BIO - Mindtap Ch 20, Chapter 18.1, Chapter 19, Chapter 16, Chapter 15, Chapter 14, Chapter 13, Chapter 12, Chapter 11, Chapter 10, Chapter 9, Chapter 8, Chapter 7, Chapter 5, Chapter 4, Chapter 3, Chapter 2, Chapter 1, Chapter 6

Based on molecular analyses, scientists now believe the domestication of the closest relatives of modern dogs began between ____ years ago.

18,800 and 32,100

Gregor Mendel published his work on genetics in ____.

1866

Darwin calculated that if reproduction was not limited, a single pair of elephants would leave roughly ____ descendants after 750 years.

19 million

What percentage of the species that have ever lived have become extinct?

99 percent

A(n) _____ has a DNA sequence similar to a functional gene but has been mutated so that it no longer produces a functional gene product. a. homologous gene b. operon c. pseudogene d. orthologous gene e. microRNA-encoding sequence

A(n) _____ has a DNA sequence similar to a functional gene but has been mutated so that it no longer produces a functional gene product. a. homologous gene b. operon c. pseudogene d. orthologous gene e. microRNA-encoding sequence

Fossils and molecular techniques reveal that the closest ancient wolflike relatives of most modern dogs lived in ____.

Europe

Which statement is NOT supported by the theory of evolution?

Humans evolved from chimpanzees or gorillas.

Before Darwin, ____.

Lamarck wrote about biological evolution, but had the mechanism wrong

At first, the most important conflict between Darwin's and Mendel's theories appeared to be that ____.

Mendel's experiments were based on simple traits while Darwin's evidence was based on complex characteristics

Darwin's inference that individuals within a population compete for limited resources was based on which observation(s)?

Most organisms produce more than one or two offspring, populations do not increase in size indefinitely, and food and other resources are limited for most populations.

One reason Mendel could interpret his experimental results so clearly is because ____.

a single gene often controls simple traits

What is the probability of obtaining a head and a tail (in either order) when tossing a coin two times? a. 1/2 b. 1/4 c. 1/16 d. 1 e. 1/8

a. 1/2

We would expect to find fatty acids with ____ carbons in living organisms. a. 16 b. 19 c. 26 d. 8 e. 13

a. 16

How many hydrogen bonds are formed between adenine and thymine? a. 2 b. 3 c. 1 d. 6 e. 4

a. 2

Per molecule of glucose, oxidation occurs ____ times during the conversion of pyruvate to acetyl CoA. a. 2 b. 3 c. 4 d. 5 e. 1

a. 2

The human genome is composed of approximately _____ billion base pairs. a. 3 b. 10 c. 1 d. 14 e. 7

a. 3

The chemical difference between dideoxyribonucleotides used in Sanger sequencing and the deoxyribonucleotides normally found in DNA is the presence of a(n) _____ in the deoxyribose sugar of dideoxyribonucleotides. a. 3' - H rather than - OH b. 5' - OH rather than - H c. 5' - H rather than - OH d. 5' - H rather than - OH e. 3' - COOH rather than - OH

a. 3' - H rather than - OH

Which nucleotide sequence is complementary to the DNA sequence 5'-GACGTT-3'? a. 3'-CTGCAA-5' b. 5'-TCATGG-3' c. 3'-AGTACC-5' d. 3'-TCATGG-5' e. 5'-TTGCAG-3'

a. 3'-CTGCAA-5'

Human diploid cells have ____ chromosomes while human gametes have ____ chromosomes. a. 46; 23 b. 46; 92 c. 23; 46 d. 48; 96 e. 96; 48

a. 46; 23

How many unique chromosomes does an organism with a chromosome number of 4n=32 have? Assume that none of these are sex chromosomes, and do not count any duplicate homologous chromosomes in this number. a. 8 b. 64 c. 4 d. 16 e. 32

a. 8

Solution A has a pH of 6 and solution B has a pH of 8. Therefore, ____. a. A has 100 times greater H+ concentration than B b. B has 100 times greater H+ concentration than A c. A has 10 times greater H+ concentration than B d. A has 1,000 times greater H+ concentration than B e. B has 10 times greater H+ concentration than A

a. A has 100 times greater H+ concentration than B

Which statement correctly describes the inheritance of sex chromosomes? a. A woman will pass on an X chromosome to all of her children. b. A man will pass on an X chromosome to all of his children. c. A woman will pass on a specific X chromosome to all of her daughters. d. A woman's genetic contribution determines the sex of her children. e. A woman will pass on an X chromosome to half of her children.

a. A woman will pass on an X chromosome to all of her children.

In both prokaryotes and eukaryotes, the start codon (or initiator codon) is ____, which codes for the amino acid ____. a. AUG; methionine b. UUU; phenylalanine c. AAA; lysine d. ACG; threonine e. UGA; proline

a. AUG; methionine

A researcher obtains the results of his RNA-seq analysis. Several transcripts are listed as being derived from the same gene. How is this possible? a. Alternative splicing allows for different transcripts to be created by the same gene sequence. b. It is not possible; there was an error in the alignment process. c. Intron shuffling allows for different transcripts to be created by the same gene sequence. d. The researcher's sample was contaminated. e. Exon shuffling allows for different transcripts to be created by the same gene sequence.

a. Alternative splicing allows for different transcripts to be created by the same gene sequence.

Which molecule(s) is/are responsible for delivering the high-energy electrons from the citric acid cycle to the electron transfer system? a. Both NADH and FADH2 b. NADH only c. Cyt C and Q d. ATP and ADP e. FADH2 only

a. Both NADH and FADH2

Photosynthesis must provide a source of electrons and H+ because ____. a. CO2 must be reduced to produce sugars b. atmospheric CO2 must be oxidized by adding electrons c. hydrogen atoms are added to oxygen to form water d. hydrogen ions and electrons are converted into oxygen gas e. hydrogen ions and electrons react to produce hydrogen gas

a. CO2 must be reduced to produce sugars

Which statement characterizes cancer cells? a. Cancer cells display uncontrolled cell division. b. Cancer cells behave like normal cells. c. Cancer cells form tumors that adhere strongly to surrounding tissues. d. Tumors formed by cancer cells remain encapsulated and only grow in one location. e. Mitosis in cancer cells is strictly regulated.

a. Cancer cells display uncontrolled cell division.

The most fundamental and important molecule that distinguishes living systems from nonliving matter is ____. a. DNA b. protein c. fructose d. water e. glucose

a. DNA

At the conclusion of mitosis, each daughter cell has ____. a. DNA identical to the parent cell b. half the DNA and half the cytoplasm found in the parent cell c. DNA genetically different from the parent cell d. twice the cytoplasm and the same amount of DNA as the parent cell e. twice the amount of DNA and half the cytoplasm of the parent cell

a. DNA identical to the parent cell

When cloning DNA into bacteria, the ____. a. DNA sequence is inserted into a plasmid b. new DNA is directly introduced into the bacterial cell c. approach depends on the species of host bacteria used in the experiment d. linear DNA sequence is circularized, thus generating a plasmid e. DNA sequence is inserted into the bacterial chromosome

a. DNA sequence is inserted into a plasmid

The key elements of a PCR reaction are ____. a. DNA with the target sequence to be amplified, a pair of primers, the four nucleoside triphosphates, and DNA polymerase b. a pair of primers, the four nucleoside triphosphates, DNA primase, and DNA polymerase c. the four nucleoside triphosphates, DNA primase, DNA polymerase, and an agarose gel d. DNA with the target sequence to be amplified, a pair of primers, the four nucleoside triphosphates, and DNA primase e. DNA with the target sequence to be amplified, the four nucleoside triphosphates, DNA primase, and DNA polymerase

a. DNA with the target sequence to be amplified, a pair of primers, the four nucleoside triphosphates, and DNA polymerase

A patient with a mitochondrial disease is found to have a mutation in Gene X. A homologous gene in a Drosophila (fruit fly), did not cause a similar deficit. What does this suggest? a. Gene X is not conserved between humans and Drosophila. b. Gene X is encoded in mitochondrial DNA. c. Gene X is highly conserved between humans and Drosophila. d. Gene X is encoded in nuclear DNA. e. Gene X is a redundant protein in Drosophila.

a. Gene X is not conserved between humans and Drosophila.

Which statement describes a difference between meiosis I and meiosis II? a. Homologous chromosomes separate during meiosis I; sister chromatids separate during meiosis II. b. Meiosis I produces diploid cells; meiosis II produces haploid cells. c. Crossing-over occurs during meiosis II but not during meiosis I. d. DNA is replicated during meiosis II but not during meiosis I. e. Chromosomes align along the equatorial plane of the cell in meiosis I but not in meiosis II.

a. Homologous chromosomes separate during meiosis I; sister chromatids separate during meiosis II.

What is the key difference between incomplete dominance and codominance? a. In incomplete dominance, it is possible to detect the expression of a recessive allele; in codominance, both alleles contribute equally to the phenotype. b. In codominance, it is possible to detect the expression of a recessive allele; in incomplete dominance, both alleles contribute equally to the phenotype. c. In incomplete dominance, it is possible to detect the expression of the dominant allele; in codominance, two different genes contribute to a single phenotype. d. In incomplete dominance, the recessive allele cannot be detected; in codominance, the expression of the recessive allele is apparent. e. The two terms are synonymous.

a. In incomplete dominance, it is possible to detect the expression of a recessive allele; in codominance, both alleles contribute equally to the phenotype.

What supplies the electrons for oxidative phosphorylation? a. NADH and FADH2 b. ATP c. ATP synthase d. glucose e. the proton gradient

a. NADH and FADH2

Why does NADH produce more energy than FADH2? a. NADH has a high free energy and can be oxidized more readily than FADH2. b. FADH2 requires more ATP to produce it and gives more energy back. c. FADH2 donates electrons to protein complex III as opposed to complex II. d. NADH and FADH2 are synthesized in different steps of cellular respiration. e. NADH supplies fewer electrons that are of a higher energy state than FADH2.

a. NADH has a high free energy and can be oxidized more readily than FADH2.

Chloroplasts kept in the dark can continue to make sugar if provided with ____. a. NADPH, ATP, and CO2 b. CO2 and ATP c. NADPH, CO2, and ADP d. water and ATP e. NADPH and ATP

a. NADPH, ATP, and CO2

Which organism has the largest number of protein-coding genes? a. Oryza sativa (rice) b. Saccharomyces cerevisiae (yeast) c. Drosophila melanogaster (fruit fly) d. E. coli (bacteria) e. Homo sapiens (human)

a. Oryza sativa (rice)

Protein-encoding genes in eukaryotes are transcribed by ____. a. RNA polymerase II b. RNA polymerase III c. RNA polymerase I d. either RNA polymerase I or III e. either RNA polymerase II or III

a. RNA polymerase II

Which technique can most accurately quantify RNA and determine levels of gene expression? a. RNA-seq b. microarray analysis c. Sanger sequencing d. alignment searches e. Illumina/Solexa sequencing

a. RNA-seq

Which notation represents a dihybrid cross? a. RrMm × RrMm b. rrMM × RRmm c. RRMM × rrmm d. RrMm × rrmm e. RrMM × Rrmm

a. RrMm × RrMm

Centriole replication occurs during ____. a. S phase b. telophase c. prophase d. G1 phase e. G2 phase

a. S phase

The conversion of a diamond into graphite is a spontaneous reaction. Why are most women walking around with diamond rings and not graphite rings? a. The energy of activation is very high. b. The free energy of this reaction is too low. c. The free energy of this reaction is too high. d. Inorganic substances, like diamonds, do not react like organic substances. e. The transition state is very stable.

a. The energy of activation is very high.

When a photon of light is absorbed by a pigment molecule, electrons jump to an excited state. What is one possible fate of these excited electrons? a. The excited electrons jump to a lower energy level, releasing energy to a nearby pigment molecule. b. The excited electrons jump to a lower energy level, releasing energy in the form of ATP. c. The excited electrons are transferred to an electron donor molecule. d. The excited electrons release energy in the form of a photon. e. The excited electrons revert back to their ground state without releasing any energy.

a. The excited electrons jump to a lower energy level, releasing energy to a nearby pigment molecule.

Why are numerous replication cycles - each performed at three difference temperatures - a necessary part of a PCR reaction? a. The initial cycles do not produce many copies of the target sequence, but since the number of molecules produced doubles with each cycle, millions of copies are produced after 20-30 cycles. b. The bacteria used in the reaction divide with each cycle, replicating the target DNA. c. The initial cycles amplify DNA slowly, but as the temperature increases, DNA polymerase works more quickly to produce millions of copies of the target sequence. d. Once the enzyme starts working, it must continue until there are no remaining nucleotides. e. Only non-target DNA is made during the first 10 cycles, while only cycles 11-20 specifically target the gene of interest.

a. The initial cycles do not produce many copies of the target sequence, but since the number of molecules produced doubles with each cycle, millions of copies are produced after 20-30 cycles.

How is a DNA fragment containing a gene of interest generated for cloning? a. The polymerase chain reaction (PCR) amplifies the DNA fragment from the genome. b. The gene with a cloning vector is ligated. c. DNA fingerprinting allows the fragment to be copied from the chromosome. d. Agarose gel electrophoresis takes place. e. A DNA polymerase specific for the fragment is used to make copies.

a. The polymerase chain reaction (PCR) amplifies the DNA fragment from the genome.

Which statement is true for exergonic reactions? a. The products have less free energy than the reactants. b. The products have more free energy than the reactants. c. The reactants will always be completely converted to products. d. A net input of energy is necessary for the reaction to proceed. e. The entropy of the system is reduced.

a. The products have less free energy than the reactants.

If the inner membrane of the mitochondria were compromised in some way, what effect would this have on cellular respiration? a. The proton gradient across the inner mitochondrial membrane would dissipate. b. The cell would generate more ATP. c. The ATP synthase enzyme would relocate to the mitochondrial matrix. d. ATP would no longer be made anywhere in the cell by any mechanism. e. The transport of electrons across the inner mitochondrial membrane would not occur.

a. The proton gradient across the inner mitochondrial membrane would dissipate.

What is the fate of electrons from NADPH during the Calvin cycle? a. They are added to 3PGA. b. They are transferred to rubisco. c. They are used to regenerate RuBP from G3P. d. They are accepted by molecular oxygen, just like in cellular respiration. e. They remain on NADPH to help drive the light reactions.

a. They are added to 3PGA.

When individuals have mitochondrial disorders, why are the skeletal and heart muscles and the brain most often affected? a. They have the highest energy needs. b. They are the most important organs. c. They are generally very fragile. d. They are the most complex organs. e. They have fewer mitochondria in the cell.

a. They have the highest energy needs.

What are the functions of cytochrome c and ubiquinone? a. They shuttle electrons between the protein complexes. b. They produce ATP by substrate-level phosphorylation. c. They produce ATP by oxidative phosphorylation. d. They translocate protons from the matrix to the inner mitochondrial space. e. They synthesize water from molecular oxygen.

a. They shuttle electrons between the protein complexes.

How is lac operon transcription regulated by the presence or absence of lactose? a. When lactose is available, the repressor will bind to allolactose instead of blocking RNA polymerase. b. When lactose is not available, the repressor will bind to the promoter and block RNA polymerase from binding to the promoter. c. When lactose is not available, the repressor will bind to allolactose. d. In the absence of lactose, transcription occurs at a low level resulting in the production of allolactose, which in turn stimulates the cell to take up lactose. e. When lactose is available, allolactose is produced and binds to the operator, blocking RNA polymerase.

a. When lactose is available, the repressor will bind to allolactose instead of blocking RNA polymerase.

