Graduat Aptitude Exam

Each answer below includes 6 carbon atoms. Which choice has the highest amount of stored chemical energy? 6 molecules of CO2. 3 molecules of acetyl Co-A 2 molecules of pyruvate. 1 molecule of glucose.

1 molecule of glucose.

Substrate-level phosphorylation accounts for approximately what percentage of the ATP formed by the reactions of glycolysis? 0 percent 25 percent 50 percent 100 percent

100 percent

In a particular bird, feather color is controlled by two independently assorting genes, A and B. Whenever a dominant allele is present for either or both genes, blue color is produced. A cross of AaBb × AaBb would be expected to yield how many blue offspring out of 16? 1 3 9 15

15

If the isotope 32S has 16 protons and 16 neutrons, how many protons and how many neutrons will the isotope 35S have? 16 protons and 19 neutrons 19 protons and 16 neutrons 18 protons and 17 neutrons Can't be determined without more information

16 protons and 19 neutrons

Starting with one molecule of glucose, the energy-containing products of glycolysis are ________. 2 NAD+, 2 pyruvate, and 2 ATP 2 NADH, 2 pyruvate, and 2 ATP 2 FADH2, 2 pyruvate, and 4 ATP 6 CO2, 2 pyruvate, and 2 ATP

2 NADH, 2 pyruvate, and 2 ATP

Put the following steps of DNA replication in the proper order. 1. Single-stranded binding proteins attach to DNA strands. 2. Hydrogen bonds between base pairs of antiparallel strands are broken. 3. Primase binds to the site of origin. 4. DNA polymerase synthesizes new DNA. 5. An RNA primer is created.

2, 1, 3, 5, 4

Put the steps of the process of signal transduction in the order they occur: 1. A conformational change in the signal-receptor complex activates an enzyme. 2. Protein kinases are activated. 3. A signal molecule binds to a receptor. 4. Target proteins are phosphorylated. 5. Second messenger molecules are released.

3, 1, 5, 2, 4

Put the following events of prokaryotic transcription in the correct order. 1. Sigma binds to the promoter region. 2. The double helix of DNA is unwound, breaking hydrogen bonds between complementary strands. 3. Sigma binds to RNA polymerase. 4. Sigma is released. 5. Transcription begins.

3,1,2,5,4

If a double-stranded DNA molecule contains 20% thymine, what is the percentage of guanine? 20% 30% 40% 80% Can't be determined without more information.

30%

Somatic cells of the 9-banded armadillo (Dasypus novemcinctus) have 64 chromosomes. How many chromosomes are present in either the sperm or egg cells of the armadillo? None 32 64 128 You have to count them to know for sure.

32

What is the highest number of hydrogen bonds that a water molecule can participate in? 2 3 4 8

4

Nucleic acids are synthesized _____. 5' -> 3' only 3' -> 5' only Both 5' -> 3' and 3' -> 5' Only in the direction of the replication fork.

5' -> 3' only

If one strand of a DNA molecule has the sequence of bases 5'ATTGCA3', the other complementary strand would have the sequence ________. 5'TAACGT3' 5'TGCAAT3' 5'UAACGU3' 3'UAACGU5'

5'TGCAAT3'

When crossing an organism that is homozygous recessive for a single trait with a heterozygote, what is the chance of producing an offspring with the recessive phenotype? 0 percent 25 percent 50 percent 100 percent

50 percent

What is the structure of mitosis promoting factor (mpf)? A microtubule attached to a kinetochore. A cyclin protein bound to a cyclin-dependent kinase. Two chromatids attached at their centromeres. Rb protein bound to transcription factors.

A cyclin protein bound to a cyclin-dependent kinase.

What do we mean when we use the terms "monohybrid cross" and "dihybrid cross?" A monohybrid cross involves a single parent, whereas a dihybrid cross involves two parents. A monohybrid cross produces a single progeny, whereas a dihybrid cross produces two progeny. A dihybrid cross involves organisms that are heterozygous for two characters that are being studied, and a monohybrid cross involves organisms that are heterozygous for only one character being studied. A monohybrid cross is performed for one generation, whereas a dihybrid cross is performed for two generations.

A dihybrid cross involves organisms that are heterozygous for two characters that are being studied, and a monohybrid cross involves organisms that are heterozygous for only one character being studied.

Which of the following best describes a hypothesis? A hypothesis is like a blind guess. A hypothesis is a testable explanation for an observation. A hypothesis is proof of an idea. A hypothesis is a conclusion drawn from experiments.

A hypothesis is a testable explanation for an observation.

Which choice best defines an acid? A molecule that donates a proton to an aqueous solution. A molecule that absorbs protons from an aqueous solution. A molecule that is able to dissolve other substances. A molecule that forms hydrogen bonds with basic molecules.

A molecule that donates a proton to an aqueous solution.

Which of the following types of mutation would convert a proto-oncogene into an oncogene? A mutation that blocks transcription of the proto-oncogene. A mutation that creates an unstable proto-oncogene mRNA. A mutation that greatly increases the amount of the proto-oncogene protein. A deletion of most of the proto-oncogene coding sequence.

A mutation that greatly increases the amount of the proto-oncogene protein.

A super-repressor results from a mutation in the LacI (repressor) gene that turns the Lac genes off permanently. What type of a mutation would result in a super-repressor? A mutation that prevents repressor gene expression. A mutation that prevents the repressor from binding to the Lac operator. A mutation that prevents lactose from binding to the repressor. A mutation that causes the repressor to bind to its own promoter.

A mutation that prevents lactose from binding to the repressor.

What does the one-gene, one-enzyme hypothesis state? Genes are composed of stretches of DNA. A single gene codes for a single protein. Genes are made of protein. Genes code for mRNA.

A single gene codes for a single protein.

Which of the following best describes tertiary structure of RNA? A double-stranded helix A single nucleotide strand folded on itself in a "stem and loop" structure The sequence AUUGCUUC A single nucleotide strand where multiple "stem and loop" structures begin to interact

A single nucleotide strand where multiple "stem and loop" structures begin to interact

Which of the following is an example of potential energy? The moon in orbit around the Earth. Heat. Sound. Gas pressure in an unopened can of soft drink.

Gas pressure in an unopened can of soft drink.

In colorectal cancer, several genes must be mutated for a cell to develop into a cancer cell. Which of the following kinds of genes would you expect to be mutated? Genes coding for enzymes that act in the colon. Genes involved in control of the cell cycle. Genes that are especially susceptible to mutation. Genes of bacteria, which are abundant in the colon.

Genes involved in control of the cell cycle.

What is the difference between starch and glycogen? Starch is a storage polysaccharide, glycogen is structural. Starch forms from beta-glycosidic linkages, glycogen from alpha-glycosidic linkages. Glycogen is more highly branched than starch. The only difference is what type of organism they come from.

Glycogen is more highly branched than starch.

Which process does not occur within a mitochondrion in a eukaryotic cell? Glycolysis Pyruvate processing Citric acid cycle Electron transport and oxidative phosphorylation

Glycolysis

Sarah and Todd go to a new restaurant and do not like the food they are served. Their hypothesis is that if they go to the restaurant again, they will not like the food. If they continue to follow the scientific method, what should they do next? Never go near the restaurant again and tell all their friends to avoid it. Survey other customers to see if they like the food. Go back to the restaurant several times and order different items. Get some friends to go to the restaurant and order what Sarah and Todd didn't like.

Go back to the restaurant several times and order different items.

Which of the following is NOT involved in helping a cell deal with potentially toxic or unwanted compounds? Vacuole Peroxisome Golgi apparatus Lysosome

Golgi apparatus

Which organelle is responsible for processing, sorting, and shipping proteins to their final destination? Nucleus Lysosome Smooth endoplasmic reticulum Golgi apparatus

Golgi apparatus

If a cell were analogous to the city of Jacksonville, which organelle would perform the role of the post office? Nucleus Golgi complex Mitochondria Peroxisome Lysosome

Golgi complex

Which of the following are primarily responsible for cytokinesis in plant cells but not in animal cells? Kinetochores Golgi-derived vesicles Actin and myosin Centrioles and centromeres

Golgi-derived vesicles

Which of the following are purine nitrogenous bases? Cytosine and uracil Thymine and guanine Guanine and adenine Ribose and deoxyribose

Guanine and adenine

Which result led Mendel to the Principle of Independent Assortment? He observed a 3:1 ratio in the offspring of a monohybrid cross. He observed a 3:1 ratio in the offspring of a dihybrid cross. He observed a 9:3:3:1 ratio in the offspring of a dihybrid cross. He observed only one phenotype in the F1 generation when pure-line parents with two different phenotypes for a single trait were crossed.

He observed a 9:3:3:1 ratio in the offspring of a dihybrid cross.

Which of the following replication enzymes unwinds the parental DNA double helix? Topoisomerase Primase Ligase Helicase

Helicase

Which of the following is most critical for the association between histones and DNA? Histones are small proteins. Histones are highly conserved (i.e., histones are very similar in every eukaryote). Histones are positively charged. Histones are synthesized in the cytoplasm.

Histones are positively charged.

Which of the following happens at the conclusion of meiosis I? The chromosome number per cell remains the same. Sister chromatids are separated. Homologous chromosomes of a pair are separated from each other. Four daughter cells are formed.

Homologous chromosomes of a pair are separated from each other.

When describing an element, what does the atomic number tell you? How many protons are in each atoms nucleus. The combined number of protons and neutrons in the most common isotope of the element. The number of unshared electrons in the atoms outer shell? The number of electron shells used by the atom.

How many protons are in each atoms nucleus.

Which of the following terms is used to describe the offspring of a cross of two true-breeding parents that differ in one or more traits? Pure line Hybrid Homozygous Reciprocal

Hybrid

Which type of interaction stabilizes the α-helix and the β-pleated sheet structures of proteins? Hydrophobic interactions Disulfide bonds Ionic bonds Hydrogen bonds Peptide bonds

Hydrogen bonds

How is energy provided for the synthesis of peptide bonds in the ribosome? Ribosomes directly catalyze hydrolysis of ATP. The active site for peptide bonds is on elongation factors that use ATP for energy. Hydrolysis of the high-energy bond linking the amino acid to the tRNA. Peptide bond formation does not require energy input.

Hydrolysis of the high-energy bond linking the amino acid to the tRNA.

Which of the following is true of osmosis? Osmosis only takes place in red blood cells. Osmosis is and energy-dependent or "active" process. In osmosis, solutes move across a membrane from areas of lower water concentration to areas of higher water concentration. In osmosis, water moves across a membrane from areas of lower solute concentration to areas of higher solute concentration.

In osmosis, water moves across a membrane from areas of lower solute concentration to areas of higher solute concentration.

Where would you expect to find tight junctions? In the epithelium of an animal's intestine Between the smooth endoplasmic reticulum and the rough endoplasmic reticulum Between plant cells in a woody plant In the plasma membrane of prokaryotes

In the epithelium of an animal's intestine

Which of the following is not a condition required for natural selection to occur? Individuals with higher fitness live the longest. Individuals must vary in characteristics that are heritable. In particular environment, certain versions of heritable traits help individuals reproduce more than other versions. All of the statements are requirements of natural selection.

Individuals with higher fitness live the longest. Individuals must vary in characteristics that are heritable.

Most repressor proteins are allosteric. Which of the following binds with the repressor to alter its conformation? Inducer Promoter Ribosome RNA polymerase

Inducer

Which of the following, when taken up by a cell, binds to a repressor so that the repressor no longer binds to the operator? Inducer Promoter Repressor Co-repressor

Inducer

Which cellular activity is not primarily carried out by proteins? Signaling Transport Movement Information storage Catalysis

Information storage

As electrons are passed through the system of electron carriers associated with photosystem II, they lose energy. What happens to this energy? It excites electrons of the reaction center of photosystem I. It is lost as heat. It is used to establish and maintain a proton gradient. It is used to phosphorylate NAD+ to NADPH, the molecule that accepts electrons from photosystem I.

