into its functional form? (eText Concept 5.4) * fibrous proteins * enzymes * receptor proteins * antibodies * chaperonins
chaperonins Correct. Chaperonins shield proteins from "bad influences" (interactions with other molecules in the cytoplasm) while they are folding into their functional forms.
At a conference, the speaker's grand finale was sautéing mealworms (insect larvae) in butter and serving them to the audience. They were crunchy (like popcorn hulls) because their exoskeletons contain the polysaccharide _____. (eText Concept 5.2) * chitin * glycogen * cellulose * collagen * linoleic acid
chitin Correct. Chitin is the structural polysaccharide found in arthropod exoskeletons.
Which of the following is capable of converting light energy into chemical energy?
chloroplasts
Which pair of organelles is responsible for supplying energy to eukaryotic cells?
chloroplasts and mitochondria
Which of the following relationships is FALSE?
chloroplasts- chief site of lipid synthesis
The cytoplasm of eukaryotic cells contains all of the following EXCEPT:
chromosomes
No prokaryotic cells have:
cilia
Basal bodies are most closely associated with which of the following cell components? (eText Concept 6.6) * the central vacuole * mitochondria * nucleus * Golgi apparatus * cilia
cilia No. Basal bodies are made up of components of the cytoskeleton and are not associated with the nucleus.
Carbon dioxide crosses the plasma membrane by simple diffusion. The rate at which carbon dioxide enters the cell is determined by the:
concentration of carbon dioxide on each side of the membrane.
A cell from a wheat plant contains all the following EXCEPT a:
contractile vacuole
The type of bond that forms to join monomers (such as sugars and amino acids) into polymers (such as starch and proteins) is a(n) _____ bond. (eText Concept 5.1) * hydrogen * ionic * van der Waals * peptide * covalent
covalent
Which of the following correctly describes a general property of all electrogenic pumps? (eText Concept 7.4) * create a voltage difference across the membrane * pump sodium out of the cell and potassium into the cell * can pump a large variety of solutes across a membrane against their concentration gradient * a cell with a high internal concentration of protons * a cell with an interior that is positively charged relative to the outside of the cell
create a voltage difference across the membrane Correct. An electrogenic pump creates a net charge difference across a membrane (a membrane potential).
Of the following cell components, which is composed primarily of protein:
cytoskeleton
What primarily determines the shape of animal cells, which lack cell walls?
cytoskeleton
Where would you expect to find proteins involved with movement of structures within a cell? (eText Concept 6.6) * muscles * ribosomes * cytoskeleton * plasma membrane * transport vesicles moving from the ER to the Golgi
cytoskeleton Correct. Movement of organelles and vesicles within cells is accomplished by the cytoskeleton.
What is the process by which monomers are linked together to form polymers? (eText Concept 5.1) * coiling * protein formation * hydrolysis * monomerization * dehydration or condensation reactions
dehydration or condensation reactions
Recognition proteins are most important for:
distinguishing foreign cells from cells from "self" cells.
Plasma membranes are BEST described as a:
double layer of phospholipids with hydrophobic tails oriented toward one another.
Consider a protein that is made in the rough endoplasmic reticulum. You observe that when the synthesis of the protein is completed, the protein is located in the ER membrane. Where else in the cell might this protein be found? (eText Concept 6.4) * in the aqueous interior of a lysosome functioning as a digestive enzyme * in the cytoplasm functioning as an enzyme in carbohydrate synthesis * in the internal space of the Golgi apparatus, being modified before the protein is excreted * embedded in the plasma membrane functioning in the transport of molecules into the cell * in a mitochondrion functioning in ATP synthesis
embedded in the plasma membrane functioning in the transport of molecules into the cell
A nursing infant is able to obtain disease-fighting antibodies, which are large protein molecules, from its mother's milk. These molecules probably enter the cells lining the baby's digestive tract via which process? (eText Concept 7.5) * passive transport * active transport * endocytosis * exocytosis * osmosis
endocytosis Correct. Endocytosis is the procedure that cells use to import large molecules across their plasma membrane.