Examine the pedigree in the figure above. Individuals affected by the genetic condition in question are indicated by filled squares or circles. Which inheritance pattern is most likely correct for this condition in this family? a. X-linked dominant b. autosomal recessive c. cytoplasmic inheritance d. X-linked recessive e. autosomal dominant

a. X-linked dominant

Substance C is secreted from a neuron, and binds to its receptor on a nearby cell, triggering an increase in intracellular cAMP. Substance C is therefore a ligand for a ____. a. a G-protein-coupled receptor b. a hormone receptor c. a receptor tyrosine kinase d. a ligand-gated ion channel e. guanylyl cyclase

a. a G-protein-coupled receptor

Fluorescence occurs when ____. a. a high-energy electron returns to its ground state by releasing energy in a photon b. a high-energy electron leaves its nucleus and moves to a different molecule c. the energy from an electron is transferred to a different molecule while the electron returns to the ground state d. a low-energy electron moves to a high-energy state by absorbing heat e. a pigment molecule accepts a high-energy electron and releases a photon of energy

a. a high-energy electron returns to its ground state by releasing energy in a photon

The substance O2 is considered to be ____. a. a molecule but not a compound b. both a molecule and an ion c. both a molecule and a compound d. neither a molecule nor a compound e. a compound but not a molecule

a. a molecule but not a compound

Substance E is made in the pancreas, travels through the blood, and binds to a surface receptor on a target cell. After dimerization and autophosphorylation, the receptor activates a signaling protein. Substance E is therefore the ligand for ____. a. a receptor tyrosine kinase b. a ligand-gated ion channel c. guanylyl cyclase d. a G-protein-coupled receptor e. a hormone receptor

a. a receptor tyrosine kinase

The two amino acids depicted above both have side groups (R groups) that are ____. a. acidic and polar b. acidic and nonpolar c. uncharged and nonpolar d. uncharged and polar e. basic and polar http://cnow.apps.ng.cengage.com/ilrn/books/ru2bd04t/MTQA-83611_Images/ch03_image14.JPEG

a. acidic and polar

Inactive Ras is bound to receptor tyrosine kinases by ____. a. adapter proteins b. phosphate bonds c. GDP d. peptide tethers e. G proteins

a. adapter proteins

Protein kinases ____. a. add phosphate groups to proteins b. hydrolyze proteins c. polymerize amino acids d. bind cGMP e. stimulate adenylyl cyclase

a. add phosphate groups to proteins

In humans, telomerase ____. a. adds telomere repeats in some human cells b. adds telomere repeats in all human cells c. removes telomere repeats in some human cells d. transcribes telomere repeats in some human cells e. removes telomere repeats in all human cells

a. adds telomere repeats in some human cells

In the cAMP pathway, the G protein activates ____. a. adenylyl cyclase b. diacylglycerol c. phospholipase C d. inositol triphosphate e. phosphodiesterase

a. adenylyl cyclase

Variations in pre-mRNA processing, such as in ____, can determine which ____ are made in cells. a. alternative splicing; proteins b. genomic imprinting; transcripts c. histone modifications; transcripts d. alternative splicing; transcripts e. exon shuffling; proteins

a. alternative splicing; proteins

Duplicated centrioles move to opposite poles of ____ cell during ____ of the cell cycle. a. an animal; prophase b. an animal; metaphase c. a plant; metaphase d. a plant; prophase e. both animal and plant cells; prophase

a. an animal; prophase

Which characteristic of the light-absorbing regions of chlorophylls and carotenoids most likely accounts for the ability of these molecules to absorb light? a. an extensive network of double bonds b. the presence of magnesium c. the presence of aldehyde side-groups d. ringed structures e. long hydrocarbon chain

a. an extensive network of double bonds

Steroid and thyroid hormones do not bind to membrane surface receptors because they ____. a. are soluble in the lipid bilayer b. dissolve in the cholesterol present in cell membranes c. are water-soluble d. are small enough to pass directly through the membrane e. pass through special membrane channels

a. are soluble in the lipid bilayer

Bacteria and protozoans ____. a. are unicellular organisms b. reside solely in oceans c. are precursors to cells d. are multicellular organisms e. can be either unicellular or multicellular organisms

a. are unicellular organisms

Some transcriptional repressors work by ____. a. binding to the same sequence where activators normally bind b. recruiting histone acetylation enzymes and thus interfering with chromatin remodeling c. binding to RNA polymerase II and preventing it from binding to the transcription factor complex d. binding to and disabling the activator e. methylating DNA

a. binding to the same sequence where activators normally bind

The observations you make and experimental data you collect in your biology laboratory class are examples of ____. a. biological research b. model systems c. statistical analysis d. biological dogma e. hypothesis building

a. biological research

The science of ____ explains the origin and persistence of life, and studies the changes in living things. a. biology b. pharmacology c. chemistry d. mathematics e. nanotechnology

a. biology

Carrier molecules are utilized for ____. a. both active and passive transport b. active transport only c. passive transport only d. osmosis e. transport of all types of molecules

a. both active and passive transport

Scientists believe that mitochondria may have evolved from ancient bacteria because ____. a. both have their own DNA and ribosomes b. both have five chromosomes c. both have cristae to increase surface area d. the shapes and size of both are exactly the same e. both are surrounded by a cell wall

a. both have their own DNA and ribosomes

Which type of microscopy passes light directly through a stained and killed specimen? a. bright field microscopy b. phase-contrast microscopy c. confocal laser scanning microscopy d. scanning electron microscopy e. fluorescence microscopy

a. bright field microscopy

Crossing-over ____. a. can occur at multiple sites in each set of paired chromosomes b. can only occur once for each non-sister chromatid c. can only occur once for each homologous chromosome pair d. only takes place towards the middle of chromatids e. only takes place between sister chromatids

a. can occur at multiple sites in each set of paired chromosomes

What is the correct order of the three phases of the Calvin cycle? a. carbon fixation, reduction, regeneration b. oxidation, carbon fixation, regeneration c. carbon fixation, regeneration, oxidation d. carbon fixation, oxidation, regeneration e. carbon fixation, regeneration, reduction

a. carbon fixation, reduction, regeneration

Where is the centromere found? a. central region of a chromosome where the spindle microtubules attach b. center of the cell where the nucleus is found during prophase c. position where metaphase chromosomes align d. location where chromosomes cluster during telophase e. location where the mitotic spindle forms

a. central region of a chromosome where the spindle microtubules attach

Eukaryotic cilia and flagella arise from which of the following cellular components? a. centrioles b. nucleus c. Golgi complex d. nucleolus e. chromosomes

a. centrioles

When histones are rearranged to control gene access, it is called ____. a. chromatin remodeling b. acetylation c. remodeling complex formation d. transcription e. DNA condensation

a. chromatin remodeling

In prokaryotes, the DNA molecule that makes up a chromosome is ____ and has ____ replication origin. a. circular; one b. linear; one c. circular; more than one d. linear; no e. linear; more than one

a. circular; one

The first observed cells were from ____. a. cork b. pollen c. a maple leaf d. bacteria e. human skin

a. cork

Communication and integration of responses between simultaneously occurring cell signaling pathways is called ____. a. cross-talk b. amplification c. mutualistic responding d. signal transduction e. effector coordination

a. cross-talk

Alleles are ____. a. different versions of the same gene b. crossover sites c. sex chromosomes d. attachment sites for microtubules e. somatic cells

a. different versions of the same gene

During DNA replication, nucleosomes must ____ ahead of the replication fork and ____ after DNA is replicated. a. disassemble; reassemble b. unwind DNA; disassociate c. cut DNA; ligate DNA d. synthesize primers; proofread e. reassemble; disassemble

a. disassemble; reassemble

In an mRNA transcript, the 3' UTR refers to the region of the mRNA that is ____. a. downstream from the stop codon b. the coding region c. upstream from the start codon d. downstream from the site for termination of transcription e. upstream from the site for initiation of transcription

a. downstream from the stop codon

The change in the chromosome depicted between the top and the bottom in the accompanying figure represents a(n) ____. (Copying gene figure) a. duplication b. deletion c. Philadelphia chromosome d. inversion e. reciprocal translocation

a. duplication

An isotonic solution has a solute concentration ____ the solute concentration inside the cell. a. equal to b. that alters c. less than d. that depends on e. greater than

a. equal to

Cells actively secreting enzymes would likely carry out more ____ than other cells. a. exocytosis b. osmosis c. conjugation d. fractionation e. endocytosis

a. exocytosis

When cells differentiate, they ____. a. express a specific subset of genes b. stop growing c. gain DNA d. lose DNA e. remain totipotent

a. express a specific subset of genes

Diluted acetic acid, CH3COOH, is commonly called vinegar. How many atoms of hydrogen are present in one molecule of acetic acid? a. four b. five c. three d. two e. one

a. four

Suppose a DNA replication error is not corrected. After two cell divisions, how many of the four daughter cells contain this mutation (assuming that the mistake was never corrected)? a. four b. two c. none d. three e. one

a. four

Egg and sperm cells are ____. a. gametes b. somatic cells c. diploid d. gametophytes e. sporophytes

a. gametes

The process by which information in genes guides the production of RNA and proteins is called ____. a. gene expression b. transcription c. synthesis d. cellular respiration e. translation

a. gene expression

Which answer best describes energy flow in biological systems? a. glucose→G3P→NADH→ATP b. G3P→glucose→ATP→NAD+ c. bacteria→archaea→plants→animals d. pyruvate oxidation→glycolysis→fermentation→citric acid cycle e. NAD+→NADH→ADP→ATP

a. glucose→G3P→NADH→ATP

The slime layer external to the prokaryotic cell wall is called the ____. a. glycocalyx b. extracellular matrix c. plasma membrane d. flagellum e. pilus

a. glycocalyx

In higher plants, thylakoids are arranged into stacks called ____. a. grana b. stromal lamellae c. stroma d. stomata e. photosystems

a. grana

Sister chromatids ______. a. have identical DNA sequences b. are replicated before meiosis I and II c. are replicated before meiosis II d. have different alleles for the same genes e. are separated during anaphase

a. have identical DNA sequences

An F1 individual resulting from a cross between a homozygous dominant parent and a homozygous recessive parent is always ____. a. heterozygous b. heterozygous or homozygous dominant c. homozygous recessive d. heterozygous or homozygous recessive e. homozygous dominant

a. heterozygous

A DNA double helix has two strands that are held together by ____. a. hydrogen bonds b. hydrophobic interactions c. ionic bonds d. covalent bonds e. phosphodiester bonds

a. hydrogen bonds

A red blood cell placed in a beaker of solution immediately begins to swell and ultimately bursts. This occurs because the cytoplasm of the cell was ____ to the solution in the beaker, which was ____. a. hypertonic; hypotonic b. hypotonic; isotonic c. hypertonic; isotonic d. isotonic; hypotonic e. hypotonic; hypertonic

a. hypertonic; hypotonic

Distilled water is ____ to body cells. a. hypotonic b. hypertonic c. aquatonic d. protonic e. isotonic

a. hypotonic

A(n) ____ environment is ideal for plant cells, while a(n) ____ environment is best for animal cells. a. hypotonic; isotonic b. hypertonic; isotonic c. isotonic; hypotonic d. isotonic; isotonic e. hypotonic; hypertonic

a. hypotonic; isotonic

Structural isomers differ from each other ____. a. in the arrangement of their covalent bonds b. by having double covalent bonds instead of single bonds c. by being mirror images that cannot be superimposed on each other d. by having different atomic isotopes in their molecules e. in their molecular formulas

a. in the arrangement of their covalent bonds

Steroid hormones ____. a. include testosterone, estrogens, and cortisol b. never alter membrane transport of ions c. are proteins d. never activate second messengers e. are large nonpolar molecules

a. include testosterone, estrogens, and cortisol

An enhancer is a sequence that increases transcription of a gene ____. a. independently of its position, orientation, and distance from a promoter b. when it is located just upstream of the promoter c. when its orientation is the same as that of the gene it controls d. when it is located just downstream of the promoter e. when it is distant from the gene it controls

a. independently of its position, orientation, and distance from a promoter

The role of a tumor suppressor protein in a cell is to ____. a. inhibit cell growth and division b. serve as a cell receptor for growth factors c. trigger DNA replication in preparation for cell division d. promote cell division of abnormal cells e. promote cell division of healthy cells

a. inhibit cell growth and division

Nitric oxide (NO) binds to an ____. a. internal receptor and activates a second messenger cascade b. external receptor and activates a second messenger cascade c. external receptor and opens a ligand-gated ion channel d. external receptor and triggers a phosphorylation cascade e. internal receptor and triggers a phosphorylation cascade

a. internal receptor and activates a second messenger cascade

The change in the chromosome depicted between the top and the bottom in the accompanying figure represents a(n) ____. (switching gene figure) a. inversion b. reciprocal translocation c. Philadelphia chromosome d. duplication e. deletion

a. inversion

When a DNA promoter sequence is methylated, ____. a. it is temporarily silenced because the methyl group can be removed b. the impact on expression depends on the gene being controlled by the promoter c. it is perpetually transcribed because the methyl group can never be removed d. it is permanently silenced because the methyl group can never be removed e. it is temporarily transcribed because the methyl group can be removed

a. it is temporarily silenced because the methyl group can be removed

Agarose gel electrophoresis separates DNA molecules according to their ____. a. length b. percentage of GC base pairs c. structure d. charge e. sequence

a. length

Acetylcholine, a neurotransmitter, binds to ____. a. ligand-gated ion channels b. MAPK c. adenylyl cyclase d. G-coupled protein receptors e. receptor tyrosine kinases

a. ligand-gated ion channels

In eukaryotes, the DNA molecule that comprises a chromosome is ____ and has ____ replication origin. a. linear, more than one b. circular, more than one c. circular, one d. linear, no e. linear, one

a. linear, more than one

Suppose that in studies of genes on the same chromosome you find the following recombination frequencies: Figure 13.1 In this case, it would be proper to say that a, c, and b are ____. a. linked genes b. different alleles of the same gene c. a trisomy resulting from nondisjunction d. three inverted genes e. linked genes that are not physically possible since the recombination frequencies do not add up

a. linked genes

The oxidation of which macromolecule yields the most energy by weight? a. lipids b. starch c. protein d. glucose e. glycogen

a. lipids

Membrane sterols, such as cholesterol, function in animal cell membranes to ____. a. maintain membrane fluidity b. increase the rate of diffusion c. receive chemical signals d. store cellular energy e. facilitate ion transport

a. maintain membrane fluidity

In animal cells, ____ radiating from the cell center anchor organelles such as the ER and Golgi complex, and provide tracks for vesicle movement. a. microtubules b. laminins c. cytokeratins d. actins e. microfilaments

a. microtubules

Oncogenes are often ____. a. mutant forms of cell cycle genes b. required for normal contact inhibition of cells c. not involved in cell division d. normal forms of cell cycle genes e. needed for normal cells to metastasize

a. mutant forms of cell cycle genes

In the mid-nineteenth century Charles Darwin and Alfred Russel Wallace observed many organisms. Based on these observations, they arrived at an explanation, called ____, for how populations change through time. a. natural selection b. evolution c. natural evolution d. creationism e. genetics

a. natural selection

Isotopes of the same element differ from each other in the number of ____. a. neutrons only b. protons and neutrons c. protons, neutrons, and electrons d. electrons only e. electrons and protons

a. neutrons only

Four elements, including ____, make up more than 96% of the mass of most living organisms. a. nitrogen b. sodium c. calcium d. potassium e. phosphorus

a. nitrogen

Which molecules are the most important for a cell to protect from damage if the cell is to stay alive and reproduce? a. nucleic acids b. amino acids c. carbohydrates d. proteins e. lipids

a. nucleic acids

In cells of human individuals with three or more X chromosomes, ____. a. one X chromosome remains active and the others are inactivated b. two X chromosomes remain active and the others are inactivated c. only one X chromosome is inactivated d. two X chromosomes remain active in females and one remains active in males; the rest are inactivated e. all of the X chromosomes remain active

a. one X chromosome remains active and the others are inactivated

Nondisjunction during meiosis I results in ____. a. one pole of the cell receiving neither member of a homologous pair of chromosomes b. a change in the status of a daughter cell from haploid to diploid c. the generation of an extra daughter cell d. a change in the status of a daughter cell from diploid to haploid e. a gamete that cannot fuse with another gamete

a. one pole of the cell receiving neither member of a homologous pair of chromosomes