It is used to establish and maintain a proton gradient.

What is the energy carried in electrons from NADH used for in mitochondria? It is used to make glucose. It is used to pump protons. It is used to power ATP synthase. All choices are correct.

It is used to pump protons.

What can you infer about a high-molecular-weight protein that cannot be transported into the nucleus? It is too large. It lacks a nuclear localization signal. It contains errors in its amino acid sequence. It is unfolded.

It lacks a nuclear localization signal.

Which of the following must be true of a trait for natural selection to occur? It must be developed over the course of an organisms lifetime. It must be heritable. It must take hundreds of generations to occur. It must be better than the previous trait.

It must be heritable.

A bacterium is expelled from a warm human intestine into the cold world outside. How will this bacterium have to adjust its lipid bilayer if it is to survive in this new environment? It will increase the length and saturation of hydrocarbon chains in its phospholipids. It will decrease the length and saturation of the hydrocarbon chains in its phospholipids. It will decrease the length and increase the saturation of the hydrocarbon chains in its phospholipids. It will add more cholesterol molecules to the membrane.

It will decrease the length and saturation of the hydrocarbon chains in its phospholipids.

What is an organism's genotype? Its collection of genes. Its observable and measurable characteristics. Its environment. The number of chromosomes it has.

Its collection of genes.

Which of the following is an example of artificial selection? The long neck of a giraffe. Large breast muscles in turkeys. Adding length to the tail feathers of a widowbird. All choices are correct.

Large breast muscles in turkeys.

Which statement most accurately describes the consequences of loosening the tight junctions between epithelial cells? The middle lamella would be loosened and the connection between adjacent epithelial cells would be weakened. The flow of molecules from the cytoplasm of one epithelial cell to the cytoplasm of adjacent cells would increase. Transport of proteins through the plasma membrane of epithelial cells would increase. Leakage of ions and molecules between the inside and outside of the epithelial layer would become more likely.

Leakage of ions and molecules between the inside and outside of the epithelial layer would become more likely.

Which of the following replication enzymes joins Okazaki fragments together? Primase Helicase Ligase Polymerase

Ligase

Which of the following is not a property of life? Living things have the ability to store and use information. Living things have the ability to create energy. Living things undergo evolutionary adaptation. Living things have the ability to replicate

Living things have the ability to create energy.

Tay-Sachs disease is a fatal genetic abnormality that results in cells accumulating toxic amounts of complex, undigested lipids. Which organelle is involved with this condition? Endoplasmic reticulum Mitochondrion Lysosome Golgi apparatus

Lysosome

Which "equation" below most closely describes a condensation reaction? [M = monomer] M1 + M2 -> M1-M2 + H2O M1 + M2 + H2O -> M1-M2 M1-M2 + H2O -> M1 + M2 M1-M2 -> M1 + M2 + H2O

M1 + M2 -> M1-M2 + H2O

What "trigger" causes cells to pass the G1 checkpoint and enter S phase? MPF becomes activated. DNA is determined to be damaged. The Rb protein becomes phosphorylated. None of choices is correct.

MPF becomes activated.

Which choice is an important exception to the central dogma? DNA is the long-term storage molecule in all cells. mRNA is a short-lived information transfer molecule. Many genes code for RNAs that function directly in the cell. Proteins are responsible for most phenotype characteristics.

Many genes code for RNAs that function directly in the cell.

Crossing over normally takes place during which of the following processes? Meiosis I Meiosis II Mitosis Mitosis and meiosis I

Meiosis I

Which of the following is NOT a function of carbohydrates? Energy storage Cellular identity Membrane transport Cellular structure All choices are correct.

Membrane transport

Which answer correctly associates a distinctive event in mitosis with the mitotic phase when it occurs? Telophase: Sister chromatids separate. Metaphase: Chromosomes align at the cell equator. Anaphase: The nuclear envelope disappears. Prophase: Microtubules attach to kinetochores.

Metaphase: Chromosomes align at the cell equator.

Which of the following correctly matches a component of the cytoskeleton to one of its functions? Actin filaments form the nuclear lamina. Microtubules help animal cells divide into two. Intermediate filaments contribute to cytoplasmic streaming. Microtubules move chromosomes.

Microtubules move chromosomes.

Which structure—function pair is mismatched? Lysosome—intracellular digestion Ribosome—protein synthesis Golgi—protein trafficking Microtubule—muscle contraction

Microtubule—muscle contraction

Which type of DNA repair is most likely to be compromised if there is a failure in the system that allows repair enzymes to distinguish template and newly synthesized DNA? Mismatch repair. Nucleotide excision repair. Proofreading. Repair of UV damage.

Mismatch repair.

Which of the following does not contribute to genetic diversity? Mitosis Crossing over in meiosis Random alignment of chromosomes in meiosis All choices contribute to genetic diversity.

Mitosis

Which of the following is NOT a part of bacterial cell division? DNA replication Chromosome separation Mitosis Cytokinesis

Mitosis

Turner syndrome is characterized by the presence of only one X chromosome in an affected female. Which of the following accurately describes Turner syndrome? Monosomy Trisomy 2n + 1 Triploid

Monosomy

What does it mean when we say the genetic code is redundant? A single codon can specify the addition of more than one amino acid. The genetic code is different for different domains of organisms. The genetic code is universal (the same for all organisms). More than one codon can specify the addition of the same amino acid.

More than one codon can specify the addition of the same amino acid.

Which of the following is a function of the cytoskeleton? Synthesis of ATP. Photosynthesis in plant cells. Breakdown of macromolecules. Movement and organization of cell structures.

Movement and organization of cell structures.

Which of the following membrane activities requires energy from ATP? Facilitated diffusion of chloride ions across the membrane through a chloride channel. Movement of water into a cell. Movement of Na+ ions from a lower concentration in a mammalian cell to a higher concentration in the extracellular fluid. Movement of glucose molecules into a bacterial cell from a medium containing a higher concentration of glucose than that inside the cell.

Movement of Na+ ions from a lower concentration in a mammalian cell to a higher concentration in the extracellular fluid.

Which of the following statements about NAD+ is TRUE? NAD+ is reduced to NADH during glycolysis, pyruvate oxidation, and the citric acid cycle. NAD+ has more chemical energy than NADH. NAD+ can donate electrons for use in oxidative phosphorylation. In the absence of NAD+, glycolysis can still function.

NAD+ is reduced to NADH during glycolysis, pyruvate oxidation, and the citric acid cycle.

Which of the following is a product of glycolysis, pyruvate processing, and the citric acid cycle? ATP CO2 NADH Acetyl-CoA

NADH

The light-independent reactions of plants function to make organic molecules using carbon dioxide as a carbon source. What is the electron source that helps reduce carbon dioxide to sugars and other organic molecules? NADPH ATP Electrons from oxygen NADH

NADPH

A gene whose expression in turned off by the binding of a regulatory protein is said to be under what kind of regulation? Positive Negative Induction Repression

Negative

Which event in meiosis accounts for Mendel's principle of independent assortment? Nonhomologous chromosomes line up independently during meiosis I. Homologous chromosomes separate during meiosis I. Separation of sister chromatids occurs during meiosis II. Crossing over occurs between homologous chromosomes during meiosis I.

Nonhomologous chromosomes line up independently during meiosis I.

Which of the following statements is true about proteins? Peptide bonds are the only covalent bonds that can link together two amino acids in proteins. The polypeptide backbone is free to rotate about each peptide bond. The sequence of the atoms in the polypeptide backbone varies between different proteins. Nonpolar amino acids tend to be found in the interior of proteins.

Nonpolar amino acids tend to be found in the interior of proteins.

In addition to polysaccharides, monosaccharides are important for the structure of which other polymer? Nucleic acids Polypeptides None

Nucleic acids

Why did the F1 offspring of Mendel's classic pea cross always look like one of the two parental varieties? No genes interacted to produce the parental phenotype. Each allele affected phenotypic expression. The traits blended together during fertilization. One allele was dominant.

One allele was dominant.

Nucleic acids have definite polarity, or directionality. Stated another way, one end of the molecule is different from the other end. How are these ends described? One end has a hydroxyl group on the 2' carbon; the other end has a hydrogen atom on the 2' carbons. One end contains a nitrogenous base; the other end lacks it. One end has an unlinked 3' hydroxyl; the other end has an unlinked 5' phosphate. One end has one phosphate group; the other end has two phosphate groups.

One end has an unlinked 3' hydroxyl; the other end has an unlinked 5' phosphate.

Which choice describes an example of epistasis (gene interaction)? White-flowered snapdragons crossed with red-flowered snapdragons produce pink-flowered plants. The eye color gene of the fruit fly can produce many distinctive phenotypes. One gene in Labrador retrievers determines fur color, while another gene is needed to put color in the fur. All of the choices are examples of epistasis.

One gene in Labrador retrievers determines fur color, while another gene is needed to put color in the fur.

Semiconservative replication involves a template. What is the template? Single-stranded binding proteins DNA polymerase One strand of a DNA molecule An RNA molecule

One strand of a DNA molecule

Which amino acid is least likely to form hydrogen bonds with water or other polar molecules?

One with the least amount of COOH or OH bonds

Why is RNA considered most likely to be the precursor molecule to living cells? RNA is the easiest polymer to synthesize. Only RNA is capable of storing information and catalyzing reactions. DNA is too stable to store information efficiently. All choices are correct.

Only RNA is capable of storing information and catalyzing reactions. DNA is too stable to store information efficiently.

Which of the following is a difference between mitosis and meiosis? Genetic variation is only produced during mitosis. Only in meiosis do homologous chromosomes pair up. Chromosomes only replicate prior to the start of mitosis. Sister chromatids only separate during meiosis.

Only in meiosis do homologous chromosomes pair up.

Carbon dioxide (CO2) is released during which of the following stages of cellular respiration? Glycolysis and the oxidation of pyruvate to acetyl CoA The citric acid cycle and oxidative phosphorylation Oxidation of pyruvate to acetyl CoA and the citric acid cycle Fermentation and glycolysis

Oxidation of pyruvate to acetyl CoA and the citric acid cycle

Which of the following stages in the breakdown of the Cheerios® you had for breakfast generates the most ATP? The digestion of starch to glucose. Glycolysis. The citric acid cycle. Oxidative phosphorylation.

Oxidative phosphorylation.

In oxidative phosphorylation, ATP production is coupled to the events in the electron-transport chain. What is accomplished in the final electron transfer event in the electron-transport chain? OH- is oxidized to O2. Pyruvate is oxidized to CO2. Oxygen is reduced to H2O. NAD+ is reduced to NADH.

Oxygen is reduced to H2O.

Which of the following molecules contains at LEAST one peptide bond? Glycogen Cellulose Chitin Peptidoglycan

Peptidoglycan

Which of the following polysaccharides can form fibers in which individual polymers are covalently linked to one another? Glycogen Peptidoglycan Cellulose All polysaccharides can form covalently linked fibers

Peptidoglycan

Which of the following is NOT part of an amino acid? Amino group Phosphate group Carboxyl group Side chain/R group

Phosphate group

Which of the following statements best describes the relationship between photosynthesis and respiration? Respiration runs the biochemical pathways of photosynthesis in reverse. Photosynthesis occurs only in plants; respiration occurs only in animals. ATP molecules are produced in photosynthesis but not in aerobic respiration. Photosynthesis stores energy in complex organic molecules; respiration releases energy from complex organic molecules.

Photosynthesis stores energy in complex organic molecules; respiration releases energy from complex organic molecules.