Which of the following cell structures is not found in a bacterial cell?
endoplasmic reticulum
Carbohydrates are used in our bodies mainly for _____. (eText Concept 5.2) * building genetic material * lipid storage * structural molecules, such as hair and fingernails * energy storage and release * membrane construction
energy storage and release Correct. Simple sugar molecules, stored in polysaccharides such as glycogen in animals and starch in plants, are a major energy source for cellular work
Which of the following functional processes is not a consequence of the association of proteins with biological membranes? (eText Concept 7.1) * cell-cell communication * intercellular joining * enzymatic activity * cell-cell recognition * energy, carbon, and nitrogen storage
energy, carbon, and nitrogen storage
Some lipids are formed when fatty acids are linked to glycerol. These subunits are linked together by _____. (eText Concept 5.3) * ester linkages * glycosidic linkages * peptide bonds * ionic bonds * phosphodiester linkages
ester linkages
The secretion of excess water via the contractive vacuole of a Paramecium cell is an example of:
exocytosis
Which of the following occurs as an enzyme produced by a secreted from the cell?
exocytosis
Which of the following processes and organelle(s) accounts for the replacement of lipids and proteins lost from the plasma membrane? (eText Concept 7.5) * flip-flop of phospholipids from one side of the plasma membrane to the other and the Golgi * active transport and the rough endoplasmic reticulum * endocytosis and Golgi * receptor-mediated endocytosis and smooth ER and Golgi * exocytosis and smooth and rough ER
exocytosis and smooth and rough ER No. Although the Golgi is involved in the shipment of phospholipids to the plasma membrane, endocytosis is a process that removes phospholipids from the plasma membrane by budding off of small vesicles.
The hydrophilic regions of a membrane protein are most likely to be found:
exposed on the surface of the membrane
Which of the following is NOT a function of plastids?
extracting energy from food and converting it to ATP
Glucose is a six-carbon sugar that diffuses slowly through artificial phospholipids bilayers. the cells lining the small intestine, however, rapidly move large quantities of glucose from the glucose-rich food into their glucose- poor cytoplasm. Given this information, which transport mechanism is most probably functioning in the intestinal cells?
facilitated diffusion
Molecules assisted by carrier proteins may cross a selectively permeable membrane by:
facilitated diffusion
A cell has a membrane potential of -100 mV (more negative inside than outside) and has 1,000 times more calcium ions outside the cell than inside. Which of the following best describes a mechanism by which Ca2+ enters the cell? (eText Concept 7.4) * passive diffusion of Ca2+ into the cell down its electrochemical gradient * movement of Ca2+ into the cell through an ion channel down its concentration gradient * movement of Ca2+ into the cell through a carrier protein down its electrical gradient * facilitated diffusion of Ca2+ into the cell down its electrochemical gradient * cotransport of Ca2+ into the cell with Cl-
facilitated diffusion of Ca2+ into the cell down its electrochemical gradient
Phospholipids are:
found in cell membranes
Which of the following organelles is unlikely to show enhanced abundance in pancreatic cells that secrete large amounts of digestive enzymes? (eText Concept 6.4) * free cytoplasmic ribosomes * Golgi apparatus * transport vesicles * rough endoplasmic reticulum * All of the listed responses will increase in pancreatic cells secreting digestive enzymes.
free cytoplasmic ribosomes
Which of the following is/are most likely to be involved in the process of producing proteins for a chloroplast or mitochondrion? (eText Concept 6.4) ** the Golgi apparatus * smooth endoplasmic reticulum * transport vesicles * rough endoplasmic reticulum * free cytoplasmic ribosomes
free cytoplasmic ribosomes No. The smooth ER is part of the endomembrane system; chloroplasts and mitochondria are not.
Of the objects listed, which is the smallest that you can see with the unaided eye?
frog embryo
A freshwater protozoan, such as Paramecium, tends to ___________ because it lives in a ____________ environment.
gain water; hypotonic
Which of the following carbohydrate molecules has the lowest molecular weight? (eText Concept 5.2) * glucose * cellulose * sucrose * chitin * lactose
glucose
A polysaccharide that is used for storing energy in human muscle and liver cells is _____. (eText Concept 5.2) * chitin * glucose * starch * glycogen * cellulose
glycogen
The major histocompatibility complex (MHC) is an example of a(n):
glycoprotein
Some of the most important molecules that are embedded within that bilayer membrane of cell, such as the molecules that allow for transport and cell recognition, are:
glycoproteins
the subunits (monomers) in cellulose are linked together by _____. (eText Concept 5.2) * glycosidic linkages * peptide bonds * ionic bonds * phosphodiester linkages * ester linkages
glycosidic linkages
Bacterial cells are prokaryotic. Unlike a typical eukaryotic cell they _____. (eText Concept 6.2) * have no membrane-bounded organelles in their cytoplasm * lack a plasma membrane * lack chromosomes * have no ribosomes * have a smaller nucleus
have no membrane-bounded organelles in their cytoplasm
ISO membranes are inside-out membrane vesicles used by researchers in membrane in membrane studies. As a molecule diffuses into the vesicle, it will encounter the layers of the membrane in the following order:
head-tail-tail-head
The phospholipids that make up the plasma membrane have ___________ heads and ____________ tails.