Which feature of a plasmid cloning vector is necessary for the plasmid to be replicated inside a host cell? a. origin of replication b. lacZ+ gene c. ampicillin resistance gene d. restriction site e. ribosomal binding site

a. origin of replication

In the C4 pathway, which molecule is formed after the addition of CO2 to PEP? a. oxaloacetate b. 3PGA c. phosphoenolpyruvate d. pyruvate e. malate

a. oxaloacetate

The reading frame for translation is established by ____. a. pairing of initiator tRNA with the start codon b. the poly(A) tail c. removal of the cap from mRNA d. the ribosome binding site e. the first base in the mRNA molecule

a. pairing of initiator tRNA with the start codon

The breakdown of hydrogen peroxide, a toxic substance, occurs in small, specialized membrane-bound organelles called ____. a. peroxisomes b. glyoxysomes c. lysosomes d. cisternae e. glycosomes

a. peroxisomes

The study of gene function by observing changes in phenotype is termed _____. a. phenomics b. proteomics c. mutagenomics d. transcriptomics e. genomics

a. phenomics

The effects of protein kinases are reversed by another group of enzymes called ____. a. phosphatases b. hydrolases c. proteases d. isomerases e. catalases

a. phosphatases

The synthesis of ATP coupled to the transfer of electrons energized by photons of light is called ____. a. photophosphorylation b. phosphorylative oxidation c. photorespiration d. photosynthesis e. oxidative phosphorylation

a. photophosphorylation

Cell walls are found in ____. a. plant and fungal cells b. plant cells only c. fungal cells only d. animal and plant cells e. animal cells only

a. plant and fungal cells

Humans with mutations in the AQP1 (aquaporin-1) gene do not produce the AQP1 protein. The absence of AQP1 causes an inability to ____ in these individuals. a. produce concentrated urine b. salivate c. recognize thirst d. control sweating e. make large volumes of dilute urine

a. produce concentrated urine

Allosteric inhibitors are often ____. a. products of the reactions that they regulate b. competitive inhibitors c. charged amino acids in the active site d. substrates of the reactions they regulate e. large, complex organic molecules

a. products of the reactions that they regulate

During the mitotic spindle checkpoint, ____. a. proper spindle attachment to chromosomes is assessed b. cells are in anaphase c. cells enter G0 d. cells become irreversibly committed to S phase e. cells arrest if chromosomes are attached properly to the mitotic spindle

a. proper spindle attachment to chromosomes is assessed

Chromatin condenses into chromosomes and the mitotic spindle begins to form during ____. a. prophase b. metaphase c. telophase d. anaphase e. interphase

a. prophase

The poly(A) tail of an mRNA ____. a. protects the mRNA from attack by RNA-digesting enzymes b. covers the stop codon until it is needed c. is where the start codon is located d. is where translation terminates e. is where ribosomes attach at the start of translation

a. protects the mRNA from attack by RNA-digesting enzymes

Initiation factors are ____ that assist in the initiation of transcription. a. proteins b. snRNPs c. amino acids d. tRNAs e. mRNAs

a. proteins

The primary purpose of the light-dependent reactions is to ____. a. provide electrons and energy for the light-independent reactions b. transfer electrons to the primary electron acceptors c. produce sugars such as glucose d. generate O2 gas e. make ADP in cyclic photophosphorylation

a. provide electrons and energy for the light-independent reactions

Characters that have a continuous distribution, such as height, weight, and skin color, are called ____, and the individual genes that control them are known as ____. a. quantitative traits; quantitative trait loci b. quantitative markers; quantitative trait markers c. quantitative genotypes; quantitative trait loci d. quantitative traits; quantitative trait markers e. quantitative phenotypes; quantitative trait markers

a. quantitative traits; quantitative trait loci

What happens immediately after a signaling molecule binds to an RTK? a. receptor dimerization b. receptor trimerization c. receptor polymerization d. receptor hydrolysis e. receptor denaturation

a. receptor dimerization

In normal cells, cell adhesion molecules are partially responsible for the cell's ability to ____. a. recognize other cells as "self" b. recognize linkages between cells in muscle and bone c. both migrate to new locations in the body and recognize other cells as "self" d. migrate to new locations in the body e. exocytosis

a. recognize other cells as "self"

Which of these waves has the longest wavelength? a. red visible light b. blue visible light c. gamma rays d. x-rays e. UV rays

a. red visible light

Proteomics _____. a. refers to the analysis of the entire protein content of a cell b. uses DNA chips c. studies mRNA levels d. refers to the analysis of all the DNA of a species e. looks only at plasmids

a. refers to the analysis of the entire protein content of a cell

The trp operon is an example of a(n) ____ operon where tryptophan acts as a(n) ____. a. repressible; corepressor b. inducible; inducer c. inducible; activator d. repressible; inducer e. repressible; repressor

a. repressible; corepressor

Noller's research with ribosomes showed that the site of peptide bond formation is located on ____. a. ribosomal RNA b. proteins of the large ribosomal subunit c. the tRNA molecules d. ribosomal DNA e. proteins of the small ribosomal subunit

a. ribosomal RNA

Every protein is assembled on a(n) ____ according to instructions copied from ____, using ____ as an intermediate. a. ribosome; DNA; mRNA b. ribosome; mRNA; tRNA c. tRNA; mRNA; DNA d. mRNA; tRNA; DNA e. tRNA; DNA; mRNA

a. ribosome; DNA; mRNA

Activated G proteins ____. a. separate into two parts b. activate a kinase c. bind to second messengers d. inhibit guanylyl cyclase e. trigger endocytosis of the G-protein-coupled receptor

a. separate into two parts

Reiji Okazaki discovered what are now called "Okazaki fragments" produced during DNA replication. These fragments are ____. a. short lengths of new DNA on the lagging strand b. short lengths of new DNA on the leading strand c. RNA primers on the lagging strand d. RNA primers on the leading strand e. RNA primers on both the lagging and leading strand

a. short lengths of new DNA on the lagging strand

In general, a cell receiving a message undergoes three stages of cell signaling. What are these stages? a. signal reception, signal transduction, and cellular response b. paracrine, autocrine, and local c. signal reception, cellular response, and cell division d. the alpha, beta, and gamma e. signal reception, nucleus disintegration, and apoptosis

a. signal reception, signal transduction, and cellular response

Nonpolar signaling molecules enter the cell by ____. a. simple diffusion b. osmosis c. active transport d. receptor-mediated endocytosis e. facilitated diffusion

a. simple diffusion

A trace element is one found in specific organisms in ____ quantities and is ____ for normal biological functions. a. small; vital b. small; unnecessary c. moderate; vital d. large; unnecessary e. moderate; unnecessary

a. small; vital

When sugar dissolves in water, water is acting as a ____ and the sugar molecules are acting as ____. a. solvent; solutes b. solute; solvents c. solute; solutions d. solution; solvents e. solvent; solutions

a. solvent; solutes

The process of removing introns from mRNA and joining exons together occurs in a complex called the ____. a. spliceosome b. lariat c. anticodon d. polysome e. ribosome

a. spliceosome

Enzymes aid in metabolism by ____. a. stabilizing the transition state b. changing the Δ G of the reaction c. adding additional reactants to the system d. removing unused reactants from the system e. slowing the rate of some reactions and increasing the rate of other reactions

a. stabilizing the transition state

When water molecules exposed to the air form hydrogen bonds between adjacent water molecules below and beside them, molecules in the upper layer become more resistant to separating from those underneath. This property of water is known as ____. a. surface tension b. a water lattice c. cohesion d. a hydration layer e. adhesion

a. surface tension

When two pairs of homologous chromosomes join for crossing-over, the complex is called a ____. a. tetrad b. kinetochore c. chiasmata d. sister chromatid e. centromere

a. tetrad

Pre-mRNA is modified on its 5' end by ____. a. the addition of a guanine cap b. aminoacylation c. exon shuffling d. the addition of a poly(A) tail e. mRNA splicing

a. the addition of a guanine cap

Mutations are ____. a. the basis of variability among individuals b. always bad for populations c. always good for populations d. always harmful for individuals e. the basis of homogeneity in a population

a. the basis of variability among individuals

Posttranslational modification includes ____. a. the chemical modification, processing, and degradation of proteins b. the binding of miRNAs to mRNA c. chromatin remodeling d. cleavage of poly-A tails from mRNA e. splicing of mRNAs

a. the chemical modification, processing, and degradation of proteins

The selective permeability of a cell membrane is due to ____. a. the hydrophobic core formed by the phospholipid tails b. the hydrophilic surface facing the cell's exterior c. the position of cholesterol in the membrane bilayer d. the hydrophilic core formed by the phospholipid tails e. glycolipids on the surface of the membrane

a. the hydrophobic core formed by the phospholipid tails

Isomers are two or more molecules with ____ chemical formula and ____ molecular structures. a. the same; different b. a different; different c. a different; the same d. a structural; theoretical e. the same; the same

a. the same; different

The molecule in the accompanying figure is glyceraldehyde, an example of a ____ sugar. a. triose b. pentose c. hexose d. tetrose e. heptose

a. triose

In prokaryotes, the genes for metabolic pathways are ____. a. turned on and off as conditions change b. always expressed so the bacteria can respond to rapidly to changing conditions c. generally expressed at low levels, but expressed at high levels when conditions warrant d. always expressed for early steps in the pathway, but generally not expressed for later steps in the pathway e. always independently regulated

a. turned on and off as conditions change

During autophosphorylation, RTKs add phosphate groups to which amino acids? a. tyrosine b. threonine c. tryptophan d. serine e. glycine

a. tyrosine

Helicase ____. a. unwinds the double-stranded DNA helix b. proofreads the newly synthesized DNA c. binds DNA polymerase to the template strand d. rewinds the newly synthesized DNA strands into a double-stranded helix e. relieves overtwisting ahead of the DNA replication fork

a. unwinds the double-stranded DNA helix

Geckos are able to cling to vertical walls due to ____. a. van der Waals forces b. hydrogen bonds c. nonpolar covalent bonds d. ionic bonds e. polar covalent bonds

a. van der Waals forces

Which reaction is most likely to have more products than reactants when it reaches equilibrium? a. Δ G = - 100 kcal/mol b. They will all have the same ratio of products to reactants regardless of the Δ G value. c. Δ G = - 50 kcal/mol d. Δ G = - 75 kcal/mol e. Δ G = - 25 kcal/mol

a. Δ G = - 100 kcal/mol

Which equation is used to calculate the free energy associated with a reaction? a. ΔG = ΔH-TΔS b. ΔG = ΔH+TΔS c. ΔG = -ΔS-TΔH d. ΔG = - ΔH+TΔS e. ΔG = ΔS+TΔH

a. ΔG = ΔH-TΔS

Amylose is a polymer made up of glucose monomers joined by ____. a. α (1-4) linkages b. α (1-6) linkages c. β (1-4) linkages d. both β (1-4) and α (1-6) linkages e. β (1-6) linkages

a. α (1-4) linkages

Genetically based characteristics that make organisms more likely to survive and reproduce are referred to as ____.

adaptive traits

Today, all biological research is undertaken with the recognition that ____.

all living organisms share the same common ancestor

As a young child, you preferred to collect shells and insects, dig through the mud around a pond, and watch birds rather than play video games. What did you have in common with Charles Darwin?

an interest in natural history

A human egg is approximately 100 μ m, or ____ mm, in diameter. a. 0.0010 b. 0.10 c. 1.0 d. 10.0 e. 0.010

b. 0.10

If your mother is heterozygous for Huntington's disease, which is caused by a dominant allele, the odds that you will inherit the disorder from her are ____. a. 1/4 b. 1/2 c. 1 d. 3/4 e. 0

b. 1/2

The percentage of the human genome that is protein-coding is less than _____. a. 50% b. 2% c. 20% d. 85% e. 30%

b. 2%

If a restriction endonuclease cuts a circular DNA three times, how many fragments should there be after the DNA is subjected to electrophoresis through an agarose gel? a. 4 b. 3 c. 1 d. 5 e. 2

b. 3

Identify the correct steps for cloning a gene of interest, then arrange them in the correct order. 1. Transform the bacteria. 2. Incubate the DNA fragments and cut cloning vector with DNA ligase. 3. Use restriction enzymes to cut the gene of interest and the cloning vector. 4. Spread bacteria on medium containing lactose and ampicillin. 5. Spread bacteria on medium containing X-gal and ampicillin. a. 4, 3, 1, 5 b. 3, 2, 1, 5 c. 2, 3, 1, 5 d. 3, 2, 1, 4 e. 3, 2, 5, 1

b. 3, 2, 1, 5

If a restriction endonuclease cuts a linear DNA three times, how many fragments should there be after the DNA is subjected to electrophoresis through an agarose gel? a. 1 b. 4 c. 3 d. 5 e. 2

b. 4

At the conclusion of S phase, a diploid cell with 40 chromosomes will have ____ chromosomes and _____ sister chromatids. a. 20; 40 b. 40; 80 c. 40; 40 d. 20; 20 e. 80; 80

b. 40; 80

If you were to extract all of the proteins from a leaf and measure the composition of rubisco, you would find that it comprises about ____% of the total leaf protein. a. 25 b. 50 c. 90 d. 10 e. 75

b. 50

What is the optimum pH of most enzymes? a. 3 b. 7 c. 9 d. 5 e. 1

b. 7

In which situation would gene cloning occur? a. A DNA fragment is inserted into a plasmid, which is then introduced into a bacterium where the gene is expressed but the plasmid does not replicate. b. A DNA fragment is inserted into a plasmid, which is then introduced to a bacterium where the plasmid replicates. c. A DNA fragment is inserted directly into a bacterium and is replicated. d. A protein of interest is taken up by a bacterium, which incorporates the protein into its cell membrane. e. A DNA fragment is inserted directly into a bacterium and is digested by nucleases.

b. A DNA fragment is inserted into a plasmid, which is then introduced to a bacterium where the plasmid replicates.

Translation ends when a stop codon in the ____ site allows a ____ to bind there. a. P; release factor b. A; release factor c. E; terminator tRNA d. A; terminator tRNA e. P; terminator tRNA

b. A; release factor

The map distances for four linked genes are as follows: A is 22 cM from B, B is 7 cM from C, C is 9 cM from D, B is 2 cM from D, A is 20 cM from D, and A is 29 cM from C. Based on these data, what is the order of these four genes on the chromosome? a. ABCD b. ADBC c. ABDC d. BADC e. CADB

b. ADBC

In secondary active transport, when the driving ion concentration is high and the transport ion concentration is low outside of the cell, in which direction will the two ions move? a. As the driving ion moves in, the transport ion moves out. b. As the driving ion moves in, the transport ion moves in. c. As the driving ion moves out, the transport ion moves in. d. As long as both ions are moving together, they can go either in or out. e. As the driving ion moves out, the transport ion moves out.

b. As the driving ion moves in, the transport ion moves in.