Which statement is most accurate concerning how the molecular composition of a plant cell wall compares with the extracellular matrix of animal cells? In the plant cell wall, the "ground substance" surrounding the fibers contains carbohydrate; in the ECM it does not. Plant cell wall fibers consist primarily of carbohydrates; ECM fibers are dominated by proteins. The fibers in a plant cell wall are primarily proteins; ECM fibers are dominated by carbohydrates. Plant cell walls exhibit fundamentally different structural principles that ECM.

Plant cell wall fibers consist primarily of carbohydrates; ECM fibers are dominated by proteins.

Cystic fibrosis is caused by a single gene and affects the lungs, the pancreas, the digestive system, and other organs, resulting in symptoms ranging from breathing difficulties to recurrent infections. Which of the following terms best describes this? Incomplete dominance Pleiotropy Epistasis Codominance

Pleiotropy

A hydrogen bond results when which of the following conditions are met? Any covalent bond that includes a hydrogen atom. The atoms involved lose their valence electrons. Polar molecules interact through weak electrical attractions. One partner donates an electron to the other.

Polar molecules interact through weak electrical attractions.

Which feature is the best explanation for traits that show a continuous range of phenotypes, such as skin color in humans or kernel color in wheat? Crossing over in meiosis Incomplete dominance Sex-linked genes Polygenic inheritance

Polygenic inheritance

If a cell were analogous to the city of Jacksonville, what role would the mitochondria perform? Courthouse Power plant Post office Jacksonville International Airport Recycling center

Power plant

All of the following are differences between eukaryotes and prokaryotes except: Prokaryotes have a plasma membrane only, but eukaryotes have a plasma membrane and a nuclear membrane. Most bacteria and archaea are unicellular, but many eukaryotes are mulitcellular. Prokaryotes have a plasma membrane, while eukaryotes have only a nuclear membrane. Most prokaryotic cells are smaller than most eukaryotic cells.

Prokaryotes have a plasma membrane, while eukaryotes have only a nuclear membrane.

What is a major difference between eukaryotic DNA replication and prokaryotic DNA replication? Prokaryotic replication does not require a primer. Prokaryotic chromosomes have a single origin of replication, whereas eukaryotic chromosomes have multiple origins of replication. DNA replication in prokaryotic cells is conservative. DNA replication in eukaryotic cells is semiconservative. DNA polymerases of prokaryotes can add nucleotides to both 3' and 5' ends of DNA strands; those of eukaryotes function only in the 5' → 3' direction.

Prokaryotic chromosomes have a single origin of replication, whereas eukaryotic chromosomes have multiple origins of replication.

Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules? Lipids Glycogen Proteins Nucleic acids

Proteins

What would be the consequence of a defective aminoacyl-tRNA synthetase enzyme that could bind to three different amino acids? Protein synthesis would not occur. The ribosome would add an amino acid when a stop codon is in the A site. Proteins would be made with the wrong amino acid at some positions. The amino acid sequence of some proteins would be random.

Proteins would be made with the wrong amino acid at some positions.

Proto-oncogenes can change into oncogenes that cause cancer. Which of the following best explains the presence of these potentially harmful genes in eukaryotic cells? Proto-oncogenes first arose from viral infections. Proto-oncogenes normally help regulate cell division. Proto-oncogenes are genetic "junk." Proto-oncogenes are mutant versions of normal genes.

Proto-oncogenes normally help regulate cell division.

What is the difference between a purine & a pyrimadine?

Purine has a 5c-6c ring Pyrimidine only has a 5c ring

Which of the following is NOT a type of lipid? Triacylglycerol Steroid hormone Pyrimidine Beeswax

Pyrimidine

How does RNA differ from DNA? RNA contains uracil instead of cytosine. RNA contains uracil instead of thymine and it is usually single-stranded. RNA contains uracil instead of thymine and it is usually double-stranded. RNA contains thymine instead of uracil and it is usually single-stranded.

RNA contains uracil instead of thymine and it is usually single-stranded.

The phenomenon in which RNA molecules in a cell are destroyed if they have a sequence complementary to an introduced double-stranded RNA is called ________. RNA interference RNA obstruction RNA targeting retro-transcription

RNA interference

Which of the following is not a mechanism for signal amplification? Receptor binds multiple signal molecules. Intracellular enzymes synthesize second messengers. A phosphorylation cascade is activated. None - signals are never amplified.

Receptor binds multiple signal molecules.

Which of the following does NOT occur during mitosis? Condensation of the chromosomes Replication of the DNA Separation of sister chromatids Spindle formation

Replication of the DNA

Which of the following does not occur before a eukaryotic mRNA is exported from the nucleus? The mRNA is polyadenylated at its 3ʹ end. A 7-methyl-G cap is added to the 5' end of the mRNA. Ribosomes binds to the mRNA. Introns are removed.

Ribosomes binds to the mRNA.

Which structure is the site of the synthesis of proteins that will be exported from the cell? Rough endoplasmic reticulum Lysosomes Golgi apparatus Cytoplasmic ribosomes

Rough endoplasmic reticulum Lysosomes

In candy genetics, red m&m's (R) are dominant to yellow m&m's (r). You cross a red m&m with an unknown genotype (R?) with a true-breeding yellow m&m (rr). The following offspring are produced: 494 red m&m's, and 516 yellow m&m's. What was the genotype of your original red candy? RR Rr rr D. Can't tell without more information

Rr

Which of the following is NOT found in the thylakoid membrane? Antennae complex. ATP synthase enzyme. Rubisco, a Calvin cycle enzyme. Electron transport chain.

Rubisco, a Calvin cycle enzyme.

Which of the following is an example of polygenic inheritance? Pink flowers in snapdragons The ABO blood group in humans White and purple flower color in peas Skin pigmentation in humans

Skin pigmentation in humans

The liver is involved in detoxification of many poisons and drugs. Which of the following structures is primarily involved in this process and, therefore, abundant in liver cells? Rough ER Smooth ER Golgi apparatus Transport vesicles

Smooth ER

Which of the following is not an example of potential energy? Gas pressure in an unopened can of soft drink. Sound. Covalent bonds in glucose. A skier at the top of a hill.

Sound.

Where would you most likely find an integral membrane protein? On the inside surface of the cell membrane. On the outside surface of the cell membrane. Floating freely in the cytoplasm. Spanning the cell membrane, with parts of the protein visible from both the inside and the outside of the cell.

Spanning the cell membrane, with parts of the protein visible from both the inside and the outside of the cell.

Where do the enzymatic reactions of the Calvin cycle take place? Stroma of the chloroplast Thylakoid membranes Matrix of the mitochondria Cytosol

Stroma of the chloroplast

Which pathway do electrons take through the process of respiration? Carbon dioxide > oxygen > NADH > sugar Sugar > NADH > electron transport chain > oxygen Oxygen > electron transport chain > NADH > sugar Sugar > electron transport chain > NADH > oxygen

Sugar > NADH > electron transport chain > oxygen

Which pathway does carbon take through the process of respiration? Sugar to Krebs cycle to pyruvate to carbon dioxide Sugar to pyruvate to Krebs cycle to oxygen Sugar to pyruvate to Krebs cycle to carbon dioxide Sugar to pyruvate to oxygen to Krebs cycle

Sugar to pyruvate to Krebs cycle to carbon dioxide

What are the components of a nucleotide? Sugar, carboxyl group, phosphate group Sugar, aldehyde group, hydroxyl group Sugar, nitrogenous base, amino group Sugar, nitrogenous base, phosphate group

Sugar, nitrogenous base, phosphate group

What is the primary function of the Calvin cycle? Transport ribulose bisphosphate out of the cell. Synthesize simple sugars from carbon dioxide. Split water and release oxygen. All choices are correct.

Synthesize simple sugars from carbon dioxide.

All proteins that enter the nucleus share a similar sequence of amino acids that targets the protein to this site. True False

T

An ion gradient can serve as an energy source to move a solute across a membrane against its concentration gradient. True False

T

Damaged DNA can be repaired by removing the damaged nucleotides and resynthesizing the missing DNA. True False

T

Eukaryotic transcription requires the stepwise assembly of many proteins at the promoter in addition to RNA polymerase. True False

T

Fats store more energy that carbohydrates because they have more high-energy carbon-carbon and carbon-hydrogen bonds, and carbohydrates have more lower-energy carbon-oxygen bonds. True False

T

If you want to determine if the sex of a parent influences the transmission of a trait, you should do a reciprocal cross. True False

T

In the mitochondria, the potential energy of a proton gradient is first transformed to mechanical energy of a rotating enzyme subunit, and then into chemical bond energy of ATP. True False

T

Most cancer cells have defects in either growth signaling pathways or cell cycle control processes. True False

T

Of the major biological polymers, only polysaccharides can be branched. True False

T

The most energetically favorable structure for monosaccharides in cells is the ring form. True False

T

The process of cytokinesis occurs differently in plants and animals. True False

T

There may be many alleles for a particular trait, but any individual can only have two alleles. True False

T

Which statement is true about chromosomes in prokaryotic cells? The DNA is circular and supercoiled. The DNA is contained in many small pieces. The DNA is found in the cell nucleus. Prokaryotic cells do not have chromosomes.

The DNA is circular and supercoiled.

Which statement below best describes the S phase of the cell cycle? The DNA molecules are copied. The cell has a single copy of each chromosome. A period of growth and organelle synthesis. The cell divides into two daughter cells.

The DNA molecules are copied.

Which of the following statements about the Lac operon is false? The Lac repressor binds the operator when lactose is present in the cell. Even when the CAP activator is bound to DNA, if lactose is not present, the Lac operon will not be transcribed. The CAP activator can only bind DNA when it is bound to cAMP. The Lac operon only produces RNA when lactose is present and glucose is absent.

The Lac repressor binds the operator when lactose is present in the cell.

Which of the following would be used to differentiate between benign and malignant tumors? The formation of a cell mass Continued cell division A fast growth rate The ability to invade other tissues

The ability to invade other tissues

What activity would you have to engineer into DNA polymerase so that both new DNA strands could be made as leading strands, by following the replication fork? Synthesis without the need for a primer. The ability to proofread in the 5'->3' direction. The ability to synthesize DNA in the 3'->5' direction. The ability to synthesize DNA without using a template.

The ability to synthesize DNA in the 3'->5' direction.

What is the major structural difference between starch and glycogen? The types of monosaccharide subunits in the molecules The type of glycosidic linkages in the molecule Whether glucose is in the α or β form The amount of branching that occurs in the molecule

The amount of branching that occurs in the molecule

In the Morse code, a series of dots and dashes code for letters of the alphabet. How is this analogous to the genetic code? There is complementarity in the genetic code (A is complementary to T, and C is complementary to G). The bases that make up DNA are coded by the sugar-phosphate backbone. The machinery involved in DNA synthesis is analogous to the telegraph equipment used in sending Morse code. The bases of DNA code for the more complex amino acid sequence of the proteins in cells.

The bases of DNA code for the more complex amino acid sequence of the proteins in cells.

Which of the following is TRUE when comparing an uncatalyzed reaction to the same reaction with a catalyst? The catalyzed reaction will have the same ∆G. The catalyzed reaction will be slower. The catalyzed reaction will have higher activation energy. The catalyzed reaction will consume all of the catalyst.

The catalyzed reaction will have the same ∆G.

Some cells have several nuclei per cell. How could such multinucleated cells be explained? The cell underwent repeated cytokinesis but no mitosis. The cell underwent repeated mitosis with simultaneous cytokinesis. The cell underwent repeated mitosis, but cytokinesis did not occur. The cell had multiple S phases before it entered mitosis.

The cell underwent repeated mitosis, but cytokinesis did not occur.

What is an anticodon? The part of an mRNA that signals translation termination. The part of an mRNA that signals the start of translation. The part of a tRNA that binds to a codon in the mRNA. The part of a tRNA where the amino acid is attached.

The part of a tRNA that binds to a codon in the mRNA.