hydrophilic; hydrophobic
Which is the term for compounds that do not mix with water? (eText Concept 5.3) * proteins * hydrophilic * hydrogen-bonded * phospholipids * hydrophobic
hydrophobic Correct. Hydrophobic compounds are those that are insoluble in water.
The fatty acid tails of a phospholipid are _____ because they _____. (eText Concept 5.3) * hydrophobic ... have no charges to which water molecules can adhere * hydrophobic ... dissolve easily in water * hydrophobic ... consist of units assembled by dehydration reactions * hydrophilic ... consist of units assembled by dehydration reactions * hydrophilic ... are easily hydrolyzed into their monomers
hydrophobic ... have no charges to which water molecules can adhere
Suppose that plasma membranes were single layers of phospholipids with heads facing the external environment. The interior of this hypothetical cell would have to be:
hydrophobic and nonpolar
Solutions that cause water to enter cells by osmosis are called:
hypotonic
Chloroplasts and mitochondria are thought to be of prokaryotic origin. One piece of evidence that supports this hypothesis is that these organelles contain prokaryotic-like ribosomes. These ribosomes are probably most similar to ribosomes found _____. (eText Concept 6.5) * free in the cytoplasm of eukaryotes * on the rough ER * in bacterial cells * The first two answers are correct. * The first three answers are correct.
in bacterial cells Correct. Like the ribosomes in bacteria, the ribosomes in the mitochondria are smaller than those found free in the cytoplasm or bound to endoplasmic reticulum in the eukaryotes
Consider the currently accepted fluid mosaic model of the plasma membrane. Where in the plasma membrane would cholesterol most likely be found? (eText Concept 7.1) * in the interior and on the inside surface, but not on the outside surface * on the inside (cytoplasmic) surface * in the interior of the membrane * on the outside (external) surface of the membrane * on either surface of the membrane, but not in the interior of the membrane
in the interior of the membrane No. Cholesterol is hydrophobic and will be found in the interior of the bilayer membrane.
A protein that ultimately functions in the plasma membrane of a cell is most likely to have been synthesized _____. (eText Concept 6.4) * in the ribosomes of the mitochondria * on free cytoplasmic ribosomes * in the rough endoplasmic reticulum * in the smooth endoplasmic reticulum * in the plasma membrane
in the rough endoplasmic reticulum Correct. All of the membrane proteins of the endomembrane systems are made in the rough ER.
The walls of plant cells are largely composed of polysaccharides and proteins that are synthesized _____. (eText Concept 6.7) * in the rough endoplasmic reticulum * externally to the plasma membrane * in the Golgi apparatus * in the smooth endoplasmic reticulum * in the rough endoplasmic reticulum and in the Golgi apparatus
in the rough endoplasmic reticulum and in the Golgi apparatus
The hydrophobic tails of a phospholipid bilayer are oriented toward the:
interior of the plasma membrane (i.e., toward one another).
Suppose you have two glucose solutions separated by a selectively permeable membrane. If there is a concentration gradient of glucose across the membrane, then one of the solutions cannot be:
isotonic
If a cell contains large amounts of rough ER, then:
large amounts of protein hormones could be exported by the cell.
Which of the following is visible ONLY with an electron microscope?
large protein
What is active transport?
movement of molecules into or out of a cell against a concentration gradient
A researcher wants to film the movement of chromosomes during cell division. Which type of microscope should she choose and why is it the best choice? (eText Concept 6.1) * transmission electron microscope, because of its high magnifying power * light microscope, because of its high resolving power * scanning electron microscope, because of its ability to visualize the surface of subcellular objects * transmission electron microscope, because of its high resolving power * light microscope, because the specimen is alive
light microscope, because the specimen is alive
The __________ portion of the cell membrane is responsible for the isolating functions of the membrane, while the __________ portion regulates exchange and communication with the environment.
lipid; protein
The sex hormones estrogen, progesterone, and testosterone belong to which class of molecules? (eText Concept 5.3) * proteins * lipids * amino acids * nucleic acids * carbohydrates
lipids Correct. Steroids, such as estrogen, progesterone, and testosterone, are lipids based on their insolubility in water. The molecules are characterized by a carbon skeleton consisting of four fused rings of carbon atoms.