In secondary active transport, when both the driving ion and the transport ion are in high concentration outside of the cell, in which direction will the two ions move? a. As long as both ions are moving together, they can go either in or out. b. As the driving ion moves in, the transport ion moves out. c. As the driving ion moves out, the transport ion moves in. d. As the driving ion moves in, the transport ion moves in. e. As the driving ion moves out, the transport ion moves out.

b. As the driving ion moves in, the transport ion moves out.

Most cancers require at least two mutations: 1) one in an oncogene, which encodes proteins that trigger cell division, and 2) one in a tumor suppressor gene, whose protein products, in their unmutated form, play a key role in preventing the cell cycle from progressing if the DNA is damaged or in the absence of specific cues. Which class of proteins might be considered tumor suppressors? a. cyclins b. Cdk inhibitors c. microtubules d. transcription factors e. growth factor receptors

b. Cdk inhibitors

Koopman's research on mouse meiosis revealed ____. a. a meiosis-inhibiting gene promotes retinoic acid production b. Cyp26b1 gene expression in embryonic testes but not ovaries c. germ cells form later in male mice that lack the Cyp25b1 gene d. a meiosis-promoting gene e. that retinoic acid prevents meiosis

b. Cyp26b1 gene expression in embryonic testes but not ovaries

In whole-genome shotgun sequencing, ____. a. DNA is broken into individual nucleotides that are sequenced and then assembled using computer algorithms b. DNA is broken into many random, overlapping fragments that are sequenced and then assembled using computer algorithms c. whole chromosomes are sequencedintact from the 3'end to the 5' end d. DNA is broken into a few, non-overlapping fragments that can be read directly by computer algorithms e. whole chromosomes are sequenced intactfrom the 5'end to the 3' end

b. DNA is broken into many random, overlapping fragments that are sequenced and then assembled using computer algorithms

After DNA repair enzymes remove an incorrect nucleotide resulting from a replication error, ____ is/are needed to complete the repair. a. primase and DNA ligase b. DNA polymerase and DNA ligase c. DNA polymerase d. primase and DNA polymerase e. primase, DNA polymerase, and DNA ligase

b. DNA polymerase and DNA ligase

Although energy cannot be created or destroyed, energy transformations are not 100% efficient. Why? a. Energy is lost as an increase in heat. b. Energy is lost as an increase in entropy. c. Energy is lost as a decrease in entropy. d. Energy is lost as a decrease in heat. e. Energy is lost as a change in free energy.

b. Energy is lost as an increase in entropy.

After a long period of gradual evolution of protein domains, a period of explosive change (the "big bang") in protein domain complexity occurred at roughly the same time as the 3 taxonomic domains were undergoing rapid diversification. In which taxonomic domain was this diversification most extensive? a. Protista b. Eukarya c. Archaea d. Animalia e. Bacteria

b. Eukarya

Shitake mushrooms are decomposers that break down biological molecules from dead organisms. These organisms belong to the ____ kingdom. a. Bacteria b. Fungi c. Plantae d. Animalia e. Protist

b. Fungi

Generally, which phase of the cell cycle varies the most in length? a. All phases are the same length among cells b. G1 c. G2 d. S e. M

b. G1

A cell is committed to progressing through the cell cycle through to mitosis once it transitions from ____. a. G2 to prophase b. G1 to S c. S to G2 d. telophase to cytokinesis e. G1 to G0

b. G1 to S

G proteins are inactivated when ____. a. the G protein rebinds the receptor b. GTP is converted to GDP c. the G protein is released from the receptor d. the receptor is broken down e. GDP is converted to GTP

b. GTP is converted to GDP

Rubisco has 16 subunits joined together to make a functional unit. Eight of the subunits are large, the other 8 are small. What does this tell you about this protein's structure? a. The primary sequence of all 16 subunits is identical, which is a unique property of enzymes participating in photosynthesis. b. It is an example of quaternary protein structure. c. The subunits each have 8 alpha helices to which CO2 and RuBP bind. d. The protein has tertiary structure plus secondary structure domains, but no quaternary structure. e. It's an enzyme that is extremely resistant to denaturation.

b. It is an example of quaternary protein structure.

As a result of fermentation, cells produce ____. a. FAD b. NAD+ c. O2 d. NADH e. ADP

b. NAD+

How are purines distinguished from pyrimidines? a. Purines are found only in DNA, while pyrimidines are found only in RNA. b. Purines are derived from a pair of fused C-N rings, while pyrimidines are derived from a single C-N ring. c. Pyrimidines are derived from a pair of fused C-N rings, while purines are derived from a single C-N ring. d. Purines have a carbon-containing ring, while pyrimidines have a nitrogenous ring. e. Pyrimidines have a carbon-containing ring, while purines have a nitrogenous ring.

b. Purines are derived from a pair of fused C-N rings, while pyrimidines are derived from a single C-N ring.

What enables a PCR-amplified gene to be inserted into a cloning vector? a. The PCR-amplified gene is cut with one restriction enzyme, then ligated to a cloning vector cut by a different restriction enzyme. b. Restriction enzyme sites are added to the 5¢ ends of both primers; therefore, digestion of the PCR-amplified gene allows ligation to a cloning vector cut with the same restriction enzyme. c. The cloning vector is added to the PCR reaction, and once the gene is amplified, it immediately ligates to the cloning vector. d. The PCR-amplified gene is sequenced to locate restriction sites in order to determine which restriction enzymes to use for cloning. e. The PCR reaction adds sticky ends onto the amplified DNA, allowing ligation to a cloning vector.

b. Restriction enzyme sites are added to the 5' ends of both primers; therefore, digestion of the PCR-amplified gene allows ligation to a cloning vector cut with the same restriction enzyme.

Zhang and Cech's experiments confirmed which feature of ribozyme activity? a. Ribozymes inhibit rates of biological reactions. b. Ribozymes catalyze formation of bonds between amino acids in protein synthesis. c. Ribozymes provide a possible solution to the question of whether proteins or nucleic acids appeared first in evolution. d. Ribozymes can link nucleic acids together even if their proteins are removed. e. Ribozymes catalyze formation of the fundamental linkage tying nucleic acids to proteins.

b. Ribozymes catalyze formation of bonds between amino acids in protein synthesis.

Some organisms are not able to live in an environment where there is oxygen; these types of organisms are called obligate anaerobes. Which explanation is most plausible for how they survive without oxygen? a. These organisms use photosynthesis to produce energy. b. Sulfur is used instead of oxygen because it is chemically similar. c. They are able to survive using less energy than aerobes. d. Their mitochondria are damaged, and consequently they are short-lived. e. All of their ATP is imported into the cell from an external source.

b. Sulfur is used instead of oxygen because it is chemically similar.

If the lacI repressor gene was permanently silenced by a DNA mutation, what would be the impact on the expression of the lac operon? a. There would be no impact on lac operon expression. b. The lac operon would always be expressed. c. The lac operon would only be expressed when lactose was present. d. The lac operon would never be expressed. e. The lac operon would only be expressed if glucose was absent.

b. The lac operon would always be expressed.

Why is there an upper limit to the surface area-to-volume ratio in a cell? a. The cells require a balance between endocytosis of precursor molecules to transporters in the membrane. b. The surface area must be sufficient to provide adequate nutrient and waste exchange to sustain the chemical activities of the cell. c. The organelles in cells require communication with the extracellular environment to support internal functions. d. The volume of the cell maximizes the use of phospholipids. e. The size of a cell is limited by the number of mitochondria.

b. The surface area must be sufficient to provide adequate nutrient and waste exchange to sustain the chemical activities of the cell.

Harry Noller's experiments in which he extracted the ribosomal proteins and found that RNA molecules could catalyze protein synthesis had one major flaw. What was the flaw? a. Coenzymes, which were not extracted, might have been responsible for the reaction. b. Undetectable amounts of protein may have remained. c. The extraction process may have altered the RNA molecules. d. The extraction process may have altered the pH of the environment. e. Protein synthesis may have occurred prior to extraction.

b. Undetectable amounts of protein may have remained.

Why is ubiquitin nicknamed the "doom tag"? a. When ubiquitin binds to a target protein, the ubiquitin enzyme degrades the protein. b. When ubiquitin binds to a target protein, the complex is sent to the proteasome and degraded. c. If a cell is deficient in ubiquitin, the cell will die. d. High levels of ubiquitin in a cell cause the cell to destroy vital proteins, leading to premature cell death. e. Ubiquitin binds to ribosomes and prevents them from translating proteins necessary for cell survival.

b. When ubiquitin binds to a target protein, the complex is sent to the proteasome and degraded.

β-galactosidase is used in bacterial screening assays for visualization of colonies that contain recombinant DNA. What is its substrate? a. agarose b. X-gal c. lacZ d. sucrose e. lactose

b. X-gal

Examine the pedigree in the figure above. Individuals affected by the genetic condition in question are indicated by filled squares or circles. Which inheritance pattern is most likely correct for this condition in this family? a. X-linked dominant b. X-linked recessive c. autosomal dominant d. cytoplasmic inheritance e. autosomal recessive

b. X-linked recessive

A recombinant phenotype is ____. a. the result of crossing two homozygous dominant individuals b. a different combination of the traits seen in either parent c. identical to the traits seen in both parents d. an expression of recessive traits only e. an expression of dominant traits only

b. a different combination of the traits seen in either parent

A neuron synthesizes and secretes substance D, which binds to a receptor on the neuron cell membrane, triggering an influx of calcium. Substance D therefore is a ligand for ____. a. guanylyl cyclase b. a ligand-gated ion channel c. a receptor tyrosine kinase d. a hormone receptor e. a G-protein-coupled receptor

b. a ligand-gated ion channel

Facilitated diffusion is specific, which indicates that ____. a. transport of molecules occurs only in specific cells b. a specific protein will transport certain polar or charged molecules but not others c. only specific hydrophobic molecules can be transported d. only one specific integral protein per membrane is involved in this process e. the energy molecule ATP is specifically required for transport

b. a specific protein will transport certain polar or charged molecules but not others

The proteome represents _____, while the cellular proteome represents _____. a. all of the proteins that are common to all living organisms; the proteins found in the same cell types of different species b. all of the proteins able to be expressed by an organism's genome; the subset of proteins found in a particular cell type c. the subject of proteomics research; the subject of phenomics research d. all of the proteins able to be made by all living organisms; the proteins made by unicellular organisms e. the set of proteins made by any multicellular organism; the set of proteins made by unicellular organisms

b. all of the proteins able to be expressed by an organism's genome; the subset of proteins found in a particular cell type

Deoxyribonucleotidesare included in the Sanger sequencing reaction mix to _____. a. enhance the activity of the dideoxyribonucleotides b. allow the production of multiple DNA fragments of different lengths c. allow longer DNA fragments (up to 300 additional base pairs)to be sequenced d. prevent the DNA polymerase from making too many errors e. provide a substrate for RNA polymerase

b. allow the production of multiple DNA fragments of different lengths

Individuals with extra or missing copies of one or more chromosomes are called ____. a. polyploids b. aneuploids c. diploids d. haploids e. euploids

b. aneuploids

In prokaryotes, high levels of cAMP ____. a. lead to CAP degradation b. are present when glucose levels are low c. are present when glucose levels are high d. promote CAP production e. negatively regulate the lac operon

b. are present when glucose levels are low

The two amino acids in the accompanying figure both have side groups ( R groups) that are ____. a. uncharged and polar b. basic and polar c. uncharged and nonpolar d. acidic and nonpolar e. acidic and polar http://cnow.apps.ng.cengage.com/ilrn/books/ru2bd04t/MTQA-83611_Images/ch03_image11.JPEG

b. basic and polar

The recognition of a chemical signal by a receptor protein in the membrane is most similar to ____. a. allosteric regulation of proteins b. binding of a specific substrate to the active site of an enzyme c. an enzyme requiring a specific optimum pH and temperature for activity d. turning on gene transcription e. mRNA specifying the sequence of amino acids in a polypeptide

b. binding of a specific substrate to the active site of an enzyme

Water has an important stabilizing effect on temperature in living organisms and their environments because as water absorbs heat, much of the energy is used to ____ instead of raising the temperature. a. create hydrogen bonds b. break hydrogen bonds c. create covalent bonds d. create hydration layers e. break surface tension

b. break hydrogen bonds

How do cells in the body of a multicellular organism communicate with each other? a. through long projections that directly connect cells to each other b. by way of signaling molecules that interact with specific receptors c. through electrical signals passed between a cell and its external environment d. by the transport of ions between cells in different parts of the organism e. by the transport of ions in water

b. by way of signaling molecules that interact with specific receptors

A fatty acid has a(n)____ group at the end of a hydrocarbon chain. a. hydroxyl group b. carboxyl group c. amino group d. carbonyl group e. phosphate group

b. carboxyl group

The breakdown of glucose into carbon dioxide, water, and ATP is an example of a(n) ____ pathway. a. anabolic b. catabolic c. endothermic d. endergonic e. cyclical

b. catabolic

The process by which cells break down complex molecules in the presence of oxygen to release energy is called ____. a. anabolism b. cellular respiration c. photosynthesis d. translation e. metabolism

b. cellular respiration

Helper proteins that assist in protein folding are called ____. a. polysomes b. chaperones c. spliceosomes d. ribosomes e. snRNPs

b. chaperones

Removing a nucleosome from DNA to expose a promoter is an example of ____. a. gene silencing b. chromatin remodeling c. induction d. posttranscriptional regulation e. dedifferentiation

b. chromatin remodeling

All the populations of different organisms that live in the same place form a(n) ____. a. biosphere b. community c. organ d. sample e. ecosystem

b. community

To study how genes have evolved, scientists compare the genome sequences of related organisms, a research approach known as _____. a. proteomics b. comparative genomics c. functional genomics d. genome annotation e. genome sequence determination

b. comparative genomics

Homologous chromosomes ____. a. are preserved in each daughter cell produced by meiosis b. contain a maternal and paternal chromosome c. are replicated during interkinesis d. are found in somatic cells and gametes e. align along the equatorial plane during metaphase II

b. contain a maternal and paternal chromosome

About 4% of individuals of Northern European descent are carriers for ____, an autosomal recessive genetic disorder in which a defective membrane transport protein leads to deficient chloride levels in extracellular fluids. a. Duchenne muscular dystrophy b. cystic fibrosis c. phenylketonuria d. sickle-cell anemia e. achondroplasia

b. cystic fibrosis

A testcross is used to ____. a. determine which allele is dominant b. determine if a parent with a dominant trait is heterozygous or homozygous c. prove an organism is true-breeding d. cross an individual with a dominant phenotype with a homozygous dominant individual to prove the alleles are dominant e. determine if the progeny of an experimental cross will have a random assortment of alleles

b. determine if a parent with a dominant trait is heterozygous or homozygous

When a drop of food coloring is placed in a container of clear water, the colored dye molecules ____. a. diffuse to a different location by active transport b. diffuse equally throughout the container c. diffuse to a different location by osmosis d. stay at the bottom of the container e. concentrate at the top of the container

b. diffuse equally throughout the container

The different alleles in human blood type are a demonstration of ____. a. dominance and incomplete dominance b. dominance and codominance c. dominance, codominance, and incomplete dominance d. codominance only e. incomplete dominance only