Which molecule or reaction supplies the energy for polymerization of nucleotides in the process of transcription? The interaction between RNA polymerase and the promoter The phosphate bonds in the nucleotide triphosphates that serve as substrates The energy released when hydrogen bonds are broken as the DNA molecule is unwound ATP

The phosphate bonds in the nucleotide triphosphates that serve as substrates

What is the difference between an aldose sugar and a ketose sugar? The number of carbons The position of the hydroxyl groups The position of the carbonyl group One is a ring form; the other is a linear chain

The position of the carbonyl group

How are the light-dependent and light-independent reactions of photosynthesis related? The products of light-independent reactions are used in light-dependent reactions. The products of light-dependent reactions are used in light-independent reactions. The products of light-independent reactions must be present for light-dependent reactions to take place. They are not related.

The products of light-dependent reactions are used in light-independent reactions.

Researchers found E. coli that had mutation rates 100 times higher than normal. Which of the following is the most likely cause of these results? The single-stranded binding proteins were malfunctioning. There were one or more mismatches in the RNA primer. The proofreading mechanism of DNA polymerase was not working properly. The DNA polymerase was unable to add bases to the 3' end of the growing nucleic acid chain.

The proofreading mechanism of DNA polymerase was not working properly.

Which statement below best describes what will happen if a properly folded, active protein is heated to 100°C (boiling)? The protein will become more active, because it has more energy. The protein will denature (unfold) because hydrogen bonds will fall apart. The primary sequence of the protein will be rearranged. Heating will have no effect on protein structure.

The protein will denature (unfold) because hydrogen bonds will fall apart.

Which of the following statements describes the F2 generation of a monohybrid cross? There will be an equal number of offspring exhibiting the dominant and recessive traits. All of the offspring will resemble the parent with the recessive trait. All of the offspring will resemble the parent with the dominant trait. The ratio of the offspring exhibiting the dominant and recessive traits will be 3:1.

The ratio of the offspring exhibiting the dominant and recessive traits will be 3:1.

Which event below occurs in anaphase of mitosis? The sister chromatids move opposite poles of the cell. Nuclear division is completed and cytokinesis occurs. The chromosomes align on the metaphase plate. The chromosomes begin to condense.

The sister chromatids move opposite poles of the cell.

Which of the following is the first event to take place in translation in eukaryotes? Elongation of the polypeptide Base pairing of activated methionine-tRNA to AUG of the messenger RNA Binding of the larger ribosomal subunit to smaller ribosomal subunits The small subunit of the ribosome recognizing and attaching to the 5' cap of mRNA

The small subunit of the ribosome recognizing and attaching to the 5' cap of mRNA

What is a kinetochore? The microtubule structure that separates chromosomes. Another name for condensed chromosomes. The structure on a chromosome where microtubules attach. The structure that pinches a cell in two during cytokinesis.

The structure on a chromosome where microtubules attach.

Why is it that RNA can catalyze reactions but DNA cannot? The primary structure of RNA is fundamentally different than the primary structure of DNA. The sugar of RNA is more reactive than the sugar of DNA. The bases of RNA are fundamentally different than the bases of DNA. RNA has more phosphate groups than DNA.

The sugar of RNA is more reactive than the sugar of DNA.

What feature of nucleotide monomers provides the energy needed for polymerization when nucleic acids are formed? Their methyl groups Their sugar groups Their nitrogenous bases Their phosphate groups

Their phosphate groups

Recent studies have shown that xeroderma pigmentosum (XP) (an error in the nucleotide excision repair process) can result from mutations in one of eight genes. What can you infer from this finding? There are eight genes that produce the same protein. These eight genes are the most easily damaged by ultraviolet light. There are several proteins involved in the nucleotide excision repair process. Eight types of DNA damage can be repaired by this system.

There are several proteins involved in the nucleotide excision repair process.

Which choice best describes the major role for hydrolysis reactions in cells? They are a key source of water. They build complex polymers from simple subunits. They add hydroxyl groups to carbon skeletons. They are responsible for the breakdown of complex molecules into simple subunits.

They are responsible for the breakdown of complex molecules into simple subunits.

What do alpha-helices and beta-sheets have in common? They represent the overall shape of a complete protein. They are both shaped like a coil. They are stabilized by hydrogen bonds on the peptide backbone. They are only found in enzymes.

They are stabilized by hydrogen bonds on the peptide backbone.

Which of the following structural features is common to cellulose, chitin, and peptidoglycan? They are all composed of glucose in either the α or the β form. They all contain peptide bonds. They can all form bonds between polymer chains that create parallel strands. They are all composed of highly branched fibers.

They can all form bonds between polymer chains that create parallel strands.

How do living organisms carry out reactions that require an input of energy? They can't; these reactions are impossible. They couple energy-requiring reactions to energy-releasing reactions. They use heat from energy-releasing reactions. Enzymes run energy-releasing reactions in reverse.

They couple energy-requiring reactions to energy-releasing reactions.

How do carbohydrates contain and/or display information for cells? They store information in the nucleus. They display information at the cell surface. They display information used by enzymes to bind to substrates. Carbohydrates have no role in information storage or display.

They display information at the cell surface.

The correct folding of proteins is necessary to maintain healthy cells and tissues. Unfolded proteins are responsible for such neurodegenerative disorders as Alzheimer's disease. What is the ultimate fate of these disease-causing, unfolded proteins? They are degraded. They bind a different target protein. They form protein aggregates. They are exported from the cell.

They form protein aggregates. They are exported from the cell.

Why are there several structurally different pigments in the reaction centers of photosystems? Excited electrons must pass through several pigments before they can be transferred to electron acceptors of the electron transport chain. They enable the plant to absorb more photons from light energy, all of which are at the same wavelength. This arrangement enables the plant to absorb light energy of a variety of wavelengths. They enable the reaction center to excite electrons to a higher energy level.

This arrangement enables the plant to absorb light energy of a variety of wavelengths.

In an experiment, investigators try to control all of the variables except one—the one that tests the hypothesis. Which of the following reasons is the primary rationale for controlling variables in an experiment? To enable investigators to repeat the test. To eliminate alternative explanations for the results of an experiment. To reduce statistical reliability. To create a control group.

To eliminate alternative explanations for the results of an experiment.

In sheep, white fleece is dominant to black. Which of the following situations is not possible? Two white sheep have white offspring. Two white sheep have black offspring. Two black sheep have white offspring. A white and a black sheep have two offspring, one white and one black.

Two black sheep have white offspring.

Which statement is correct regarding our current taxonomic system for naming organisms? Two different organisms never have the same genus and species names. The species name is the same for each organism in a genus. The genus name is different for two closely related species. Two different organisms have the same genus and species name if they are closely related.

Two different organisms never have the same genus and species names.

When nucleotides polymerize to form a nucleic acid, ________. a covalent bond forms between the sugar of one nucleotide and the phosphate of a second a hydrogen bond forms between the sugar of one nucleotide and the phosphate of a second covalent bonds form between the bases of two nucleotides a covalent bond forms between the sugar of one nucleotide and the base of a second

a covalent bond forms between the sugar of one nucleotide and the phosphate of a second

Termination of transcription in bacteria occurs when ________. the 5' cap structure on the nascent (new) RNA molecule loops back and interferes with RNA polymerase large and small subunits of the RNA polymerase dissociate a deoxyribonucleotide is base-paired to the 3' end of the transcript, signaling completion a hairpin secondary structure forms in the RNA transcript, and it separates from the RNA polymerase

a hairpin secondary structure forms in the RNA transcript, and it separates from the RNA polymerase

After making careful observations, scientists next develop ______. a conclusion a theory a hypothesis a set of data

a hypothesis

Pemphigus vulgaris is an autoimmune disorder in humans in which antibodies are produced against the proteins of desmosomes. The blistering of the skin and mucous membranes characteristic of this disorder is probably a result of ________. a decrease in flexibility of the cell membrane an inadequate number of G-protein receptors inadequate production of cytoskeletal proteins a loss in cell—cell adhesion

a loss in cell—cell adhesion

Cellulose is ________. a polymer composed of fructose monomers a storage polysaccharide for energy in plant cells used by plants to make glycogen a major structural component of plant cell walls

a major structural component of plant cell walls

The structure of a DNA molecule can be described as _____. a right-handed helix, identical base sequence on each strand, with anti-parallel strands a right-handed helix, complimentary base sequence on each strand, with anti-parallel strands a left-handed helix, identical base sequence on each strand, with parallel strands a right-handed helix, complimentary base sequence on each strand, with parallel strands

a right-handed helix, complimentary base sequence on each strand, with anti-parallel strands

Different cell types can respond differently to the same signaling molecule because___. different target cells have different sets of genes each cell type converts the signal to a different metabolite a target cell's response is determined by the components of its signal transduction pathways the circulatory system regulates responses to hormones by routing each hormone to the correct target cell

a target cell's response is determined by the components of its signal transduction pathways

The MPF protein complex turns itself off by _____. activating a process that destroys cyclin activating the anaphase-promoting complex binding to chromatin activating an enzyme that stimulates cyclin

activating a process that destroys cyclin

Reactants capable of interacting to form products in a chemical reaction must first overcome a thermodynamic barrier known as the reaction's ________. entropy equilibrium point free-energy content activation energy

activation energy

The biomass (dry weight) of a tree comes primarily from ______. water air soil fertilizer

air

Gene S controls the sharpness of spines in a type of cactus. Cactuses with the dominant allele, S, have sharp spines, whereas homozygous recessive ss cactuses have dull spines. At the same time, a second gene, N, determines whether or not cactuses have spines. Homozygous recessive nn cactuses have no spines at all. A cross between a true-breeding sharp-spined cactus and a spineless cactus would produce ________. all sharp-spined progeny 50 percent sharp-spined and 50 percent dull-spined progeny all spineless progeny It is impossible to determine the phenotypes of the progeny.

all sharp-spined progeny

Different versions of the same gene are called ______. traits homologs chromatids alleles

alleles

Feedback inhibition is an example of _______. a transition state active site competition covalent modification allosteric control

allosteric control

When binding of a molecule to a distant site on an enzyme changes the structure of the active site, it is referred to as _____. a transition state competition allosteric control free energy

allosteric control

Altering patterns of gene expression in prokaryotes would most likely serve an organism's survival by ________. organizing gene expression so that genes are expressed in a given order allowing each gene to be expressed an equal number of times allowing an organism to adjust to changes in environmental conditions allowing environmental changes to alter a prokaryote's genome

allowing an organism to adjust to changes in environmental conditions

In plant cells, the middle lamella ________. allows adjacent cells to adhere to one another prevents dehydration of adjacent cells maintains the plant's circulatory system allows for gas and nutrient exchange among adjacent cells

allows adjacent cells to adhere to one another

Phospholipids spontaneously form a lipid bilayer in aqueous solution because they are ___. enzymes hydrophobic amphipathic pathetic

amphipathic

Phosphorylation cascades involving a series of protein kinases are useful for cellular signal transduction because they ________. always lead to the same cellular response amplify the original signal many times counter the harmful effects of phosphatases use a small and fixed number of molecules

amplify the original signal many times

An atom that has a different number of electrons and protons is called _______. an ion radioactive polar inert

an ion

Scientists isolate cells in various phases of the cell cycle. They find a group of cells that have 1.5 times more DNA than G1 phase cells. The cells of this group ________. are in the G2 phase of the cell cycle are in the M phase of the cell cycle have just completed mitosis are in the S phase of the cell cycle

are in the S phase of the cell cycle

Both DNA and RNA ________. are information-containing molecules show primary, secondary, tertiary, and quaternary structure are highly reactive catalysts in cells naturally occur as a double helix

are information-containing molecules

Steroids are considered to be lipids because they ________. are essential components of cell membranes are not soluble in water are made of fatty acids are hydrophilic compounds

are not soluble in water are made of fatty acids

Starch and cellulose ________. are polymers of glucose are interchangeable can be digested by humans are used for energy storage in plants

are polymers of glucose

The organized microtubule structure that forms the basis of cilia and flagella is the _____. centriole vesicle nuclear pore axoneme

axoneme

Ribosomes can attach to prokaryotic messenger RNA ________. once posttranscriptional modification is complete before transcription is complete once replication is complete once the primary transcript has been released from RNA polymerase

before transcription is complete

In prokaryotes, ribosomes find the start site of translation by _______. scanning along the mRNA from the 5ʹ cap to the first AUG recognizing any AUG codon as the start of translation binding directly to a ribosome-binding site preceding the initiation codon binding an initiator tRNA

binding directly to a ribosome-binding site preceding the initiation codon

The tryptophan operator ________. is an allosteric protein binds to the tryptophan repressor when the repressor is bound to tryptophan is required for production of the mRNA encoded by the tryptophan operon is important for the production of the tryptophan repressor

binds to the tryptophan repressor when the repressor is bound to tryptophan

The ________ hypothesis would predict that when a black sheep and a white sheep mate, all their offspring would be gray. blending inheritance inheritance of acquired characteristics chromosomal inheritance autosomal inheritance

blending inheritance

Alternative RNA splicing ________. is a mechanism for increasing the rate of transcription can allow the production of proteins of different sizes and functions from a single mRNA can allow the production of similar proteins from different genes increases the rate of transcription

can allow the production of proteins of different sizes and functions from a single mRNA