The compounds in biological membranes that form a barrier to the movement of materials across the membranes are:
lipids.
Osmosis moves water from a region of:
low concentration of dissolved material to a region of high concentration.
Which of the following categories best describes the function of the rough endoplasmic reticulum? (eText Concept 6.4) * energy processing * information storage * breakdown of complex foods * manufacturing * structural support of cells
manufacturing
When a mouse cell and a human cell are fused, the membrane proteins of the two cells become uniformly distributed over the surface of the hybrid cell. This occurs because:
many proteins can move around within the bilayer.
Which of the following structures is found in eukaryotic but not prokaryotic cells? (eText Concept 6.2) * ribosomes * plasma membrane * DNA * mitochondria * cytosol
mitochondria
Which organelle is most abundant in cardiac muscle cells?
mitochondria
Which of the following five membranes is most likely to have a lipid composition that is distinct from the other four? (eText Concept 6.5) * Golgi apparatus * mitochondrial outer membrane * endoplasmic reticulum * plasma membrane * lysosome membrane
mitochondrial outer membrane
Aerobic metabolism occurs in the:
mitochondrion
Cilia and flagella move due to the interaction of the cytoskeleton with which of the following? (eText Concept 6.6) * tubulin * actin * motor proteins * mitochondria * pseudopodia
motor proteins
Flagellated cells can:
move through the cell fluid.
Which type of cell is most likely to have the most mitochondria? (eText Concept 6.5) * photosynthetic cells in the leaves of a tree * inactive yeast cells that are stored for future use * bacterial cells that are growing on sugars * muscle cells in the legs of a marathon runner * nondividing cells in the skin on your finger
muscle cells in the legs of a marathon runner Correct. Cellular respiration releases energy that cells need to carry out their functions. Active muscle cells need a lot of energy.
The observation that chloroplasts and mitochondria each contain their own DNA and synthesize some of the proteins that function in these organelles suggests that chloroplasts and mitochondria _____. (eText Concept 6.5) * are produced by the nucleus of the cell * contain two or more membranes * are part of the endomembrane system * must divide each time the cell containing them divides * are involved in energy metabolism of the cell
must divide each time the cell containing them divides
A cell with a large number of lysosomes would most likely be very active in:
phagocytosis.
A nucleotide is made of which of the following chemical components? (eText Concept 5.5) * a series of nitrogenous bases, a nucleic acid backbone, and a hexose sugar * a nitrogenous base, an amino acid, and a pentose sugar * a nitrogenous base, an amino acid, and a phosphate group * a nitrogenous base, a fatty acid, and an amino acid * a nitrogenous base, a phosphate group, and a pentose sugar
nitrogenous base, a phosphate group, and a pentose sugar Correct. Each nucleotide consists of three parts: an organic molecule, called a nitrogenous base; a 5-carbon sugar, called a pentose; and a phosphate group that serves in the phosphodiester covalent bond that forms a bridge between adjacent nucleotides.
In reference to diffusion, "passive" really means:
no energy required.
Which of the following is the major energy storage compound of plant seeds? (eText Concept 5.3) * cellulose * glycogen * lipids * amylose * oils
oils
Consider the currently accepted fluid mosaic model of the plasma membrane. Where in the membrane would carbohydrates most likely be found? (eText Concept 7.1) * Carbohydrates are rarely associated with plasma membranes. * on the inside (cytoplasmic) surface of the membrane * on both hydrophilic surfaces of the membrane but not in the hydrophobic interior * on the outside (external) surface of the membrane * in the interior of the membrane
on the outside (external) surface of the membrane
Membrane protein are synthesized on ribosomes that are found:
on the rough endoplasmic reticulum.
To say that a cell is "selectively permeable" means:
only certain molecules can pass through
The diffusion of water molecules across a selectively permeable membrane is called:
osmosis
When substances move through a plasma membrane and down gradients of concentration, this is called:
passive transport
The process in which white blood cells engulf bacteria is termed:
phagocytosis
The lipids that form the main structural component of cell membranes are _____. (eText Concept 5.3) * carbohydrates * triacylglycerols * cholesterol * proteins * phospholipids
phospholipids Correct. Phospholipids have a hydrophilic head and two hydrophobic tails. This permits the phospholipids to be arranged in a bilayer, or double layer, which forms a boundary between the cell and its external environment.