b. dominance and codominance

DNA replication is said to be semiconservative because ____. a. half of the DNA in a cell comes from one parent and the other half from the other parent b. each new DNA molecule is composed of one old strand and one new strand c. the number of nucleotides within genes remains constant d. the total amount of DNA within an individual remains the same e. the same process of DNA replication is used by all organisms

b. each new DNA molecule is composed of one old strand and one new strand

A(n) ____ gradient is created as ions diffuse across membranes. a. active b. electrochemical c. negative d. chemical e. electrical

b. electrochemical

Photosynthesis is ____, while all other processes of life are ____. a. exergonic; endergonic b. endergonic; exergonic c. endergonic; endothermic d. exergonic; endothermic e. exergonic; exothermic

b. endergonic; exergonic

According to the first law of thermodynamics, ____. a. matter can be created and destroyed b. energy only changes forms c. energy can be created and destroyed d. matter only changes forms e. matter and energy can be interconverted

b. energy only changes forms

In ____, genes at one locus mask the effect of genes at another locus. a. codominance b. epistasis c. polygenic inheritance d. incomplete dominance e. pleiotropy

b. epistasis

In which process are existing protein regions or domains mixed in novel combinations to produce new proteins? a. alternative splicing b. exon shuffling c. the wobble hypothesis d. degeneracy e. aminoacylation

b. exon shuffling

Insertion of two bases into the coding region of a gene just after the start codon of a gene will result in a ____ mutation. a. silent b. frameshift c. chromosomal d. missense e. nonsense

b. frameshift

Adjacent animal cells utilize ____ to rapidly communicate with each other. a. hormones b. gap junctions c. plasmodesmata d. neurotransmitters e. desmosomes

b. gap junctions

The technique by which DNA, RNA, or protein molecules are separated in a gel that is subjected to an electric field is called ____. a. a restriction enzyme digestion b. gel electrophoresis c. biotechnology d. PCR e. amplification

b. gel electrophoresis

According to the chromosome theory of inheritance, ____. a. genes are carried on chromosomes and alleles are the product of gene expression b. genes and their alleles are carried on chromosomes c. genes on chromosomes always assort independently d. maternal chromosomes determine the offspring's phenotype e. paternal chromosomes determine the offspring's phenotype

b. genes and their alleles are carried on chromosomes

When one parental allele is expressed and the other is silenced, the phenomenon is called ____. a. uniparental inheritance b. genomic imprinting c. sex-linked inheritance d. maternal inheritance e. cytoplasmic inheritance

b. genomic imprinting

Glucose biosynthesis is called _____. a. glycolysis b. gluconeogenesis c. fatty acid oxidation d. glyconeogenesis e. pentose phosphate pathway

b. gluconeogenesis

The main components of the extracellular matrix are ____. a. phospholipids b. glycoproteins c. cellulose d. glucose e. glycolipids

b. glycoproteins

In contrast to ionic bonds, covalent bonds ____. a. hold atoms together b. have distinct, three-dimensional forms c. are transient d. are rarely broken e. transfer electrons from one atom to another

b. have distinct, three-dimensional forms

When an individual has two different alleles for a given gene, they are ____ for that gene. a. self-fertilized b. heterozygous c. self-pollinated d. homozygous e. recessive

b. heterozygous

The prokaryotic chromosome is comprised of a ____. a. loosely folded mass of a single, circular molecule of DNA b. highly folded mass of a single, circular molecule of DNA c. loosely folded mass of a single, linear molecule of DNA d. highly folded mass of a double, circular molecule of DNA e. highly folded mass of a single, linear molecule of DNA

b. highly folded mass of a single, circular molecule of DNA

The two strands of a DNA double helix are held to each other by ____ bonds between nitrogenous bases. a. peptide b. hydrogen c. disulfide d. glycosidic e. phosphodiester

b. hydrogen

Answer the question using the accompanying figure. The molecule shown is held together by ____. a. van der Waals forces b. hydrogen bonds c. polar covalent bonds d. ionic bonds e. nonpolar covalent bonds http://cnow.apps.ng.cengage.com/ilrn/books/ru2bd04t/MTQA-83611_Images/ch02_image3.JPEG

b. hydrogen bonds

Reactions that use the equivalent of a water molecule to break a molecule into smaller subunits are called ____ reactions. a. dehydration synthesis b. hydrolysis c. equilibrium d. hydration e. redox

b. hydrolysis

Which functional group is polar and a key component of alcohols? a. amino b. hydroxyl c. carboxyl d. carbonyl e. phosphate

b. hydroxyl

An individual heterozygous for sickle-cell disease produces both normal and abnormal polypeptides. This is an example of ____. a. pleiotropy b. incomplete dominance c. multiple alleles d. epistasis e. polygenic inheritance

b. incomplete dominance

Suppose we hypothesize that potato plants use uncoupling proteins (UCPs) in a similar way as mammals. What would be the evidence to support this hypothesis? a. increased cytosolic pH b. increased internal tissue temperature c. increased amounts of ATP production d. decreased mitochondrial catabolism e. decreased sugar metabolism

b. increased internal tissue temperature

Enzymes function primarily by ____. a. changing the ratio of reactants to products so that the forward reaction is favored b. increasing the probability that the reactants will come into close proximity to each other in the proper orientation for forming the transition state molecule c. altering the equilibrium point of a particular reaction to favor the formation of products d. removing reactants from solution in a set ratio to increase the chances of the remaining individual reactants interacting with each other e. forcing the reactants into an altered environment which in turn creates a change in the free energy of the reactants relative to the products

b. increasing the probability that the reactants will come into close proximity to each other in the proper orientation for forming the transition state molecule

Which methodology was used by researchers to identify the nuclear localization sequence? a. transfection of cells in culture with mutant human proteins containing sequences believed to be required for nuclear localization followed by microscopic determination of cellular localization b. infection of cells in culture with viruses containing sequential deletions of amino acids in a protein known to localize to the nucleus, followed by microscopic determination of cellular localization c. treatment of cells in culture with pharmacological agents that inhibit the nuclear pore complex, followed by microscopic determination of cellular localization d. fluorescently labeling cells with known nuclear proteins and tracking changes in localization in the presence or absence of nuclear pore complex proteins e. treatment of cells in culture with pharmacological agents that binds to the nuclear localization sequence and prevents nuclear transport, followed by microscopic determination of cellular localization

b. infection of cells in culture with viruses containing sequential deletions of amino acids in a protein known to localize to the nucleus, followed by microscopic determination of cellular localization

How did researchers determine the proteins involved in the secretory pathway? a. genetically engineering mutations in genes and measuring changes in Golgi complex morphology b. interfering with the translation of proteins and examining the cell's ability to transport fluorescently tagged proteins c. treating cells with inhibitors of the secretory pathway and measuring changes in Golgi complex morphology d. adding a detergent to the cells to lyse the membranes and examining transport of fluorescently tagged proteins e. altering the pH of the media to selectively regulate different enzymes and measuring changes in Golgi complex morphology

b. interfering with the translation of proteins and examining the cell's ability to transport fluorescently tagged proteins

Quorum sensing ____. a. uses multiple cellular pathways to elicit a specific response b. is a type of communication between unicellular organisms c. allows receptors from different parts of the cell to work together to elicit a response d. allows receptors from different parts of the body to work together to elicit a response e. is a type of cell communication between multicellular organisms

b. is a type of communication between unicellular organisms

The width of a DNA double helix ____. a. is wider where purines are present than where pyrimidines are present b. is constant c. is wider where pyrimidines are present than where purines are present d. is narrower where adenine is present than where cytosine is present e. varies randomly

b. is constant

Mutagenesis ____. a. acts directly on proteins by causing them to unfold b. is the production of mutations in a laboratory by exposure of a living organism to a mutagen c. occurs due to a single mRNA being translated by too many ribosomes simultaneously d. occurs when errors made by DNA polymerase are not repaired e. is an example of spontaneous mutation

b. is the production of mutations in a laboratory by exposure of a living organism to a mutagen

Transcription of the lac operon is most efficient when ____. a. the CAP site of the promoter is not bound to cAMP b. lactose is present and glucose is absent c. lactose and glucose are present d. glucose is present and lactose is absent e. cAMP levels are low

b. lactose is present and glucose is absent

Sterol regulatory element binding proteins (SREBPs) are involved in regulating the synthesis of ____. a. carbohydrates b. lipids c. proteins d. amino acids e. nucleic acids

b. lipids

Transcription factors that control genes for developmental events are encoded by ____ genes. a. homeotic b. master regulator c. maternal effect d. activator e. Hox

b. master regulator

Bioinformatics combines the fields of ____ to extract information from biological data. a. biology and physics b. mathematics and computer science c. computer science and social science d. biology and history e. mathematics and social science

b. mathematics and computer science

The chromosome number is halved by ____ and restored by ____. a. meiosis; mitosis b. meiosis; fertilization c. mitosis; fertilization d. independent assortment; meiosis e. mitosis; meiosis

b. meiosis; fertilization

The voltage across a membrane is called the ____. a. chemical gradient b. membrane potential c. electrochemical gradient d. electron potential e. turgor pressure

b. membrane potential

The walls of adjacent plant cells are held together by the ____. a. cell membrane b. middle lamella c. secondary cell wall d. plasmodesmata e. primary cell wall

b. middle lamella

Aerobic cellular respiration occurs in the ____. a. Golgi complex b. mitochondria c. chloroplasts d. lysosomes e. peroxisomes

b. mitochondria

The chloroplast shares many similarities with which organelle? a. lysosome b. mitochondrion c. nucleus d. rough endoplasmic reticulum e. Golgi complex

b. mitochondrion

If an operon is regulated by ____ control, genes are ____ by a regulatory protein called a ____. a. positive; on unless they are switched off; activator b. negative; on unless they are switched off; repressor c. positive; on unless they are switched off; repressor d. positive; off unless they are switched on; repressor e. negative; off unless they are switched on; repressor

b. negative; on unless they are switched off; repressor

We can calculate whether a reaction is spontaneous by calculating the change in free energy and accounting for entropy. Your paycheck always lists your gross pay, net (take home) pay, and tax withholdings. Which of the following best correlates your paycheck to the changes in free energy? a. net salary = gross salary + tax; free energy = total energy + entropy b. net salary = gross salary - tax; free energy = total energy - entropy c. tax = gross - net salary; entropy = total energy - free energy d. gross salary = tax - net salary; total energy = entropy - free energy e. gross salary = net salary - tax; total energy = free energy - entropy

b. net salary = gross salary - tax; free energy = total energy - entropy

When does a CAM plant take in atmospheric CO2? a. daytime only b. nighttime only c. winter only d. anytime the Calvin cycle is occurring e. summer only

b. nighttime only

DNA is cut by ____. a. stem cells b. nucleases c. restriction fragment length polymorphisms d. Ti plasmids e. proteases

b. nucleases

Amplification of a signal increases as the ____. a. volume of the cell increases b. number of enzyme-catalyzed steps increases c. number of enzyme-catalyzed steps decreases d. volume of the cell decreases e. rate of reaction of the rate-limiting reaction increases

b. number of enzyme-catalyzed steps increases

In order to determine where a protein is expressed within a cell, a researcher tags the protein with a fluorescent label, and then views the cell using a fluorescent microscope. The location of the protein within the cell as determined by the researcher is considered the ____. a. experimental variable b. observed data c. experimental data d. replicate data e. predicted data

b. observed data

Synapsis refers to the ____. a. crossing-over between homologous chromosomes b. pairing of homologous chromosomes during prophase I c. alignment of sister chromatids along the equatorial plane d. pairing of sister chromatids during prophase II e. alignment of homologous chromosomes along the equatorial plane

b. pairing of homologous chromosomes during prophase I

In the IP3/DAG pathway, what is the effector molecule? a. PIP2 b. phospholipase C c. DAG d. IP3 e. calcium

b. phospholipase C

The major structural components of a cell membrane are ____. a. phospholipids and glycolipids b. phospholipids, protein, and sterols c. glycolipids and proteins d. phospholipids and cellulose e. protein and sterols

b. phospholipids, protein, and sterols

In prokaryotes, photosynthesis occurs in the ____. a. chloroplasts b. plasma membrane c. mitochondria d. nucleoid e. ribosomes

b. plasma membrane

Which group would be considered a community? a. fish, birds, alligators, water b. polar bears, seals, fish c. a group of seaweed d. a group of alligators e. pandas, bamboo, mountains

b. polar bears, seals, fish

Pepsin, a digestive enzyme that degrades proteins in the stomach, is synthesized as pepsinogen and converted to active pepsin in the stomach by the removal of several amino acids. The activation of pepsin is an example of ____. a. posttranscriptional regulation b. posttranslational regulation c. transcriptional regulation d. RNAi e. translational regulation

b. posttranslational regulation

The TATA box is a key element of the ____ of most eukaryotic protein-coding genes. a. introns b. promoter c. coding region d. transcription start point e. terminator

b. promoter

Homologous chromosomes undergo recombination during ____. a. metaphase II b. prophase I c. metaphase I d. prophase II e. both prophase I and II

b. prophase I

Cytoskeletal elements are assembled from ____. a. phospholipids b. proteins c. triglycerides d. glycogen e. nucleotides

b. proteins

Which class of molecule is the most diverse in terms of structure and roles played in cells? a. lipids b. proteins c. nucleic acids d. amino acids e. carbohydrates

b. proteins

An unmutated version of an oncogene in a normal cell is called a ____. a. tumor suppressor gene b. proto-oncogene c. growth-inhibiting factor gene d. driver gene e. pre-oncogene

b. proto-oncogene

In order for a target cell to receive a signal, it must possess a ____ specific to the signaling molecule. a. glycolipid b. receptor c. glycoprotein d. hormone e. transfer protein

b. receptor

In patients with familial hypercholesterolemia, which cellular process is inhibited? a. secondary active transport b. receptor mediated endocytosis c. primary active transport d. exocytosis e. bulk endocytosis

b. receptor mediated endocytosis

Multigene families arise from _____. a. deletions of genes b. repeated cycles of gene duplication followed by mutation c. single point mutations d. exon shuffling e. a single gene duplication event

b. repeated cycles of gene duplication followed by mutation

The ____ is/are involved in the synthesis of lipids. a. ribosomes b. smooth endoplasmic reticulum c. nucleoli d. rough endoplasmic reticulum e. Golgi complex

b. smooth endoplasmic reticulum

The most fundamental grouping in the classification of living organisms is the ____. a. family b. species c. class d. order e. genus

b. species

Which plant structure is responsible for gas exchange? a. thylakoid b. stomata c. stroma d. grana e. stromal lamellae

b. stomata

An example of a nonpolar signaling molecule is ____. a. growth factors b. testosterone c. epinephrine d. neurotransmitters e. insulin

b. testosterone

The two strands of a DNA double helix are said to be antiparallel. This means that ____. a. since the double helix twists, it is not perfectly parallel b. the 5' end of one strand is directly paired with the 3' end of the other strand c. both strands have a negative charge d. one strand has a negative charge and the other strand has a positive charge e. the 5' end of one strand is directly paired with the 5' end of the other strand

b. the 5' end of one strand is directly paired with the 3' end of the other strand