Homologous chromosomes ____. are identical carry information for the same traits carry the same alleles pair up during mitosis

carry information for the same traits

The nucleus, an organelle found in eukaryotic cells, confines the __________, keeping them separated from other components of the cell. ribosomes chromosomes waste materials chemical reactions

chromosomes

Water molecules are attracted to other water molecules through hydrogen bonds. This property of water is called _____. adhesion cohesion surface tension dissociation

cohesion

Glyphosate (Roundup®) is a commonly used weed killer. It inhibits the enzyme EPSPS in plants. This enzyme joins two compounds to make a molecule required for amino acid synthesis. Glyphosate occupies the binding site of one of the two substrates. Glyphosate functions by ____. allosteric activation competitive inhibition feedback inhibition covalent modification

competitive inhibition

Operons ______. are commonly found in eukaryotic cells are transcribed by RNA polymerase II contain a cluster of genes transcribed as a single mRNA can only be regulated by gene activator proteins

contain a cluster of genes transcribed as a single mRNA

The primary structure of a protein is stabilized by _____. covalent bonds hydrogen bonds ionic bonds All choices are correct.

covalent bonds

Proteins that are involved in the regulation of the cell cycle and that show fluctuations in concentration during the cell cycle are called ________. ATPases kinetochores kinases cyclins

cyclins

During aerobic breakdown of glucose, glycolysis takes place in the ___, but most of the ATP is produced in the ___. nucleus; cytoplasm mitochondria; cytoplasm cytoplasm; mitochondria cytoplasm; nucleus

cytoplasm; mitochondria

Integrins are integral membrane proteins. They are often attached to ________. the membranes of intracellular organelles cytoskeletal proteins and proteins in the extracellular matrix the outside of the plasma membrane glycogen molecules and other types of cellular inclusions

cytoskeletal proteins and proteins in the extracellular matrix

According to the fluid‑mosaic model of membrane structure, proteins of the membrane are ___. spread in a continuous layer over the inner and outer surfaces of the membrane confined to the hydrophobic core of the membrane covalently attached to the phospholipids embedded in the lipid bilayer

embedded in the lipid bilayer

The advantage to the cell of the gradual oxidation of glucose during cellular respiration compared with its combustion to CO2 and H2O in a single step is that _______. more free energy is released for a given amount of glucose oxidized no energy is lost as heat energy can be extracted in usable amounts more CO2 is produced for a given amount of glucose oxidized

energy can be extracted in usable amounts

A eukaryotic DNA element that activates gene expression, can be located far from the promoter, and will function properly if moved or inverted is called a(n) __________. silencer operator TATA box enhancer

enhancer

The proper term used to describe disorder in energy transformations is ________. entropy free energy thermodynamics metabolism

entropy

Changes in DNA sequence from one generation to the next may result in offspring that are altered in fitness compared with their parents. The process of change and selection over the course of many generations is the basis of __________. mutation heredity evolution reproduction

evolution

Muscle cells differ from nerve cells mainly because they ________. express different genes contain different genes use different genetic codes have different chromosomes

express different genes

The predominant mechanism by which one cell differs from another is the difference in gene ________. expression sequences order replication

expression

Large polar molecules can diffuse into a cell, but only with the aid of a protein. This process is referred to as _____. osmosis facilitated diffusion active transport simple diffusion

facilitated diffusion

You are studying a system for transporting amino acids into cells and make the following observations: *The amino acids can move into or out of the cells, depending on the concentration gradient. *The amino acids are bound to a membrane protein during their passage through the membrane. *When ATP (energy) production by the cells is inhibited, transport of the amino acids is not affected. Based on the observations above, you conclude that the transport system is ___. active transport facilitated diffusion osmosis simple diffusion

facilitated diffusion

When the end-product of a biochemical pathway binds to and reduces the activity of an early enzyme in the pathway, the pathway is controlled by ____. feedback inhibition competitive inhibition product enhancement transition state activation

feedback inhibition

If a protein is unable to fold properly in a cell on its own, _______. peptide bonds will break it will cause nearby proteins to unfold it will never be able to function folding can be aided by molecular chaperones

folding can be aided by molecular chaperones

At the end of meiosis, there are ______.

four cells, genetically distinct from one another

One of the primary functions of RNA molecules is to ________. transmit genetic information to offspring make a copy of itself, thus ensuring genetic continuity function in the synthesis of proteins act as a pattern or blueprint to form DNA

function in the synthesis of proteins

Plasmodesmata are to plant cells, as ___________ are to animal cells. cell walls desmosomes tight junctions gap junctions

gap junctions

At the end of meiosis I, the chromosomal makeup of each daughter cell is ________. diploid, and the chromosomes are each composed of a single chromatid diploid, and the chromosomes are each composed of two chromatids haploid, and the chromosomes are each composed of a single chromatid haploid, and the chromosomes are each composed of two chromatids

haploid, and the chromosomes are each composed of two chromatids

Phospholipids and triglycerides (fats) both ____. contain serine or some other organic compound have three fatty acids have a phosphate have a glycerol backbone

have a glycerol backbone

Hormones are chemical substances produced in one organ that are released into the bloodstream and affect the function of a target organ. For the target organ to respond to a particular hormone, it must ________. modify its plasma membrane to alter the hormone entering the cytoplasm be from the same cell type as the organ that produced the hormone experience an imbalance that disrupts its normal function have receptors that recognize and bind the hormone molecule

have receptors that recognize and bind the hormone molecule

If you were to observe the activity of methylated DNA, you would expect it to ________. be replicating nearly continuously be unwinding in preparation for protein synthesis have turned off or slowed down the process of transcription be very actively transcribed and translated

have turned off or slowed

The greatest expression of the lac operon occurs when lactose levels are ______, and glucose levels are ________. low; low low; high high; low high; high

high; low

In a nucleosome, the DNA is wrapped around ________. ribosomes histones RNA the nucleus

histones

Large amounts of DNA in eukaryotic cells wrap around proteins called ________; this forms the ________ structure of DNA. purines: secondary pyrimidines; primary histones; primary histones; tertiary

histones; tertiary

The two strands of a DNA molecule are held together by ___. hydrogen bonds covalent bonds ionic bonds hydrophobic interactions

hydrogen bonds

Scientists isolate cells in various phases of the cell cycle. They find a group of cells that have 1.5 times more DNA than G1 phase cells. The cells of this group are ________. in the G2 phase of the cell cycle in the M phase of the cell cycle in the S phase of the cell cycle just completing mitosis

in the S phase of the cell cycle

Palominos are a breed of horse that has a light brown color. They are produced by crossing true-breeding "Cremello" (white) horses with true-breeding dark-colored "Chestnuts". This phenotypic relationship is an example of ____. complete dominance incomplete dominance codominance blending

incomplete dominance

The electron transport chain is located predominantly in the ___. outer membrane of the mitochondria intermembrane space of the mitochondria inner membrane of the mitochondria cytoplasm of the cell

inner membrane of the mitochondria

A nonsense mutation in a gene ________. changes an amino acid in the encoded protein has no effect on the amino acid sequence of the encoded protein introduces a premature stop codon into the mRNA alters the reading frame of the mRNA

introduces a premature stop codon into the mRNA

A G-protein with GTP bound to it ________. is in its active state signals a protein to maintain its shape and conformation will use cGMP as a second messenger directly affects gene expression

is in its active state

The double-helical DNA molecule ______. serves as a template for protein synthesis is used to synthesize messenger RNA contains two identical single strands of DNA must be accurately copied to ensure variation in organisms

is used to synthesize messenger RNA

Two atoms that have the same number of protons and electrons, but different numbers of neutrons are called ______. elements isotopes compounds inert

isotopes

The general name for an enzyme that transfers phosphate from ATP to a protein is _____. kinase receptor activator There is no such enzyme.

kinase

Lipids that contain a high number of double bonds in their fatty acid chains will ________. contain more hydrogens than lipids that contain few double bonds in their fatty acid chains pack very tightly together at room temperature likely be liquid at room temperature have more carbons that rotate freely than lipids that contain few double bonds in their fatty acid chains

likely be liquid at room temperature

Glycolysis is active when cellular energy levels are ____; the regulatory enzyme, phosphofructokinase, is ____ by ATP. low; activated low; inhibited high; activated high; inhibited

low; inhibited

The mechanism used by enzymes to catalyze reactions is to ______. concentrate the reactants so the reaction goes faster lower the energy of activation for the reaction convert energy requiring reactions to energy releasing reactions provide a source of electrons for forming covalent bonds

lower the energy of activation for the reaction

According to the central dogma, what molecule should go in the blank? DNA → ________ → Proteins mtDNA mRNA tRNA rRNA

mRNA

Which of the following statements about transcription is false? A new RNA molecule can begin to be synthesized from a gene before the previous RNA molecule's synthesis is completed. If two genes are to be expressed in a cell, these two genes can be transcribed with different efficiencies. RNA polymerase is responsible for both unwinding the DNA helix and catalyzing the formation of the phosphodiester bonds between nucleotides. mRNAs must fold into a cloverleaf structure in order for translation to occur.

mRNAs must fold into a cloverleaf structure in order for translation to occur.

A point mutation that alters the amino acid sequence of a protein is called a ____ mutation. nonsense missense frameshifrt inversion

missense

The mutation resulting in sickle cell disease changes one base pair of DNA so that a codon now codes for a different amino acid, making it an example of a ________. nonsense mutation frameshift mutation silent mutation missense mutation

missense mutation

Sister chromatids separate from each other during ________. mitosis only meiosis I only meiosis II only mitosis and meiosis II

mitosis and meiosis II

Plants produce more seeds when they reproduce asexually than sexually. Yet most plants reproduce sexually in nature. What is the probable explanation for the prevalence of sexual reproduction? Sexual reproduction ________. is more energy efficient than asexual reproduction ensures genetic continuity from parents to offspring mixes up alleles, contributing to variation in a species is not dependent on other agents of pollination

mixes up alleles, contributing to variation in a species

A protein that uses energy from ATP hydrolysis to move along cytoskeleton tracks is called a _____ . receptor centriole motor protein filament

motor protein

If a nondisjunction event occurred in meiosis II, you would expect the four resulting gametes to have which of the following chromosome sets (where n = haploid chromosome number)? n, n, n, n n, n, n + 1, n - 1 n + 1, n + 1, n - 1, n - 1 n, n, n, n + 1

n, n, n + 1, n - 1

Kleinfelter syndrome results in males with an extra X chromosome (they have 22 pairs of autosomes, plus XXY). This situation results from ______. rossing over of non-sister chromatids independent assortment mutation non-disjunction

non-disjunction

DNA wrapped around a core of histone proteins is called a _______. chromatin chromosome 30nm fiber nucleosome

nucleosome

By definition, prokaryotic cells do not possess __________. a nucleus membranes ribosomes replication machinery

nucleus

Step 3 in glycolysis requires the activity of the enzyme phosphofructokinase to convert fructose 6-phosphate into fructose 1,6-bisphosphate. Which of the following molecules is an allosteric inhibitor of this enzyme? Phosphate NAD+ ADP ATP

ATP

The light reactions of photosynthesis supply the dark reactions (Calvin cycle) with ___. H2O and NADP+ CO2 and ATP sugar and O2 ATP and NADPH

ATP and NADPH

How does the sodium/potassium pump work? It is a stationary channel that is opened using the energy of ATP hydrolysis. It uses the energy of the sodium gradient to move potassium, and the gradient of potassium to move sodium. ATP binding and hydrolysis drive changes in the protein's structure to move ions against their concentration gradients. None of the choices is correct.