The main lipids found in cell membranes are:
phospholipids.
Which of the following pairs correctly matches a membrane transport process to its primary function? (eText Concept 7.5) * phagocytosis ... secretion of large particles from the cell by fusion of vesicles with the plasma membrane * osmosis ... passive diffusion of water and small solutes across a membrane * pinocytosis ... the uptake of water and small solutes into the cell by formation of vesicles at the plasma membrane * exocytosis ... the movement of water and solutes out of the cell by vesicle fusion with the plasma membrane * None of the above is correct.
pinocytosis ... the uptake of water and small solutes into the cell by formation of vesicles at the plasma membrane No. In phagocytosis (cellular eating), a type of endocytosis, a cell engulfs a particle by wrapping pseudopodia around it and packaging it within a membrane-enclosed sac large enough to be classified as a food vacuole
Plastids are found in __________ cells.
plant
The small, circular loops of DNA in prokaryotic cells that are separate from the main chromosome and may harbor genes are called:
plasmids.
Dye injected into a plant cell might be able to enter an adjacent cell through _____. (eText Concept 6.7) * a microtubule * plasmodesmata * a tight junction * a gap junction * a cell wall
plasmodesmata No. Although microtubules are hollow, they are a component of the cytoskeleton and do not connect the cytoplasm of adjacent cells
Cellulose is a _____ made of many _____. (eText Concept 5.2) *polymer ... glucose molecules * carbohydrate ... fatty acids * lipid ... triacylglycerols * protein ... amino acids * polypeptide ... monomers
polymer ... glucose molecules Correct. Cellulose is a polysaccharide and therefore a polymer, constructed from many monosaccharide glucose monomers.
in a hydrolysis reaction, _____, and in this process water is _____. (eText Concept 5.1) * a monomer is broken up into its constituent polymers ... produced * monomers are assembled to produce a polymer ... produced * monomers are assembled to produce a polymer ... consumed * a polymer is broken up into its constituent monomers ... produced * a polymer is broken up into its constituent monomers ... consumed
polymer is broken up into its constituent monomers ... consumed In hydrolysis water is utilized as a reactant; water is not a product of a hydrolysis reaction.
Fibers of the cytoskeleton are composed of primarily:
protein
Which of the following lists ranks these molecules in the correct order by size? (eText Concept 5.4) * water, sucrose, glucose, protein * protein, sucrose, glucose, water * protein, water, glucose, sucrose * water, protein, sucrose, glucose * glucose, water, sucrose, protei
protein, sucrose, glucose, water Correct. In this case, the ranking is from largest to smallest.
In general, which of the following is largely responsible for moving substances across the plasma membrane, communicating with other cells, and identifying the cell?
proteins
Ribosomes are the site of synthesis of:
proteins
Which of the following types of information is/are most likely to be derived from freeze-fracture of biological samples? (eText Concept 7.1) * number of ribosomes associated with the rough endoplasmic reticulum * the information coded for by DNA * patterns of movement in living cells * proteins embedded in membrane bilayers * the structure of pili
proteins embedded in membrane bilayers No. A freeze-fracture does not sequence DNA nucleotides.
Which of the following structural arrangements of the components in biological membranes is most consistent with membrane's property of selective permeability? (eText Concept 7.2) * proteins embedded in two layers of phospholipid * a layer of protein coating a layer of phospholipid * a phospholipid bilayer with proteins scattered on the surfaces of the membranes * phospholipids sandwiched between two layers of protein * proteins sandwiched between two layers of phospholipid
proteins embedded in two layers of phospholipid
Cell membranes do all of the following EXCEPT:
provide shape and structure to a cell.
Which of the following types of membrane proteins are responsible for conveying external messages such as those sent by a hormone signal?
receptor proteins
Which of the following is an energy-requiring mode of transport that brings substances into a cell?
receptor-mediated endocytosis
Which of the following enables a cell to pick up and concentrate a specific kind of molecule? (eText Concept 7.5) * receptor-mediated endocytosis * channel proteins * passive transport * facilitated diffusion * osmosis
receptor-mediated endocytosis Correct. In receptor-mediated endocytosis, only a specific molecule, called a ligand, can bind to the receptor. Without receptor binding occurring first, endocytosis does not proceed.