Which region(s) of the ribosome accept(s) charged tRNA molecules during the elongation phase of translation? a. the A site or the E site b. the A site c. the E site d. the P site e. the P site or the E site

b. the A site

Where do exocytic secretory vesicles originate? a. plasma membrane b. the Golgi complex c. lysosomes d. endoplasmic reticulum e. microbodies

b. the Golgi complex

Which function of cellular membranes is critical to the ionic and molecular organization of cells? a. reception of chemical signals from other cells b. the controlled transport of ions and molecules across the membrane c. recognition of other cells as being "foreign" or "self" d. cell-cell binding e. participation in metabolic reactions

b. the controlled transport of ions and molecules across the membrane

Polygenic inheritance is often modified by ____. a. epistasis b. the environment c. gene blending d. dihybrid crosses e. pleiotropy

b. the environment

Two structural differences between a uridine monophosphate and thymidine monophosphate are ____ and ____. a. the number of hydrogen bonds formed between it and its matching base; the presence of a hydroxyl group on the ribose b. the presence of a methyl group on the nitrogen base; the presence of a hydroxyl group on the ribose c. the number of hydrogen bonds formed between it and its matching base; the presence of a methyl group on the nitrogen base d. the presence of a methyl group of the nitrogen base; the location of the ribose attachment to the nitrogenous base e. the number of hydrogen bonds formed between it and its matching base; the location of the ribose attachment to the nitrogenous base

b. the presence of a methyl group on the nitrogen base; the presence of a hydroxyl group on the ribose

James Watson, Francis Crick, Rosalind Franklin, and Maurice Wilkins are recognized for their contributions to the discovery of the ____. a. location of DNA in cells b. three-dimensional structure of DNA c. chemical components of DNA d. role of DNA in cells e. presence of nuclein (DNA) in white blood cells

b. three-dimensional structure of DNA

In DNA, the pyrimidines are ____. a. guanine and thymine b. thymine and cytosine c. adenine and guanine d. adenine and cytosine e. thymine and adenine

b. thymine and cytosine

The final step of the citric acid cycle oxidizes malate to oxaloacetate and reduces NAD+. What is the purpose of this step? a. to produce ATP by oxidative phosphorylation b. to regenerate oxaloacetate to attach another acetate molecule c. to replenish the supplies of NAD+ d. to replenish free CoA e. to produce ATP by substrate-level phosphorylation

b. to regenerate oxaloacetate to attach another acetate molecule

The membrane that surrounds the central vacuole is the ____. a. chromoplast b. tonoplast c. chloroplast d. amyloplast e. ionoplast

b. tonoplast

What is the second step of signal transduction? a. division b. transduction c. reception d. response e. differentiation

b. transduction

Which proteins form channels in the membrane that allow selected polar molecules and ions to pass through and across the membrane? a. recognition proteins b. transport proteins c. cell adhesion proteins d. nuclear proteins e. receptor proteins

b. transport proteins

Recombination at the synaptonemal complex always results in ____. a. four changed chromatids b. two changed and two unchanged chromatids c. a random number of changed vs. unchanged chromatids d. four unchanged chromatids e. one unchanged and three changed chromatids

b. two changed and two unchanged chromatids

Assuming a single cross-over event, the completion of meiosis produces ____. a. three daughter cells with parental chromosomes and one daughter cell with a recombinant chromosome b. two daughter cells with parental chromosomes and two daughter cells with recombinant chromosomes c. two daughter cells, each with recombinant chromosomes d. one daughter cell with parental chromosomes and one cell with recombinant chromosomes e. four daughter cells with recombinant chromosomes

b. two daughter cells with parental chromosomes and two daughter cells with recombinant chromosomes

Events X and Y are independent of each other. If the probability of event X occurring is 1 in 4, and the probability of event Y occurring is 1 in 5, the probability of both events occurring is ____. a. (1/4)2 + (1/5)2 = (1/16) + (1/25) = (25/400) + (16/400) = 41/400 b. (1/4) + (1/5) = (5/20) + (4/20) = 9/20 c. (1/4)(1/5) = 1/20 d. (1/4 + 1/5)2 = (5/20 + 4/20)2 = (9/20)2 = 81/400 e. (1/4)2(1/5)2 = (1/16)(1/25) = 1/400

c. (1/4)(1/5) = 1/20

A cross is performed between parents with genotypes aaBbCc and aaBbcc. What is the probability that the offspring will have the same genotype as the first parent? Assume that capital letters indicate dominant alleles and lower case letters indicate recessive alleles. a. 9/16 b. 1/8 c. 1/4 d. 3/16 e. 3/8

c. 1/4

Answer the question using the accompanying figure. The electrons at the lowest energy level in the neon atom depicted are found in which orbital? a. 2py b. 2s c. 1s d. 2pz e. 2px http://cnow.apps.ng.cengage.com/ilrn/books/ru2bd04t/MTQA-83611_Images/ch02_image2.JPEG

c. 1s

If a species has 42 pairs of chromosomes, how many maternal and paternal chromosome combinations are possible during independent assortment? a. 2^21 b. 42^2 c. 2^42 d. 84^2 e. 21^2

c. 2^42

Consider the DNA sequence 5'-GATTACA-3'. If the strand with this sequence forms a double helix with another DNA strand, the sequence on the other strand should be ____. a. 5'-TCGGCAC-3' b. 3'-GTGCCGA-5' c. 3'-CTAATGT-5' d. 5'- ACATTAG-3' e. 3'-GATTACA-5'

c. 3'-CTAATGT-5'

A molecule of water in the middle of a chunk of ice will usually have ____ hydrogen bonds with other water molecules. a. 2 b. 6 c. 4 d. 3 e. 3.4

c. 4

In Drosophila melanogaster, the allele for red eyes is dominant over the allele for purple eyes, and the allele for a gray body is dominant over the allele for a black body. A testcross was done to check for genetic linkage between the genes for these traits. The results for the offspring are listed below: 478 flies with red eyes and a gray body 27 flies with red eyes and a black body 462 flies with purple eyes and a black body 33 flies with purple eyes and a gray body Which of the choices below best represents the map distance between the genes for these two traits? a. 47.0 map units b. 50.0 map units c. 6.0 map units d. 27.0 map units e. 30.0 map units

c. 6.0 map units

Which two nucleotides also serve as transporters of chemical energy? a. ATP and CTP b. ATP and TTP c. ATP and GTP d. CTP and UTP e. CTP and TTP

c. ATP and GTP

Two genes (A and B) are located on each of two pairs of homologous chromosomes. In a tetrad, one sister chromatid contains alleles ab, while the other sister chromatid contains alleles AB (upper and lower case indicate different alleles of the same gene). Which genetic combinations are possible in the four gametes that are produced from a single chiasma between these chromosome pairs? a. Aa, Bb, ab, Ab b. Ab, Ab, AB, AB c. Ab, AB, ab, aB d. AB, AB, ab, ab e. Ab, Ab, aB, aB

c. Ab, AB, ab, aB

During a DNA sequencing experiment, the researcher adds all the required components to the reaction but accidentally adds only one of the four dideoxynucleotides, the ddC. What products will be observed after this reaction is complete? a. All fragments will end in G. b. All fragments will end in A. c. All fragments will end in C. d. All fragments will end in T. e. No fragments will be made.

c. All fragments will end in C.

Answer the question using the accompanying graph. Which portion of the graph shows the activation energy in the presence of enzyme? a. W + X b. C c. B d. A e. Y + Z

c. B

Mouse pigmentation is subject to epistasis of the B alleles by the d alleles. B (black) is dominant over b (brown), and D is dominant over d. Homozygous d is epistatic to the black and brown genes. Given this information, what genotype(s) result in a white mouse (no pigment)? a. Bbdd only b. bbDd only c. BBdd and Bbdd d. bbDD only e. BBdd only

c. BBdd and Bbdd

Which domain(s) have densely packed genomes with little noncoding space? a. Bacteria only b. Eukarya only c. Bacteria and Archaea d. Archaea and Eukarya e. Archaea only

c. Bacteria and Archaea

Which of these hydrocarbons has a double bond in its structure? a. C3H8 b. CH4 c. C2H4 d. C2H6 e. C2H2

c. C2H4

The large, double-stranded, helical molecule that contains instructions for assembling a living organism from simpler molecules is ____. a. ATP b. protein c. DNA d. RNA e. NADPH

c. DNA

Chromatin consists of ____. a. only DNA b. RNA only c. DNA and associated proteins d. proteins only in the nucleus e. DNA and RNA

c. DNA and associated proteins

Recombinant DNA is ____. a. a plasmid containing DNA from a single source b. a gene of interest found in the genome c. DNA fragments from two or more different sources that have been joined together to form a single molecule d. DNA encoding restriction endonucleases e. DNA fragments from the same organism that have been joined together to form a single molecule

c. DNA fragments from two or more different sources that have been joined together to form a single molecule

A researcher wants to insert a DNA fragment into a plasmid. Which enzyme will join the two DNA molecules together? a. primase b. DNA polymerase c. DNA ligase d. restriction endonuclease e. β-galactosidase

c. DNA ligase

Proofreading by ____ corrects errors that occur during DNA replication. a. telomerase b. helicase c. DNA polymerase d. DNA ligase e. primase

c. DNA polymerase

We study cellular respiration because it is one of the most important pathways in biology. In fact, nearly all carbohydrates at some point in their catabolism are directed through cellular respiration. Why is it unnecessary to have multiple independent pathways to break down different molecules? a. Greater complexity would lead to an eventual failure of the biological system. b. Using cellular respiration is theoretically the most efficient way to break down sugars and other molecules. c. Energy-containing macromolecules can be converted to products that can enter at various points in the cellular respiration pathway. d. Most biological cells only catabolize one or two different types of sugars and only need one main pathway. e. Oxygen must be used in the breakdown of all molecules in order to yield ATP.

c. Energy-containing macromolecules can be converted to products that can enter at various points in the cellular respiration pathway.

More than 60% of all prescribed drugs target ____, due to their wide physiological impact. a. hormone receptors b. ligand-gated ion channels c. G-protein-coupled receptors d. receptor tyrosine kinases e. guanylyl cyclase

c. G-protein-coupled receptors

Energy for the three stages of translation is directly provided by ____. a. fats b. sugars c. GTP d. dNTP e. ATP

c. GTP

Why is it important to have an antibiotic resistance gene in plasmid cloning vectors? a. It helps the host bacteria grow faster. b. It allows researchers to distinguish bacteria that contain the recombinant vector from those that contain just the vector. c. It allows researchers to distinguish bacteria that contain the plasmid from those that do not. d. It aids scientists in developing new antibiotic treatments. e. It helps the bacteria replicate the recombinant plasmid more quickly.

c. It allows researchers to distinguish bacteria that contain the plasmid from those that do not.

What is the relationship between operators, transcription units, and operons? a. Operons consist of multiple operators associated with a single transcription unit. b. Operators consist of multiple transcription units associated with a single operon. c. Operons consist of transcription units and operators. d. Operators consist of transcription units and operons. e. Operons consist of multiple transcription units associated with a single operator.

c. Operons consist of transcription units and operators.

Ribozymes are ____. a. the products of RNA degradation b. RNA molecules that slow the rate of protein synthesis c. RNA catalysts d. proteins that catalyze RNA synthesis e. amino acids that catalyze RNA synthesis

c. RNA catalysts

During normal DNA replication, part of the sequence at the ends of linear chromosomes is not copied into the new DNA strands because ____. a. cells do not need the DNA at the ends of chromosomes b. the ends of chromosomes are made of protein, not DNA c. RNA primers at the beginning of a new strand cannot be replaced with DNA d. those ends are Okazaki fragments that are lost e. DNA ligase cannot join pieces at the end of a chromosome

c. RNA primers at the beginning of a new strand cannot be replaced with DNA

The individual credited with first observing the cell nucleus is ____. a. Matthias Schleiden b. Theodor Schwann c. Robert Brown d. Anton van Leeuwenhoek e. Rudolf Virchow

c. Robert Brown

What happens when the concentrations of a solute that can freely diffuse across a membrane are equal inside and outside the cell? a. The osmotic pressure is equilibrated on both sides of the membrane. b. Channel proteins are gated to prevent movement across the membrane. c. Solute molecules continue to diffuse across the membrane. d. Transporter proteins are inhibited to prevent movement across the membrane. e. Solute molecules no longer diffuse across the membrane.

c. Solute molecules continue to diffuse across the membrane.

In the accompanying figure, why does the curve sharply drop after approximately 45 ° C instead of mirroring the slope of the line going from 0 - 40 ° C? a. The kinetic energy of the reactants is lower than that of the products, forcing a change in enzyme activity. b. This is true of all catalysts and is not due to any special features of enzymes. c. The enzyme begins to denature above a certain temperature, eliminating all catalytic activity of the protein. d. The kinetic energy of the reactants is so great that it destabilizes the enzyme and diminishes the enzyme's activity. e. At high temperatures, the reactions proceed so quickly that enzymes are no longer helpful or required.

c. The enzyme begins to denature above a certain temperature, eliminating all catalytic activity of the protein.

Why is DNA ligase most active on the lagging strand during DNA replication? a. The lagging strand synthesizes DNA in the 3' → 5' direction. b. The lagging strand requires DNA ligase to couple the RNA primer to the Okazaki fragments. c. The lagging strands contain more short DNA segments than the leading strand, which are joined together by DNA ligase. d. The lagging strand is synthesized more slowly, and DNA ligase speeds up the DNA polymerase. e. DNA ligase performs the function of RNA primase on the lagging strand.

c. The lagging strands contain more short DNA segments than the leading strand, which are joined together by DNA ligase.

In the whole-genome shotgun method, the genome is fragmented and individual fragments are sequenced. How is the order of the nucleotides determined for the original intact chromosome? a. The fragmentation is done in a systematic way such that the physical arrangement of fragments is readily apparent. b. After sequencing, the fragments are labeled and used as probes in a microarray. c. The random fragmentation produces overlapping sequences that can be aligned and assembled to generate the original intact DNA molecule. d. We supplement our information with data from a different technique to determine the final chromosome arrangement. e. DNA hybridization assays are conducted to determine the physical arrangement of the genes on the chromosome.

c. The random fragmentation produces overlapping sequences that can be aligned and assembled to generate the original intact DNA molecule.

You do an experiment in the laboratory and add increasing amounts of substrate to a solution containing an enzyme and a pH buffer. You incubate the container at the optimal temperature for your enzyme. Each time you add more substrate, you measure the rate of the reaction. If you graph the results with substrate concentration on the x-axis and reaction rate on the y-axis, what will you find over time? a. The rate of the reaction will increase slowly, plateau, and then drop sharply back to zero. b. There is no way to predict what the graph will look like without more information. c. The rate of the reaction will increase rapidly, taper off, and plateau. d. The resulting graph will be a perfect bell curve. e. The rate of the reaction will proceed with a slope of 1 and continue in a linear fashion indefinitely or until you run out of reactants.

c. The rate of the reaction will increase rapidly, taper off, and plateau.

How do scientists most often access genome sequences determined by research projects? a. They must request the sequence from the governmental or private group that funded the research. b. They must request the sequence from the group that performed the research. c. They can retrieve the sequence from an online public database, such as GenBank. d. They must sequence the organism themselves to obtain the sequence. e. They must request the sequence from the company that performed the sequencing.

c. They can retrieve the sequence from an online public database, such as GenBank.

Why are trans fats more harmful for consumption than saturated fats? a. Saturated fats are more natural, and better digested in the gut. b. Saturated fats prevent LDL transport more than trans fats. c. Trans fats decrease HDL cholesterol levels more than saturated fats. d. Trans fats increase LDL cholesterol levels more than saturated fats. e. Trans fats are often consumed with other food additives that increase fat absorption in the gut.

c. Trans fats decrease HDL cholesterol levels more than saturated fats.