ATP binding and hydrolysis drive changes in the protein's structure to move ions against their concentration gradients.

The oxygen consumed during cellular respiration is involved directly in which process or event? Glycolysis Accepting electrons at the end of the electron transport chain The citric acid cycle The phosphorylation of ADP to form ATP

Accepting electrons at the end of the electron transport chain

Which of the following is an aspect of regulation of the trp operon that is NOT involved in regulation of the lac operon? Regulation by a repressor Allosteric regulation of a repressor Activation of a repressor by a co-repressor Binding of a repressor to an operator

Activation of a repressor by a co-repressor

Imagine an enzyme-catalyzed reaction proceeding under typical conditions for that enzyme. Which of the following should you do to increase the rate of the reaction? Add more substrate. Add more product. Increase the temperature by 20°C. Change the pH.

Add more substrate

A common feature of the proteins found in the plasma membrane is that they: contain hydrophobic amino acids where they cross the lipid bilayer. often have carbohydrates attached. can move within the lipid bilayer. All choices are correct.

All choices are correct.

Both cellulose and chitin form strong, structural fibers. What do these two polymers have in common? They are linked by beta-1,4 linkages. Parallel strands are held together into fibers by hydrogen bonds between strands. Both are composed of a single type of monomer. All choices are correct.

All choices are correct.

The tertiary structure of a protein is stabilized by _________ . hydrogen bonds disulfide bonds ionic interactions hydrophobic interactions All choices are correct.

All choices are correct.

Which choice describes a common property of both the mitochondrial inner membrane and the chloroplast thylakoid membrane? Transport of electrons through and electron transport chain. Protons are pumped across the membrane. The membrane contains ATP synthase. All choices are correct.

All choices are correct.

Which choice is correct regarding the differences between starch and cellulose? Starch is a polymer of alpha-glucose; cellulose is a polymer of beta-glucose. Starch functions to store energy; cellulose is a structural molecule. Starch is readily digested by most animals; cellulose is highly resistant to digestion. All choices are correct.

All choices are correct.

Which of the following events occurs in meiosis but not mitosis? Crossing over of non-sister chromatids. Pairing of homologous chromosomes at the metaphase plate. Two consecutive cell divisions. All choices are correct.

All choices are correct.

Which of the following features determines whether a cell moves past the G1 cell cycle checkpoint? Whether the DNA is healthy or damaged. Whether or not the cell is large enough with enough organelles for two cells. The presence or absence of signal molecules that promote cell division. All choices are correct.

All choices are correct.

Which of the following is true of monosaccharides? They have three or more carbons. They are either aldehydes or ketones. They contain two or more hydroxyl groups. All choices are correct.

All choices are correct.

Which of the following is true of protein folding? A properly folded protein is at is lowest energy. Proper folding results in the highest number of non-covalent interactions. Protein folding follows a hierarchical process. All choices are correct.

All choices are correct.

Which of these steps in gene expression is unique to eukaryotes? Chromatin remodeling RNA processing Control of mRNA stability All choices are correct.

All choices are correct.

Which organelle has more than one lipid bilayer? Mitochondria Nucleus Chloroplast All choices are correct.

All choices are correct.

Which activity is NOT carried out by DNA polymerase during DNA replication? Synthesis of new DNA. Repair of mistakes by proofreading. Removal of RNA primers. All of these functions are carried out by DNA polymerase.

All of these functions are carried out by DNA polymerase.

Which of the following allows more than one type of protein to be produced from one gene? Alternative forms of chromatin remodeling. Alternative mRNA splicing. Use of different RNA polymerases. Use of different types of ribosomes.

Alternative mRNA splicing.

In cells, membrane proteins are responsible for the passage of substances that can't cross the membrane on their own. Channels and transporters are involved in facilitated diffusion. Pumps are involved in active transport. In terms of their properties or functions, which statement most accurately describes how these three types of membrane proteins compare? Channels and transporters are integral membrane proteins; pumps are peripheral membrane proteins. Among the three types, only pumps can concentrate substances on one side of the membrane. Among the three types, only pumps are thought to undergo a shape change as part of their function. Pumps are selective; channels and transporters are not selective.

Among the three types, only pumps can concentrate substances on one side of the membrane.

What event accompanies energy absorption by chlorophyll (or other pigment molecules of the antenna complex)? ATP is synthesized from the energy absorbed. A carboxylation reaction of the Calvin cycle occurs. NADPH is oxidized. An electron is excited.

An electron is excited.

Which of the following is the best explanation for why cholesterol decreases the permeability of biological membranes? Cholesterol binds to the outside surface of a membrane, thus blocking the movement of solutes. Because cholesterol is amphipathic, it forms tiny vesicles that trap solutes. Because cholesterol is amphipathic, it fits in between the phospholipids and blocks diffusion through the membrane. Cholesterol has four rings in its structure that can "trap" solutes.

Because cholesterol is amphipathic, it fits in between the phospholipids and blocks diffusion through the membrane.

An activated receptor tyrosine kinase transduces a signal by which mechanism? Activation of G-proteins. Synthesis of second messengers. Binding bridge proteins and activating Ras. All choices are possible.

Binding bridge proteins and activating Ras.

Which statement is correct regarding prokaryotes versus eukaryotes? Only prokaryotes have a cell wall. Only eukaryotes have a cell wall. Both prokaryotes and eukaryotes have internal membrane compartments. Both prokaryotes and eukaryotes have a plasma membrane

Both prokaryotes and eukaryotes have a plasma membrane

Which of the following statements about membrane structure is true? All membranes have essentially the same structure and function. Variation in lipid composition determines a membrane's function; proteins only perform a structural role. All membranes have the same lipid composition, so function is determined by the proteins that are present. Both the lipid and protein composition can vary between membranes and contribute to function.

Both the lipid and protein composition can vary between membranes and contribute to function.

Which bond is a peptide bond? NH2-CRH CRH-CO2 CO2-NHR NHR-CRH CR2H-CO2

CO2-NHR

Which molecule would most rapidly pass through a plasma membrane by simple diffusion? Water Carbon dioxide Glucose Sodium ion

Carbon dioxide

Which two functional groups are always found in amino acids? Ketone and methyl groups Carbonyl and amino groups Carboxyl and amino groups Amino and sulfhydryl groups Hydroxyl and carboxyl groups

Carboxyl and amino groups Amino and sulfhydryl groups

What is the term for metabolic pathways that release stored energy by breaking down complex molecules? Anabolic pathways Catabolic pathways Thermodynamic pathways Bioenergetic pathways

Catabolic pathways

Activated signal receptors on the plasma membrane can carry out which two activities? Make second messengers; activate gene expression Activate G proteins; activate gene expression Catalyze receptor phosphorylation; activate G proteins Make second messengers; catalyze phosphorylation

Catalyze receptor phosphorylation; activate G proteins

Bacterial and eukaryotic cells primarily control gene expression at the level of transcription. If instead cells exerted control of gene expression primarily at the post-translational level, what would be different? The ability to rapidly respond to environmental change would be reduced. Cells would expend significantly more energy. Genes would no longer be transcribed. Translation of mRNA into protein would not occur.

Cells would expend significantly more energy.

In what way do the membranes of a eukaryotic cell vary? Phospholipids are found only in certain membranes. Certain proteins are unique to each membrane. Only certain membranes of the cell are selectively permeable. Some membranes have hydrophobic surfaces exposed to the cytoplasm, while others have hydrophilic surfaces facing the cytoplasm.

Certain proteins are unique to each membrane.

Which choice describes the cycle of events for each new amino acid during translation elongation? Small ribosome subunit binds mRNA; initiator tRNA binds; large ribosome subunit binds. Charged tRNA enters A site; peptide bond is formed; ribosome translocates. Ribosome translocates; peptide bond is formed; new tRNA enters E site. Stop codon is in A site; release factor enters E site; polypeptide is released

Charged tRNA enters A site; peptide bond is formed; ribosome translocates.

How are amino acid side chains usually classified? Small, medium, or large. Straight, branched, or rings. Charged, polar, non-polar. Reactive or non-reactive.

Charged, polar, non-polar.

Inside an active mitochondrion, most electrons follow which pathway? Glycolysis → NADH → oxidative phosphorylation → ATP → oxygen Citric acid cycle → FADH2 → electron transport chain → ATP Pyruvate → citric acid cycle → ATP → NADH → oxygen Citric acid cycle → NADH → electron transport chain → oxygen

Citric acid cycle → NADH → electron transport chain → oxygen

The drug cytochalasin B blocks the function of actin. Which of the following aspects of the cell cycle would be most disrupted by cytochalasin B? Spindle formation Spindle attachment to kinetochores DNA synthesis Cleavage furrow formation and cytokinesis

Cleavage furrow formation and cytokinesis

Which of the following terms would not be used in a description of the cytoskeleton? Microtubule Actin filament Collagen Intermediate filament

Collagen

Which of the following would you NOT find in a plant cell? Pectin Polysaccharides Collagen Lignin

Collagen

The drug Tamiflu prevents the influenza virus from infecting your cells. It is very similar in structure to the substrate for the enzyme neuraminidase on the surface of the virus. Tamiflu most likely works by which mechanism? Allosteric activation Allosteric inhibition Competitive inhibition Noncompetitive inhibition

Competitive inhibition

What is the structural feature that allows DNA to replicate? The repeating sugar-phosphate backbone Complementary pairing of the nitrogenous bases Twisting of the molecule to form an α-helix Three-component structure of the nucleotides

Complementary pairing of the nitrogenous bases

Motor proteins provide for molecular motion in cells by interacting with which cellular structures? Mitochondria and chloroplasts Membrane proteins of the nuclear envelope Cytoplasmic and endoplasmic reticulum-bound ribosomes Components of the cytoskeleton

Components of the cytoskeleton

A sulfur atom has 16 protons and 16 electrons. If you add a proton to a sulfur atom, what have you done? Created an isotope of sulfur. Created a positively charged ion of sulfur. Created a negatively charged ion of sulfur. Converted the atom into a different element.

Converted the atom into a different element.