What prevents your immune system from attacking your own cells?
recognition proteins
Cells use exocytosis to:
release substances from the cell.
Molecules that permeate a plasma membrane by facilitated diffusion:
require the aid of transport proteins.
Which of the following does NOT posses a double membrane?
ribosome
Which of the following groups is primarily involved in synthesizing molecules needed by the cell? (eText Concept 6.4) * rough endoplasmic reticulum, lysosome, vacuole * vacuole, rough endoplasmic reticulum, smooth endoplasmic reticulum * smooth endoplasmic reticulum, ribosome, vacuole * ribosome, rough endoplasmic reticulum, smooth endoplasmic reticulum * lysosome, vacuole, ribosome
ribosome, rough endoplasmic reticulum, smooth endoplasmic reticulum Correct. Each of these structures is capable of synthesizing molecules needed by cells
Both prokaryotic and eukaryotic cells posses:
ribosomes
Which of the following is associated with rough ER?
ribosomes
Which of the following lack membranes as part of their structure? (eText Concept 6.5) * peroxisomes * mitochondria * ribosomes * ribosomes and mitochondria * mitochondria and peroxisomes
ribosomes
Which of the following organelles might be found inside other organelles? (eText Concept 6.5) * ribosomes * the nucleolus * transport vesicles * mitochondria * No organelles are found inside of other organelles.
ribosomes
Which of the following features do prokaryotes and eukaryotes have in common? (eText Concept 6.2) * mitochondria, ribosomes, cytoplasm * mitochondria, cytoplasm, plasma membrane * ribosomes, plasma membrane, cytoplasm * ribosomes, nucleus, plasma membrane * nucleus, plasma membrane, ribosomes
ribosomes, plasma membrane, cytoplasm Prokaryotes lack organelles.
the alpha helix and beta pleated sheet represent which level of protein structure? (eText Concept 5.4) * secondary structure * pentiary structure * tertiary structure * primary structure * quaternary structure
secondary structure
You would expect a cell with an extensive Golgi apparatus to _____. (eText Concept 6.4) * move rapidly * absorb nutrients in the GI tract * store large quantities of ions * make a lot of ATP * secrete a lot of protein
secrete a lot of protein
Cell fractionation _____. (eText Concept 6.1) * is no longer used in modern cell biology * separates cells into their component parts * requires the use of a scanning electron microscope * uses strong acids to break apart cells * None of the listed responses is correct.
separates cells into their component parts Correct. The organelles are usually separated by centrifugation.
The gases O2 and CO2 enter or leave a pant cell by:
simple diffusion
The net movement of molecules from a high concentration to a low concentration is BEST described by which of the following?
simple diffusion
All of the following may influence the rate of simple diffusion across a selectively permeable membrane EXCEPT the:
size of the cell.
Cells that primarily produce steroid hormones, such as testosterone and estrogen, have large quantities of:
smooth endoplasmic reticulum
All of the following are dependent on cilia EXCEPT the:
sperm of animals
In what polysaccharide form do plants store glucose to be available later as an energy source? (eText Concept 5.2) * protein * starch * glycogen * cellulose * fatty acids
starch
The polysaccharide that you are most likely to have eaten recently is _____. (eText Concept 5.2) * glucose * starch * ribose * chitin * lactose
starch Correct. Starch is a storage polysaccharide found especially in certain plant tissues.
A mutant plant cell with no chloroplast would:
still be able to use carbohydrates as an energy source
All of the following are important functions od the cytoskeleton EXCEPT:
storage of food molecules.
What is the function of a plant cell vacuole?
stores water
Carbohydrates can function in which of the following ways? (eText Concept 5.2) * structural support * energy storage * information storage * enzymatic catalysis * structural support and energy storage
structural support and energy storage
If a frog cell is placed into a hypotonic solution, it will:
swell via osmosis
The overall three-dimensional shape of a single polypeptide is called the _____. (eText Concept 5.4) * secondary structure * primary structure * tertiary structure * double helix * quaternary structure
tertiary structure
A dish of animal cells was grown in the presence of radioactive phosphorous. The phosphorous largely ended up in nucleotides inside the actively growing animal cells. In which cellular structure(s) would you predict the majority of the radioactive phosphorous to accumulate? (eText Concept 6.4) * the nucleus * the Golgi apparatus and the nucleus * the Golgi apparatus * rough endoplasmic reticulum and Golgi apparatus
the nucleus Correct. Large numbers of nucleotides would be used to make new DNA as the cells grew, and the DNA is housed in the nucleus.