Wilkins and Franklin studied the structure of DNA using ____. a. molecular scale models of nucleotides b. light microscopy c. X-ray diffraction d. electron microscopy e. computer-assisted graphics

c. X-ray diffraction

If you see a male calico cat, you can be fairly certain that his diploid cells have a sex chromosome combination of ____. a. XX b. XY c. XXY d. XO e. XYY

c. XXY

The formation and breaking of bonds between atoms requires ____. a. van der Walls forces b. an empty valence shell c. a chemical reaction d. partial charges e. an enzyme

c. a chemical reaction

Which pattern of diploid and haploid phases reflects the life cycle in animals? a. a single generation that limits the diploid state to gametes while the rest of the organism is haploid b. alternation between haploid and diploid generations c. a single generation that limits the haploid state to gametes while the rest of the organism is diploid d. one haploid generation followed by two diploid generations e. two haploid generations followed by a diploid generation

c. a single generation that limits the haploid state to gametes while the rest of the organism is diploid

Microfilaments are assembled from ____. a. myosin b. keratin c. actin d. laminin e. tubulin

c. actin

Movement of a substance from an area of low concentration to an area of high concentration using energy obtained from ATP is called ____. a. osmosis b. passive transport c. active transport d. diffusion e. facilitated transport

c. active transport

Gap junctions ____. a. give the cell its shape b. allow plant cells to communicate with each other c. allow ions and small molecules to pass between cells d. anchor the cell membrane to the cell wall e. seal the spaces between cells

c. allow ions and small molecules to pass between cells

Multiple hydrogen bonds together stabilize proteins into a spiral structure called a ____. a. water lattice b. delta plus c. alpha helix d. delta minus e. chemical groups

c. alpha helix

Which pre-mRNA processing mechanism allows different proteins to be produced from the same DNA sequence? a. intron shuffling b. transposition c. alternative splicing d. intron splicing e. open reading frame shuffling

c. alternative splicing

In plant cells, starch is stored in ____. a. vacuoles b. chloroplasts c. amyloplasts d. leucoplasts e. chromoplasts

c. amyloplasts

A cell is minimally defined by ____. a. specialized molecules that respond to their environment b. an organized chemical system for harnessing energy c. an organized chemical system and specialized molecules surrounded by a membrane d. a nucleus that contains DNA e. a membrane comprised of phospholipids

c. an organized chemical system and specialized molecules surrounded by a membrane

What is the function of the sliding clamp in DNA replication? a. anchor primase to the template strand b. bind to single-stranded DNA to stabilize it before it is replicated c. anchor DNA polymerase to the template strand d. remove DNA polymerase from the template strand e. unwind DNA ahead of the replication fork

c. anchor DNA polymerase to the template strand

Desmosomes are a type of ____. a. tight junction b. intermediate filament c. anchoring junction d. cell adhesion molecule e. gap junction

c. anchoring junction

The region in a tRNA molecule that base-pairs with mRNA during translation is the ____. a. cloverleaf b. reading frame c. anticodon d. TATA box e. aminoacylation site

c. anticodon

The smallest unit that retains the chemical and physical properties of an element is a(n) ____. a. molecule b. compound c. atom d. proton e. neutron

c. atom

A polar covalent bond would be most likely to form between ____. a. atoms with filled valence shells b. atoms with partial positive and partial negative charges c. atoms with different electronegativities d. atoms of the same element e. cations and anions

c. atoms with different electronegativities

Examine the pedigree in the accompanying figure. Individuals affected by the genetic condition in question are indicated by filled squares or circles. Which inheritance pattern is most likely correct for this condition in this family? a. X-linked dominant b. autosomal recessive c. autosomal dominant d. cytoplasmic inheritance e. X-linked recessive

c. autosomal dominant

In RNAi, imperfect pairing of miRNA to target mRNA results in ____ while perfect pairing of miRNA to target mRNA causes ____. a. blocking transcription of the target mRNA; mRNA degradation b. mRNA degradation; recruitment of siRNA c. blocking translation of the target mRNA; mRNA degradation d. recruitment of siRNA; blocking translation of the target mRNA e. blocking transcription of the target mRNA; blocking translation of the target mRNA

c. blocking translation of the target mRNA; mRNA degradation

Identify the exergonic reaction in the list below. a. building a tower out of blocks b. synthesizing a protein c. burning wood for a campfire d. folding laundry e. storing the third slice of pie in the form of fat

c. burning wood for a campfire

Chemical compounds released during tobacco use can cause ____. a. hemophilia b. cystic fibrosis c. cancer d. sickle-cell anemia e. color blindness

c. cancer

Which functional group forms the highly reactive part of aldehydes and ketones? a. phosphate b. hydroxyl c. carbonyl d. carboxyl e. amino

c. carbonyl

Which protein group links cells together by recognizing and binding receptors or chemical groups on other cells or the extracellular matrix? a. nuclear proteins b. transport proteins c. cell adhesion proteins d. recognition proteins e. receptor proteins

c. cell adhesion proteins

The action spectrum of higher plants is bimodal, with two major peaks. Which two molecules largely determine the two peaks? a. P680 and P700 b. chlorophyll and carotenoid c. chlorophyll a and chlorophyll b d. ATP and NADH e. photosystems I and II

c. chlorophyll a and chlorophyll b

Substance B is synthesized in neurons, travels through gap junctions, and triggers the transduction of an electrochemical signal. This is an example of ____. a. local signaling b. autocrine signaling c. communication by direct contact d. long-distance signaling e. paracrine signaling

c. communication by direct contact

The purpose of the Calvin cycle is to ____. a. generate the O2 gas required for cellular respiration b. recover electrons lost when water was split c. convert inorganic carbon into a useable form of carbon d. counteract increasing atmospheric CO2 concentrations (global warming) e. capture photons of light to harvest solar energy

c. convert inorganic carbon into a useable form of carbon

Which amino acid can be involved in special covalent "disulfide bridges" that, when present, help to stabilize the tertiary and quaternary structure of proteins? a. leucine b. alanine c. cysteine d. methionine e. proline

c. cysteine

Reactions that remove the equivalent of a water molecule when subunits are joined to make a larger molecule are called ____ reactions. a. hydrolysis b. redox c. dehydration synthesis d. equilibrium e. hydration

c. dehydration synthesis

The E. coli lac operon encodes three genes. These genes ____. a. cleave lactose into glucose and galactose, produce transacetylase, and actively transport lactose into the cell b. encode an enzyme that cleaves glucose, a transport protein for active transport, and a transacetylase enzyme for solubilizing lactose in the cytosol c. encode an enzyme that cleaves lactose, a transport protein for active transport of lactose, and a transacetylase enzyme whose function is unknown d. catalyze the synthesis of lactose from glucose and galactose, produce transacetylase, and actively export lactose from the cell e. directly interact with the Lac repressor and initiate their own transcription

c. encode an enzyme that cleaves lactose, a transport protein for active transport of lactose, and a transacetylase enzyme whose function is unknown

The C4 cycle ____. a. replaces the second stage of the Calvin cycle b. is more efficient than the Calvin cycle because less ATP is consumed in the process c. ensures that CO2 is provided to rubisco and thus prevents photorespiration d. is most commonly associated with plants living in humid climates e. supplements the activity of rubisco by providing a second source of 3PGA for the reduction stage of the Calvin cycle

c. ensures that CO2 is provided to rubisco and thus prevents photorespiration

Which molecules integrate changes outside and inside the cells through communicating changes in the extracellular matrix to the cytoskeleton? a. fibronectin and collagen b. gap junctions and proteoglycans c. fibronectin and integrin d. collagen and integrin e. gap junctions and fibronectin

c. fibronectin and integrin

The sugar in DNA is comprised of ____ carbons. a. six b. three c. five d. four e. seven

c. five

How might a researcher best determine the location of a protein in a cell? a. studying the amino acid sequence of the protein b. analyzing the untranslated regions of the gene encoding the protein c. fusing a fluorescent tag to the protein to visualize its cellular location under a microscope d. attaching an antibiotic tag to the protein and determining its location using DNA microarrays e. understanding the protein's function

c. fusing a fluorescent tag to the protein to visualize its cellular location under a microscope

In the process of aerobic metabolism, carbon-containing molecules are broken down and the energy from the electrons is used to ____. a. alter enzyme structure b. directly supply the energy needs of an organism c. generate a proton gradient d. supply heat to stored fat e. heat the organism in a cold environment

c. generate a proton gradient

Which cellular response follows activation of a ligand-gated ion channel? a. activation of a phosphorylation cascade b. direct regulation of gene expression c. generation of an electrical signal d. activation of a second messenger pathway e. direct activation of a kinase

c. generation of an electrical signal

From his experiments, Mendel concluded that each individual carries two factors, or ____, that govern the inheritance of each trait. Different versions of each factor are known as ____. a. alleles; gene markers b. genes; loci c. genes; alleles d. gene markers; genes e. alleles; genes

c. genes; alleles

Most genetic alterations performed by researchers aim to change the ____. a. proteome of the organism without a change in genotype b. phenotype of the organism without a change in genotype c. genotype of the organism, causing a change in phenotype d. phenotype of the organism, causing a change in genotype e. genotype of the organism without a change in phenotype

c. genotype of the organism, causing a change in phenotype

The scientific name of an organism is composed of two names. The first part identifies the ____ while the second part designates the ____. a. phylum; species b. family; genus c. genus; species d. genera; genus e. species; genus

c. genus; species

Which molecule associated with photorespiration is toxic to plant cells? a. rubisco b. G3P c. glycolate d. 3PGA e. phosphoglycolate

c. glycolate

NO binds to and activates____ to trigger its cellular response. a. receptor tyrosine kinase b. G-protein coupled receptors c. guanylyl cyclase d. adenylyl cyclase e. MAPK

c. guanylyl cyclase

Chemical bonds that are formed when one atom with a partial positive charge (created from unequal sharing of electrons) is electrically attracted to another atom with a partial negative charge (also created from unequal sharing of electrons) are called ____. a. van der Waals forces b. ionic bonds c. hydrogen bonds d. nonpolar covalent bonds e. polar covalent bonds

c. hydrogen bonds

The water lattice illustrated in the figure above forms as a result of ____ between water molecules. a. van der Walls forces b. covalent bonds c. hydrogen bonds d. ionic bonds e. nonpolar interactions

c. hydrogen bonds

The energy to form the new bonds between nucleotides in a growing DNA strand is provided primarily by ____. a. unwinding of the DNA double helix b. breaking hydrogen bonds between base pairs c. hydrolysis of pyrophosphate d. DNA helicase e. forming hydrogen bonds between base pairs

c. hydrolysis of pyrophosphate

In the presence of water, nonpolar associations form between molecules or regions of molecules that are ____. a. partially charged b. hydrophilic c. hydrophobic d. fully charged e. hydrophobic and hydrophilic

c. hydrophobic

Where would you expect to find proteins responsible for controlling the substances that enter and leave mitochondria? a. outer mitochondrial membrane b. nuclear membrane c. inner mitochondrial membrane d. lysosomal membrane e. plasma membrane of the cell

c. inner mitochondrial membrane

In molecules, the constant motion of the atoms is an example of ____ energy, while the arrangement of atoms and bonds is an example of ____ energy. a. kinetic; chemical b. potential; chemical c. kinetic; potential d. chemical; free e. potential; free

c. kinetic; potential

The sequential stages through which individuals develop, grow, maintain themselves, and reproduce are collectively known as the ____. a. central dogma b. anabolic reactions c. life cycle d. catabolic reactions e. transformation

c. life cycle

When DNA fragments are sealed together by DNA ligase, the process is referred to as ____. a. the polymerase chain reaction b. restriction cloning c. ligation d. transformation e. gene remodeling

c. ligation

The chemical structure of chlorophyll is based on a complex organic ring structure, with a long hydrophobic side chain and a(n) ____ atom in the center of the ring. a. manganese b. nitrogen c. magnesium d. iron e. carbon

c. magnesium

You are studying an ecosystem on your campus. After a solid base of carefully observed and described facts, your next step would be to ____. a. make more observations b. wait for instructions c. make a hypothesis d. design an experiment e. share your data with others

c. make a hypothesis

The term that best describes all of the chemical reactions of a cell, including acquisition and use of molecules and energy, is ____. a. thermodynamics b. catabolism c. metabolism d. anabolism e. energy budget

c. metabolism

Karyotype analyses are performed on cells in ____ of mitosis. a. prometaphase b. telophase c. metaphase d. prophase e. anaphase

c. metaphase

A bundle of ____ extends from the base to the tip of a eukaryotic flagellum or cilium. a. cytokeratin b. microfilaments c. microtubules d. intermediate filaments e. actin

c. microtubules

Substitution of one base pair for another in a coding region of a gene can result in a ____ mutation where the changed codon specifies a different amino acid. a. frameshift b. nonsense c. missense d. chromosomal e. silent

c. missense

The genetic code is said to be degenerate because ____. a. the code is commaless, with no indicators of spaces between codons b. the code varies considerably between different cell types within a multicellular organism c. most amino acids are represented by more than one codon d. some codons do not specify an amino acid e. the code varies considerably between different organisms

c. most amino acids are represented by more than one codon

Purines and pyrimidines are ____. a. nucleic acids b. pentose-phosphate backbones c. nitrogenous bases d. Okazaki fragments e. phosphate bases

c. nitrogenous bases

In cell fractionation, which cellular structure or molecule is isolated in a pellet after the first centrifugation? a. nucleic acids b. ribosomes c. nuclei d. proteins e. mitochondria

c. nuclei

Hereditary information in all eukaryotes, prokaryotes, and viruses is stored in ____. a. amino acids b. lipids c. nucleic acids d. carbohydrates e. proteins

c. nucleic acids

The semiliquid substance within the nucleus is called ____. a. chromatin b. protoplasm c. nucleoplasm d. cytoplasm e. nuclear gel

c. nucleoplasm

Pre-mRNA is found____. a. in both the nucleus and cytoplasm of eukaryotes b. only in the cytoplasm of eukaryotes c. only in the nucleus of eukaryotes d. only in prokaryotes e. in both prokaryotes and eukaryotes

c. only in the nucleus of eukaryotes

During transcription, ____. a. primase creates an RNA primer to start the RNA strand b. the entire DNA molecule is copied to RNA c. only one of the two DNA strands acts as a template d. protein is made from RNA e. double-stranded RNA chains are produced

c. only one of the two DNA strands acts as a template

During glycolysis, glucose molecules are broken down by breaking the carbon-hydrogen bonds that are present and forming carbon-oxygen bonds. In this process, glucose is ____. a. completely oxidized b. completely reduced c. partially oxidized d. hydrolyzed e. partially reduced

c. partially oxidized

The formation of peptide bonds during translation is catalyzed by ____ found in the ____. a. aminoacyl-tRNA synthetase; small ribosomal subunit b. peptidyl transferase; small ribosomal subunit c. peptidyl transferase; large ribosomal subunit d. aminoacyl-tRNA synthetase; tRNA e. RNA polymerase; large ribosomal subunit

c. peptidyl transferase; large ribosomal subunit

Researcher A studies the protein interactions involving the polypeptides that comprise hemoglobin, while Researcher B studies protein interactions between a protein kinase and its target protein. Researcher A will therefore focus on ____, and researcher B will focus on ____. a. protein regulation; transcriptional regulation b. protein localization; protein sequence c. permanent protein interactions; transient protein interactions d. protein sequence; protein localization e. transient protein interactions; permanent protein interactions

c. permanent protein interactions; transient protein interactions

The molecule shown above is a(n) ____. a. steroid b. triglyceride c. phospholipid d. amino acid e. polysaccharide