Which of the following includes all of the pyrimidines found in RNA and DNA? Cytosine and uracil Cytosine and thymine Cytosine, uracil, and thymine Uracil, adenine, and guanine

Cytosine, uracil, and thymine

If radioactive thymine is added to a cell culture growth medium, which cellular molecules will be radioactively labeled? Proteins RNA DNA Both RNA and DNA

DNA

If you wanted to prevent a regulatory protein from changing gene expression, you would have to prevent physical contact between the protein and ________. ribosomes DNA mRNA other proteins

DNA

In eukaryotic cells, chromosomes are composed of ________. DNA only DNA and RNA DNA and proteins DNA and phospholipids

DNA and proteins

Genotype is to ________ as phenotype is to ________. DNA base sequence; physical traits that are products of the proteins produced heredity; DNA base sequence gene regulation; translation transcription; amino acid sequence

DNA base sequence; physical traits that are products of the proteins produced

In trying to determine whether DNA or protein is the genetic material, Hershey and Chase made use of which of the following facts? DNA contains sulfur, whereas protein does not. DNA contains phosphorus, whereas protein does not. DNA contains nitrogen, whereas protein does not. RNA includes ribose sugars, whereas DNA includes deoxyribose sugars.

DNA contains phosphorus, whereas protein does not.

When does DNA replication take place regarding meiosis? DNA replication does not take place in cells destined to undergo meiosis. DNA replication occurs before meiosis I begins. DNA replication occurs between meiosis I and meiosis II. DNA replication occurs prior to both meiotic cell divisions.

DNA replication occurs before meiosis I begins.

Transcription describes the transfer if information from ____ to ____. DNA; RNA RNA; DNA RNA; protein DNA; protein

DNA; RNA

You have isolated nucleic acid from a cell. How can you tell if it is RNA or DNA? Determine whether or not it has phosphate groups. Determine if it has double-stranded regions. Determine its base composition. Determine its polarity.

Determine its base composition.

Which of the following is NOT a function of mitosis? Growth and development of multicellular organisms. Reproduction of single celled organisms. Development of sperm and egg cells. Tissue growth and repair.

Development of sperm and egg cells.

If cells of an individual contain the same set of genes, how do these cells become different from each other during development? Different cell type-specific regulatory elements in DNA are created during development. Different cell type-specific regulatory elements in DNA are selectively lost during development. Differences in extracellular signals received by each cell lead to differences in the types of regulatory proteins present in each cell. Differences develop in promoter s

Differences in extracellular signals received by each cell lead to differences in the types of regulatory proteins present in each cell.

What is the most likely fate of a bacterial cell engulfed by phagocytosis? Storage in a vacuole. Escape from the cell. Digestion in a lysosome. Sorting its components in the Golgi apparatus.

Digestion in a lysosome.

Which of the following can occur by the process of meiosis but not mitosis? Haploid cells fuse to form diploid cells. Haploid cells multiply into more haploid cells. Diploid cells form haploid cells. Haploid cells form diploid cells.

Diploid cells form haploid cells.

Which choice is the most inclusive category of organisms? Domain Phylum Species Genus

Domain

Which of the following most accurately describes what is happening along the electron transport chain during aerobic respiration? Electrons are transferred to ADP to generate ATP at each step in the process. Each electron carrier alternates between being reduced and being oxidized. Key molecules move through multiprotein complexes. Energy of the electrons increases at each step of the process.

Each electron carrier alternates between being reduced and being oxidized.

Eukaryotic telomeres replicate differently than the rest of the chromosome. This is a consequence of which of the following? The evolution of telomerase enzyme. DNA polymerase that cannot replicate the leading strand template to its 5' end. Gaps left at the 5' end of the lagging strand. Circular chromosomes contain no ends.

Gaps left at the 5' end of the lagging strand.

Carrier proteins release their cargo molecules ________. on the side of the membrane that has a lower concentration of the cargo molecule on the side of the membrane that has a higher concentration of the cargo molecule immediately after a phosphate has been added to the carrier protein immediately after a phosphate has been removed from the carrier protein

on the side of the membrane that has a lower concentration of the cargo molecule

Okazaki fragments are found ______. only on the leading strand only at the origin of replication only in front of the replication fork only on the lagging strand

only on the lagging strand

One key difference between plant cells and animal cells is that ____. only animal cells have membranes only plant cells have cell walls osmosis only occurs in plant cells only plant cells have mitochondria

only plant cells have cell walls

When a glucose molecule loses a hydrogen atom as the result of an oxidation—reduction reaction, the molecule becomes ________. hydrolyzed hydrogenated oxidized reduced

oxidized

Water molecules are polar because _________. most water exists at the north and south poles. electrons are shared equally by oxygen and hydrogen. oxygen is more electronegative than hydrogen. the atoms that make up a water molecule are held together by hydrogen bonds.

oxygen is more

A white blood cell engulfing a bacterium is an example of ___. phagocytosis receptor-mediated endocytosis facilitated diffusion exocytosis

phagocytosis

Pasteur's experiments proved that ________. cells cannot survive in swan-necked flasks in order to grow, cells need to be supplied with oxygen spontaneous generation can only occur if nutrient broth is left open to the environment preexisting cells present in the air can grow in sterilized nutrient broth

preexisting cells present in the air can grow in sterilized nutrient broth

Telomerase is needed to ______. synthesize telomere proteins prevent the loss of DNA bases at the ends of linear chromosomes create repetitive DNA sequences that allow the assembly of the kinetochore open the two strands of DNA in front of the replication fork

prevent the loss of DNA bases at the ends of linear chromosomes

A mutant bacterial cell has a defective aminoacyl-tRNA synthetase that attaches a lysine to tRNAs with the anticodon AAA instead of the normal phenylalanine. The consequence of this for the cell will be that _____. the cell will compensate for the defect by attaching phenylalanine to tRNAs with lysine- specifying anticodons proteins in the cell will include lysine instead of phenylalanine at amino acid positions specified by the codon UUU none of the proteins in the cell will contain phenylalanine the ribosome will skip a codon every time a UUU is encountered

proteins in the cell will include lysine instead of phenylalanine at amino acid positions specified by the codon UUU

At the end of glycolysis, each molecule of glucose has yielded 2 molecules of _______, 2 molecules of ________, and a net of 2 molecules of _________. FAD, NAD+, ADP CO2, NAD+, ADP lactic acid, ethanol, CO2 pyruvate; NADH; ATP

pyruvate; NADH; ATP

Transfer RNA (tRNA) molecules _____. read the message in mRNA and carry amino acids to ribosomes carry genetic information from DNA to protein catalyze the formation of peptide bonds in a growing protein chain consist of large and small subunits

read the message in mRNA and carry amino acids to ribosomes

The sigma subunit of bacterial RNA polymerase __________. contains the catalytic activity of the enzyme remains part of the polymerase throughout transcription recognizes promoter sites in the DNA recognizes transcription termination sites in the DNA

recognizes promoter sites in the DNA

The primary purpose of fermentation is to ______. permit ATP synthesis in the presence of excess oxygen remove toxic pyruvate from the cell regenerate NAD+ from NADH allowing glycolysis to continue produce amino acids for protein synthesis

regenerate NAD+ from NADH allowing glycolysis to continue

The mitotic spindle is a microtubular structure that is involved in ________. splitting of the cell (cytokinesis) following mitosis triggering the compaction and condensation of chromosomes disassembly of the nuclear membrane separation of sister chromatids

separation of sister chromatids

The reason for differences in the sets of proteins expressed in a nerve and a pancreatic cell of the same individual is that nerve and pancreatic cells contain different ________. genes regulatory DNA sequences sets of regulatory proteins promoters

sets of regulatory proteins promoters

Which of the following is NOT used in protein synthesis? snRNP ribosome amino acids tRNA

snRNP

If red blood cells are placed in distilled water ____. so much water will enter the cells that they will burst so much water will leave the cells that they will shrivel up water will move equally in both directions across the membrane nothing will happen

so much water will enter the cells that they will burst

When oxygen is released as a result of photosynthesis, it is a direct by-product of ________. reducing NADP+ splitting water molecules chemiosmosis the electron transfer system of photosystem I

splitting water molecules

The receptors for steroid hormones are located inside the cell instead of on the membrane surface like most other signal receptors. This is NOT a problem for steroids because ________. the receptors can be readily stimulated to exit and relocate on the membrane surface steroids do not directly affect cells but instead alter the chemistry of blood plasma steroid hormones are lipid soluble, so they can readily diffuse through the lipid bilayer of the cell membrane teroids must first bond to a steroid activator, forming a complex that then binds to the cell surface

steroid hormones are lipid soluble, so they can readily diffuse through the lipid bilayer of the cell membrane

In chloroplasts, chemiosmosis moves protons from the ________. stroma to photosystem II matrix to the stroma stroma to the thylakoid space intermembrane space to the matrix

stroma to the thylakoid space

Catabolic pathways ________. combine molecules into more energy-rich molecules supply energy for the cell's work are spontaneous and do not need enzyme catalysis in living systems build up complex molecules such as protein from simpler compounds

supply energy for the cell's work

A newly discovered herbicide makes the thylakoid membrane permeable to protons. Use of this chemical will have the most direct impact on the ____. splitting of water absorption of light energy by chlorophyll flow of electrons from photosystem II to photosystem I synthesis of ATP

synthesis of ATP

The key purpose of any single experiment is to _____. prove whether a hypothesis is right or wrong answer as many questions as possible test a hypothesis to see if the evidence supports it obtain accurate experimental results

test a hypothesis to see if the evidence supports it

Some photosynthetic organisms contain chloroplasts that lack photosystem II, yet they are able to survive. The best way to detect the lack of photosystem II in these organisms would be to ________. determine if they have thylakoids in the chloroplasts test for liberation of O2 in the light test for CO2 fixation in the dark test for production of either sucrose or starch

test for liberation of O2 in the light

In the polymerization of DNA, a phosphodiester bond is formed between a phosphate group of the nucleotide being added and ________ of the last nucleotide in the polymer. the 5' phosphate carbon #6 the 3' -OH a nitrogen from the nitrogen-containing base

the 3' -OH

A solution of starch at room temperature does NOT readily decompose to form a solution of simple sugars because ________. the starch solution has less free energy than the sugar solution the hydrolysis of starch to sugar is endergonic the activation energy barrier for this reaction cannot easily be surmounted at room temperature starch hydrolysis is nonspontaneous

the activation energy barrier for this reaction cannot easily be surmounted at room temperature

A peptide bond forms between ____. the central alpha carbons on each amino acid the side chains on each amino acid the amino groups on each amino acid the amino group of one amino acid and the carboxyl group of the other amino acid

the amino group of one amino acid and the carboxyl group of the other amino acid

According to the induced fit hypothesis of enzyme catalysis, ________. a competitive inhibitor can outcompete the substrate for the active site some enzymes change their structure when activators bind to the enzyme the binding of the substrate changes the shape of the enzyme's active site the binding of the substrate depends on the shape of the active site

the binding of the substrate changes the shape of the enzyme's active site

The complexity and variety of organic molecules is due to ________. the chemical versatility of carbon atoms the variety of rare elements in organic molecules their interaction with water their tremendously large sizes

the chemical versatility of carbon atoms

The bonding potential of an atom is determined by _______. how many protons it has in its nucleus whether or not it has extra neutrons the configuration of electrons in its outer shell All choices are correct.

the configuration of electrons in its outer shell

In DNA replication, the leading and the lagging strands differ in that ________. the leading strand is synthesized in the same direction as the movement of the replication fork, and the lagging strand is synthesized in the opposite direction the leading strand is synthesized by adding nucleotides to the 3' end of the growing strand, and the lagging strand is synthesized by adding nucleotides to the 5' end the lagging strand is synthesized continuously, whereas the leading strand is synthesized in short fragments that are ultimately stitched together the leading strand is synthesized at twice the rate of the lagging strand

the leading strand is synthesized in the same direction as the movement of the replication fork, and the lagging strand is synthesized in the opposite direction