In a 1-4 glycosidic linkage, _____. (eText Concept 5.2) * one monosaccharide is bound to four others * the number 1 carbon in one monosaccharide is bound to the number 4 carbon in another monosaccharide * there are four possible isomers of the structure * the number 1 carbon in one nucleotide is bound to the number 4 carbon in another nucleotide * one glycerol molecule is bound to four fatty acids
the number 1 carbon in one monosaccharide is bound to the number 4 carbon in another monosaccharide
A substance moving from outside the cell into the cytoplasm must pass through _____. (eText Concept 6.2) * the nucleus * the plasma membrane * a ribosome * a microtubule * the endomembrane system
the plasma membrane
Which of the following cell structures exhibits selective permeability between a cell and its external environment? (eText Overview) * lysosomes * chloroplasts * endoplasmic reticulum * mitochondria * plasma membrane
the plasma membrane
Glucose can be moved into cells via two mechanisms. An active transport mechanism can be used when the concentration of glucose inside the cell is higher than the concentration of glucose outside of the cell. This active transport mechanism moves glucose and sodium into the cell at the same time. The glucose moves up its gradient and the sodium moves down its gradient. Which of the following statements about this mechanism is most true? (eText Concept 7.4) * The protein that moves the sodium and glucose into the cell is an antiporter. * To pump glucose up its concentration gradient, sodium is moving down its concentration gradient. * The sodium forms an electrochemical gradient in this mechanism. * The first two responses are correct. * The second and third responses are correct.
the second and third responses are correct. Correct. The movement of sodium down its gradient drives glucose up its gradient, and because sodium is at different concentrations on either side of the membrane and as sodium has a +1 charge, an electrical gradient also exists.
the "primary structure" of a protein refers to _____. (eText Concept 5.4) * interactions among the side chains or R groups of the amino acids * the α helix or β pleated sheets * the sequence of amino acids * coiling due to hydrogen bonding between amino acids * the weak aggregation of two or more polypeptide chains into one functional macromolecule
the sequence of amino acids
Which of the following statements about the sodium-potassium pump is correct? (eText Concept 7.4) * The sodium-potassium pump is a symporter that results in a net negative charge outside the cell. * The sodium-potassium pump transports Na+ and K+ across the plasma membrane in the same direction at the expense of ATP hydrolysis. * The sodium-potassium pump uses an existing proton gradient to drive the movement of sodium and potassium ions. * The sodium-potassium pump is an antiporter that results in a net negative charge inside the cell. * The sodium-potassium pump moves sodium out of the cell and co-transports protons into the cell, which is the source of energy for the movement of the potassium into the cell.
the sodium-potassium pump is an antiporter that results in a net negative charge inside the cell.
The rate of facilitated diffusion of a molecule across a membrane will increase as the concentration gradient of the molecule across the membrane increases to a certain point. Eventually, an increase in the concentration of the molecule will not cause any further increase in facilitated diffusion. This is because:
there are a limited number of carrier proteins in the membrane.
One characteristic shared by sucrose, lactose, and maltose is that _____. (eText Concept 5.2) * they are all disaccharides * they are all indigestible by humans * they are all polysaccharides * they all contain fructose
they are all disaccharides Correct. A disaccharide consists of two monosaccharides joined together by a glycosidic linkage.
Which of the following are pyrimidines found in the nucleic acid DNA? (eText Concept 5.5) * thymine and cytosine * guanine and cytosine * thymine and adenine * uracil and guanine * adenine and guanine
thymine and cytosine
Which of the following organisms groups includes carrier and channel proteins?
transport proteins
Which of the following types of membrane proteins are responsible for facilitated diffusion?
transport proteins
If you forget to water your favorite plant, all of the following will occur at a cellular level EXCEPT:
turgor pressure will build up in the cell.
What structure in the membrane causes plasma membrane to resist freezing?
unsaturated fatty acid tails
A plant cell adapted for waste storage would probably contain a large number of:
vacuoles
The Golgi apparatus packages materials into ____________ for transport and export.
vesicles
Which of the following "buds off" of the Golgi complex?
vesicles
Which of the following is the smallest?
virus