Two plants are crossed, resulting in offspring with a 3:1 ratio for a particular trait. This ratio suggests that ________. the parents were true-breeding for contrasting traits the particular trait shows incomplete dominance each offspring has the same alleles for each of two different traits the parents were both heterozygous for the particular trait

the parents were both heterozygous for the particular trait

Cell differentiation always involves ________. the movement of cells the selective loss of certain genes from the genome the cell's sensitivity to environmental cues, such as light or heat the production of tissue-specific proteins

the production of tissue-specific proteins

There are 61 mRNA codons that specify an amino acid, but only 45 tRNAs. This is best explained by the fact that ________. some tRNAs have anticodons that recognize codons for more than one amino acid the rules for base pairing between the third base of a codon and tRNA are flexible many codons are never used, so the tRNAs that recognize them are dispensable the DNA codes for all 61 tRNAs, but some are then destroyed

the rules for base pairing between the third base of a codon and tRNA are flexible

Experiments on denaturation (unfolding) and renaturation (refolding) of proteins have shown that ____. refolding of a protein into its proper shape requires an input of energy the completely unfolded protein is still retains activity refolding of a denatured protein results in a new active shape the sequence of amino acids is sufficient to specify the proper shape of the protein

the sequence of amino acids is sufficient to specify the proper shape of the protein

Which step in gene expression is influenced by RNA interference (RNAi)? transcription initiation mRNA processing translation post-translational control

translation

When a segment of a chromosome is transferred to the end of a different chromosome, a(n) ___ has occurred. inversion deletion dulication translocation

translocation

Regulatory proteins that prevent a cell from entering the S phase under conditions of DNA damage are also known as ________. cyclins cyclin-dependent kinases tumor suppressors mitogens

tumor suppressors

The tertiary structure of a protein is the ________. bonding together of several polypeptide chains by weak bonds order in which amino acids are joined in a polypeptide chain unique three-dimensional shape of the fully folded polypeptide organization of a polypeptide chain into an α-helix or β-pleated sheet

unique three-dimensional shape of the fully folded polypeptide

Intercalated discs are cell-cell junctions between adjacent muscle cells. One feature of these discs is that they contain a large number of gap junctions, which means that ____. an extension of smooth endoplasmic reticulum goes through the gap junction, making it continuous from one muscle cell to the next water, ions, and small molecules can readily pass from one muscle cell to the next cardiac cells can function independently when necessary RNA from one cardiac muscle cell can be transported into an adjacent muscle cell

water, ions, and small molecules can readily pass from one muscle cell to the next

Forms of the Ras protein found in tumors usually cause which of the following? DNA replication to stop Cell-to-cell adhesion to be nonfunctional Cell division to cease Excessive cell division

Excessive cell division

Forms of the Ras protein found in tumors would cause which of the following? DNA replication to stop DNA replication to be hyperactive Cell division to cease Excessive cell division

Excessive cell division

A DNA molecule that has 60% A-T base pairs is more stable than the same sized DNA molecule consisting of 60% G-C base pairs. True False

F

Chromosomes move to opposite poles during anaphase because microtubules shorten at the centrosome, pulling the chromosomes which are anchored to the other end. True False

F

For a particular gene, both strands of DNA may be transcribed into mRNA. True False

F

Most proteins can tolerate a small number of amino acid sequence changes without any significant effects on its structure or function. True False

F

Signaling pathways always work in complete isolation from one another. True False

F

The arrangement of hydroxyl groups on a monosaccharide can vary, but has little effect on the function of the sugar. True False

F

The lac repressor protein is only made in the presence of lactose. True False

F

The plasma membrane of a bacteria isolated from a hot spring will have more unsaturated phospholipids that the membrane of a bacteria isolated from a frozen lake. True False

F

To create an ion, an atom must gain or lose one or more protons. True False

F

The lowest energy configuration for monosaccharides in cells is the straight chain form. True False

False

If meiosis produces haploid cells, how is the diploid number restored for those organisms that spend most of their life cycle in the diploid state? DNA replication Crossing over Fertilization Non-disjunction

Fertilization

Which cytoskeletal component helps epithelial tissue resist and distribute mechanical stress? Actin filament Intermediate filament Microtubule None of the choices is correct.

Intermediate filament

Sodium ions and chloride ions come together to form crystals of table salt. How are the atoms in these crystals held together? Ionic bonds Hydrogen bonds Non-polar covalent bonds Polar covalent bonds

Ionic bonds

Why is carbon so important in biology? It is a common element on Earth. It bonds to only a few other elements. It has very little electronegativity, making it a good electron donor. It can form a variety of carbon skeletons and have functional groups attached.

It can form a variety of carbon skeletons and have functional groups attached.

How does the enzyme telomerase meet the challenge of replicating the ends of linear chromosomes? It adds a unique 5' cap structure that resists degradation by nucleases. It causes specific double-strand DNA breaks that result in blunt ends on both strands. It causes linear ends of the newly replicated DNA to circularize. It catalyzes the addition of new repeat sequences to the 3' end of the DNA.

It catalyzes the addition of new repeat sequences to the 3' end of the DNA.

When a lipid-soluble hormone enters a cell and binds a receptor, what happens to the receptor? It synthesizes second messenger molecules. It forms a dimer and phosphorylates itself. It activates a G protein. It enters the nucleus and activates genes.

It enters the nucleus and activates genes.

Which of the following is a characteristic feature of a carrier protein in the plasma membrane? It is a peripheral membrane protein. It exhibits specificity for a particular type of molecule. It requires the expenditure of energy to function. It works against diffusion.

It exhibits specificity for a particular type of molecule.

What is the role of lactose in regulating lac operon expression? It induces transcription by binding to the repressor and removing it from the operator. It induces transcription by binding directly to the promoter. It induces translation by binding to the repressor and removing it from the mRNA. It represses transcription by binding to the repressor.

It induces transcription by binding to the repressor and removing it from the operator.

When chemical, transport, or mechanical work is done by an organism, what happens to the heat generated? It is used to power yet more cellular work. It is used to store energy as more ATP. It is lost to the environment. It is stored in special organelles.

It is lost to the environment.

What is an antenna complex? It senses the ATP/NADPH ratio in the chloroplast. It is the pair of chlorophylls that transfer electrons to an electron transport chain. It is the collection of chlorophylls and other pigments that capture light energy and transfer it to the reaction center. It is the enzyme complex that captures CO2 in the Calvin cycle.

It is the collection of chlorophylls and other pigments that capture light energy and transfer it to the reaction center.

What is an active site? It is the location on an enzyme where the substrates bind and react. It is the end of a growing polypeptide where new amino acids are being added. It is the region of a protein where in binds to another protein to form a quaternary structure. It refers to a peptide bond that is being broken in a hydrolysis reaction.

It is the location on an enzyme where the substrates bind and react.

What is a gene? It is the cellular molecule that carries hereditary information. It is the mRNA molecule copied from a segment of DNA. It is the segment of DNA that codes for a cell product. None of the choices is correct.

It is the segment of DNA that codes for a cell product.

What does it mean for a characteristic to be heritable? The characteristic evolves. The characteristic can be passed to offspring. The characteristic is advantageous to the organism. The characteristic does not vary in the population.

The characteristic can be passed to offspring.

Which choice best describes evolution? The characteristics of a species become more complex over time. The strongest individuals produce the most offspring. The characteristics of an individual change over the course of its life, in response to natural selection. The characteristics of a population change over time.

The characteristics of a population change over time.

Which bond is strongest? The covalent bond between a carbon and hydrogen atom. The covalent bond between an oxygen atom and a hydrogen atom. The hydrogen bond between two water molecules. The bond between a sodium ion and a water molecule.

The covalent bond between an oxygen atom and a hydrogen atom.

What provides the energy for the polymerization reactions in DNA synthesis? ATP DNA polymerase Breaking the hydrogen bonds between complementary DNA strands The deoxyribonucleotide triphosphate substrates

The deoxyribonucleotide triphosphate substrates

Which statement is not a component of the cell theory? The earliest cells had no nucleus. All organisms are made of cells. All cells come from pre-existing cells. All of the above are components of the cell theory.

The earliest cells had no nucleus.

What is a telomere? DNA replication during telophase. The site of origin of DNA replication. The ends of linear chromosomes. The structural distortion caused by DNA damage.

The ends of linear chromosomes.

Which of the following mechanisms is used to coordinate the expression of multiple, related genes in eukaryotic cells? Environmental signals enter the cell and bind directly to promoters. The genes share a single common enhancer, which allows appropriate activators to turn on their transcription at the same time. The genes are organized into a large operon, allowing them to be coordinately controlled as a single unit. A single repressor is able to turn off several related genes.

The genes share a single common enhancer, which allows appropriate activators to turn on their transcription at the same time.

How is the structure of saturated fats different from that of unsaturated fats? All of the carbons in the hydrocarbon tails of saturated fats are bonded to one another with double bonds. Saturated fats have three hydrocarbon tails bonded to glycerol instead of just two. Saturated fats have oxygen present, unsaturated ones do not. The hydrocarbon tails in saturated fats have the maximum number of hydrogens possible.

The hydrocarbon tails in saturated fats have the maximum number of hydrogens possible.

Working in a lab, you insert an mRNA molecule into the cytoplasm of a eukaryotic cell after you have removed its 5' cap. Which of the following would you expect to find? The mRNA is converted into a ribosomal subunit. The cell adds a new 5' cap to the mRNA. The mRNA attaches to a ribosome and is translated, but more slowly. The mRNA molecule is quickly digested by enzymes.

The mRNA molecule is quickly digested by enzymes.

You have just discovered an organism that lives in extremely cold environments. Which of the following would you predict to be TRUE about the phospholipids in its membranes, compared to phospholipids in the membranes of organisms that live in warmer environments? The membrane phospholipids of cold-adapted organisms will have longer hydrocarbon tails. The membrane phospholipids of cold-adapted organisms will have more saturated hydrocarbon tails. The membrane phospholipids of cold-adapted organisms will have more unsaturated hydrocarbon tails.

The membrane phospholipids of cold-adapted organisms will have more unsaturated hydrocarbon tails.

What is the spindle apparatus? The microtubule structure that separates chromosomes. Another name for condensed chromosomes. The part of a chromosome where microtubules attach. The structure that pinches a cell in two during cytokinesis.

The microtubule structure that separates chromosomes.

The electrons of photosystem II are excited and transferred to electron carriers. From which molecule or structure do the photosystem II replacement electrons come? The electron carrier, plastocyanin Photosystem I Water Oxygen

Water

Which pathway describes the flow of electrons in the chloroplast? Water -> photosystem II -> electron transport chain -> photosystem I -> electron transport chain -> NADPH -> glyceraldehyde-3-phosphate Water -> NADPH -> electron transport chain -> chlorophyll -> ATP CO2 -> Calvin cycle -> Glyceraldehyde-3-P -> starch Water -> photosystem I -> electron transport chain -> photosystem II -> electron transport chain -> ATP -> CO2

Water -> photosystem II -> electron transport chain -> photosystem I -> electron transport chain -> NADPH -> glyceraldehyde-3-phosphate

When does a concentration gradient exist? When membranes rupture. When solute concentrations are high. When solute concentrations are low. When solute concentrations differ on two sides of a membrane.

When solute concentrations differ on two sides of a membrane.

Under what circumstances does membrane transport require energy? Whenever large molecules are moved into the cell. Whenever a solute is moved against its electrochemical gradient. Whenever an ion moves through a phospholipid membrane. Whenever osmosis occurs.

Whenever a solute is moved against its electrochemical gradient.

Mendel crossed purple flowered plants with white flowered plants. In the F2 generation, 705 plants had purple flowers and 224 had white flowers. Which phenotype is recessive in this experiment? Purple White Neither More information is needed.

White

The structure that anchors adjacent epithelial cells via their cytoskeleton is the ____. gap junction tight junction desmosome plasmodesmata

desmosome

Vinblastine is a standard chemotherapeutic drug used to treat cancer. Because it interferes with the assembly of microtubules, its effectiveness must be related to _____. inhibition of regulatory protein phosphorylation disruption of mitotic spindle formation inhibition of DNA synthesis suppression of cyclin production

disruption of mitotic spindle formation