c. phospholipid

The initial step of glycolysis involves the ____ of glucose. a. oxidation b. reduction c. phosphorylation d. hydrolysis e. condensation

c. phosphorylation

A group of organisms of the same species that live together in the same place make up a(n) ____. a. ecosystem b. tissue c. population d. cell e. biosphere

c. population

Changes in pre-mRNA processing and the rate at which mRNAs are degraded are a part of ____. a. transcriptional regulation b. histone modifications c. posttranscriptional regulation d. genomic imprinting e. chromatin remodeling

c. posttranscriptional regulation

Scientists want to determine whether chemical X, a component of fertilizer, is harmful to fish. They treat fish in the laboratory with increasing amounts of the chemical for one week and then measure their viability. When researchers designed this experiment, they wrote "If chemical X is toxic, the fish will begin to look sick and die." This statement is a(n) ____. a. theory b. hypothesis c. prediction d. result e. interpretation

c. prediction

When lactose is present in the medium, RNA polymerase will bind to the ____ of the E. coli lac operon. a. first codon of the lacZ gene b. transcription initiation site c. promoter d. lacI gene e. operator

c. promoter

Chiasmata form during which phase of meiosis? a. telophase I b. prophase II c. prophase I d. metaphase II e. metaphase I

c. prophase I

What is directly responsible for pumping protons out of the mitochondrial matrix? a. cytochrome c and ubiquinone b. protein complexes I and III c. protein complexes I, III, and IV d. protein complexes I, II, III, and IV e. NADH and FADH2

c. protein complexes I, III, and IV

In proteins, structural segments called ____ provide flexibility that allow parts of the protein to bend, fold, or move. a. β polysaccharides b. β sheets c. random coils d. peptide bonds e. α helices

c. random coils

In order for a cell to respond to the signaling molecule epinephrine, it must have ____. a. receptors with an epinephrine binding site on the cytoplasmic side of the plasma membrane b. ion channels c. receptors with an epinephrine binding site on the plasma membrane surface d. a lipid bilayer through which epinephrine can pass e. nuclear membrane receptors

c. receptors with an epinephrine binding site on the plasma membrane surface

Genetic map units represent ____. a. the actual DNA sequence of a gene b. locations of different alleles of a gene c. relative positions of genes with respect to one another d. absolute physical distances between genes e. the chromosome on which a given gene is located

c. relative positions of genes with respect to one another

PCR is ____. a. a reaction in which restriction enzymes cut a gene of interest from the chromosome b. transcription during which only a portion of the cell's DNA is expressed c. repeated DNA replication cycles of a specific region of a DNA molecule d. DNA replication in which DNA polymerase replicates an entire chromosome e. translation during which only some mRNA molecules are translated to make proteins

c. repeated DNA replication cycles of a specific region of a DNA molecule

The nucleoli, found within the nucleus, are the sites of ____ synthesis. a. chromatin b. mRNA c. ribosomal subunit d. gene e. protein

c. ribosomal subunit

Cells that are making large quantities of proteins will have numerous ____. a. centrioles b. chromosomes c. ribosomes d. cilia e. plastids

c. ribosomes

E. coli is propelled by ____. a. a single cilium b. rotating bundles of cilia c. rotating bundles of flagella d. rotating bundles of pili e. a single flagellum

c. rotating bundles of flagella

In which type of microscopy is a beam of electrons used to scan the specimen, followed by the conversion of the excited electrons to a three-dimensional image? a. fluorescence microscopy b. bright field microscopy c. scanning electron microscopy d. confocal laser scanning microscopy e. phase-contrast microscopy

c. scanning electron microscopy

Tight junctions ____. a. allow ions and small molecules to pass between cells b. anchor the cell membrane to the cell wall c. seal the spaces between cells d. allow cells to communicate with each other e. give the cell its shape

c. seal the spaces between cells

The amino acid targets of protein kinases in all GPCR pathways are ____. a. serine and tyrosine b. glycine and tyrosine c. serine and threonine d. glycine and threonine e. serine and glycine

c. serine and threonine

How many transmembrane domains are present in a G-protein-coupled receptor? a. three b. nine c. seven d. one e. five

c. seven

In agarose gel electrophoresis, DNA is visualized by ____. a. staining the gel with an agarose-binding dye so the gel, but not the DNA bands, fluoresces under UV light b. staining the DNA with X-gal so that the DNA bands appear blue c. staining the gel with a DNA-binding dye that fluoresces under UV light d. staining the gel with a DNA-binding dye that fluoresces under natural light e. staining the DNA with a DNA-binging dye that fluoresces under natural light

c. staining the gel with a DNA-binding dye that fluoresces under UV light

The molecule shown above is a(n) ____. a. amino acid b. phospholipid c. steroid d. triglyceride e. polysaccharide http://cnow.apps.ng.cengage.com/ilrn/books/ru2bd04t/MTQA-83611_Images/ch03_image7.JPEG

c. steroid

Some restriction endonucleases cut DNA in such a way that short, single-stranded regions known as ____ ends are created. a. jagged b. tacky c. sticky d. hydrogen-bonding e. blunt

c. sticky

Which structure holds homologous chromosomes tightly together and supports them as they undergo recombination? a. kinetochore b. microtubules c. synaptonemal complex d. spermatozoa e. centromere

c. synaptonemal complex

One of the three internal cell cycle checkpoints occurs during ____ and monitors ____. a. anaphase; the presence of DNA damage b. late S phase; the presence of DNA damage c. the G2/M transition; the presence of DNA damage d. the G2/M transition; mitotic spindle integrity e. the G1/S transition; mitotic spindle integrity

c. the G2/M transition; the presence of DNA damage

In a mature plant cell, ____ may occupy more than 90% of the cell's volume. a. the nucleus b. chloroplasts c. the central vacuole d. rough endoplasmic reticulum e. chromoplasts

c. the central vacuole

What is the proton-motive force? a. the free energy associated with the removal of hydrogen from NADH b. the amount of energy required to protonate a glucose molecule c. the combination of a proton and voltage gradient across the inner mitochondrial membrane d. the force needed to move protons into the inner mitochondrial space e. the synthesis of ATP from a proton gradient

c. the combination of a proton and voltage gradient across the inner mitochondrial membrane

Which part of the ATP synthase is responsible for catalyzing ATP formation? a. the lollipop b. the electrons c. the headpiece d. the stalk e. the basal unit

c. the headpiece

Which component of the PCR reaction is responsible for its specificity? a. the thermocycler b. the four nucleoside triphosphates c. the pair of DNA primers d. DNA polymerase e. the pair of RNA primers

c. the pair of DNA primers

2D chromatography is so named because ____. a. the molecules are separated into a linear arrangement, meaning two dimensions b. there are two steps: labeling with a radioactive marker and separation via chromatography c. the process separates the molecules in two directions, first along the x axis and then along the y axis d. two different solutions are used in the paper chromatography process e. two different types of radioactive markers must be used

c. the process separates the molecules in two directions, first along the x axis and then along the y axis

What is the ultimate source of energy for almost all organisms? a. catabolism of sugars b. ATP c. the sun d. catabolism of sugars, fats, and proteins e. catabolism of fats

c. the sun

The overall process by which information carried by a signaling molecule is translated into changes that occur inside the cell is called signal ____. a. interaction b. digression c. transduction d. induction e. digestion

c. transduction

A plant cell with three sets of chromosomes is ____. a. hexaploid b. tetraploid c. triploid d. diploid e. haploid

c. triploid

Microtubules are assembled from ____. a. myosin b. keratin c. tubulin d. actin e. laminin

c. tubulin

During prophase I of meiosis, each chromosome consists of ____. a. one sister chromatid b. one single-stranded DNA molecule c. two sister chromatids d. one double-stranded DNA molecule e. four sister chromatids

c. two sister chromatids

The two amino acids in the accompanying figure both have side groups (R groups) that are ____. a. uncharged and nonpolar b. acidic and polar c. uncharged and polar d. basic and polar e. acidic and nonpolar http://cnow.apps.ng.cengage.com/ilrn/books/ru2bd04t/MTQA-83611_Images/ch03_image12.JPEG

c. uncharged and polar

Recombination frequency is ____. a. a physical measurement of the distance between two genes on a chromosome b. low if crossovers are common between two genes c. used to create linkage maps d. measured in centigrams e. high if two genes are linked

c. used to create linkage maps

See the provided genetic code table. A change in a single base pair could cause which missense mutation? a. glycine to proline b. glutamic acid to threonine c. valine to methionine d. glutamic acid to methionine e. threonine to glutamine

c. valine to methionine

Most pH buffers are ____. a. strong bases b. strong acids or strong bases c. weak acids or weak bases d. strong acids e. weak acids

c. weak acids or weak bases

What is directly sequenced in RNA-seq? a. transcripts b. protein c. DNA d. cDNA e. RNA

cDNA

When insect populations exposed to insecticides develop resistance to these toxic chemicals over time, it is an example of natural selection ____.

changing nonmorphological traits

The comparison of homologous traits in living and extinct organisms is an example of ____.

comparative morphology

The fossil record documents ____, providing clear evidence of ongoing change in biological lineages

continuity in morphological characteristics

The enzymes responsible for hydrolyzing glucose into glyceraldehyde-3-phosphate (G3P) are found in which part of the cell? a. mitochondria b. rough ER c. cell membrane d. nucleus e. cytosol

cytosol

The free energy of ATP hydrolysis is -31.0 kJ/mol. The free energy of glucose phosphorylation by hexokinase is +14.3 kJ/mol. These two reactions are coupled to allow them to proceed spontaneously. What is the overall free energy associated with this coupled reaction? a. 16.7 kJ/mol b. -45.3 kJ/mol c. -31 kJ/mol d. -16.7 kJ/mol e. 45.3 kJ/mol

d. -16.7 kJ/mol

The genome of an organism contains 14% guanine; therefore, its genome also contains ____% thymine and ____% cytosine. a. 14; 36 b. 86; 14 c. 14; 86 d. 36; 14 e. 36; 36

d. 36; 14

Arrange the events in the pathway activated by G-protein-coupled receptors (GPCRs) in the correct order. 1. Activation of effector 2. Activation of protein kinases 3. Receptor binds first messenger 4. Production of second messenger 5. Activation of G protein a. 3→1→5→4→2 b. 1→3→5→2→4 c. 3→5→2→4→1 d. 3→5→1→4→2 e. 2→3→5→4→1

d. 3→5→1→4→2

In a frog in which the diploid number of chromosomes per cell is 24, what is the total number of chromatids present during prophase I? a. 6 b. 12 c. 4 d. 48 e. 24

d. 48

During translation, mRNA is read in the ____ direction and the polypeptide is assembled from the ____. a. 5→3→; C-terminal end to the N-terminal end b. 3→5→; N-terminal end to the C-terminal end c. 5→5→; N-terminal end to the C-terminal end d. 5→3→; N-terminal end to the C-terminal end e. 3→5→; C-terminal end to the N-terminal end

d. 5→3→; N-terminal end to the C-terminal end

Which molecule stimulates phosphofructokinase to increase the flow of intermediates through glycolysis? a. FADH2 b. NADH c. ATP d. AMP e. acetyl CoA

d. AMP

Which products of the light reactions are used in the Calvin cycle? a. ADP and NADP+ b. CO2 and RuBP c. electrons and photons d. ATP and NADPH e. water, O2, and ATP

d. ATP and NADPH

What is the relationship between operons and transcription units? a. An operon is composed of multiple transcription units. b. A transcription unit is composed of multiple operons. c. A transcription unit consists of an operon plus associated regulatory DNA sequences. d. An operon consists of a transcription unit plus associated regulatory DNA sequences. e. They are synonymous terms.

d. An operon consists of a transcription unit plus associated regulatory DNA sequences.

Answer the question using the accompanying graph. Which portion of the graph shows the free energy of the reaction? a. A b. W + X c. Y + Z d. C e. B

d. C

As part of an experiment, researchers grew several different types of cells in the presence of radioactive iodine. After some time had passed, the cells were washed, and the levels of iodine inside the cell was determined. What is the most plausible explanation for why some cells had higher levels of radioactivity after treatment than others? a. Cells that had high radioactivity levels after treatment lack iodine transporters. b. Cells that had high radioactivity levels after treatment lack lysosomes. c. Cells that had high radioactivity levels after treatment have a mutation in genes encoding iodine transporter proteins. d. Cells that had high radioactivity levels after treatment contain iodine transporters. e. Cells that had high radioactivity levels after treatment lack clathrin.

d. Cells that had high radioactivity levels after treatment contain iodine transporters.

Mendel studied what he called characters and traits. What is the relationship between these terms? a. Characters are passed to the next generation; traits are never passed to the next generation. b. Characters are the unknown packages transferred to the next generation; traits result from this transfer. c. Traits are heritable characteristics; characters are variations of traits. d. Characters are heritable characteristics; traits are variations of characters. e. Characters and traits are synonymous in Mendel's writings.

d. Characters are heritable characteristics; traits are variations of characters.

What is the difference between cofactors and coenzymes? a. Cofactors can be inorganic or organic, but coenzymes are always inorganic. b. Cofactors are always vitamins, but coenzymes are always ions. c. Cofactors help with essential metabolic reactions, but coenzymes assist with nonessential metabolic reactions. d. Cofactors can be inorganic or organic, but coenzymes are organic cofactors. e. Cofactors are not necessary for enzyme function, but coenzymes are.

d. Cofactors can be inorganic or organic, but coenzymes are organic cofactors.

The transforming principle described by Griffith in his work with Streptococcus pneumoniae is ____. a. a phospholipid b. RNA c. protein d. DNA e. a polysaccharide capsule

d. DNA

Chromatin consists of ____. a. DNA only b. RNA and protein c. DNA and RNA d. DNA and protein e. DNA, RNA, and protein

d. DNA and protein

In the Meselson-Stahl experiment, bacterial DNA was labeled completely with heavy nitrogen (15N) and then grown in the presence of light nitrogen (14N). When only mixed DNA was observed after ONE generation of growth in 14N, what was the conclusion? a. DNA replication is conservative. b. DNA replication is semiconservative. c. DNA replication is either semiconservative or conservative. d. DNA replication is either semiconservative or dispersive. e. DNA replication is dispersive.

d. DNA replication is either semiconservative or dispersive.

DNA transposons move using a(n) ____ intermediate while retrotransposons move using a(n) ____ intermediate. a. DNA; snRNP b. RNA; protein c. DNA; protein d. DNA; RNA e. RNA; DNA

d. DNA; RNA

Which statement is a part of the first law of thermodynamics? a. Energy cannot be transformed. b. The entropy of the universe is decreasing. c. Potential energy is the energy of motion. d. Energy can be neither created nor destroyed. e. The entropy of the universe is constant.

d. Energy can be neither created nor destroyed.

What is the source of electrons for carbon fixation in plants? a. C6H12O6 b. O2 c. H+ d. H2O e. CO2

d. H2O

P700 is located in photosystem(s) ____ and is comprised of chlorophyll ____. a. I; b b. II; b c. II; a d. I; a e. I and II; a

d. I; a

How do the haploid and diploid phases of the plant life cycle differ from those of the animal life cycle? a. In plants, the diploid phase dominates the life cycle, while in animals the haploid phase dominates the life cycle. b. In plants, meiosis occurs during the haploid phase, while in animals meiosis occurs during the diploid phase. c. In plants, mitosis occurs only during the haploid phase while in animals mitosis occurs only during the diploid phase. d. In plants, mitosis occurs during both the haploid and diploid phases, while in animals mitosis occurs only during the diploid phase. e. In plants, mitosis occurs only during the diploid phase, while in animals mitosis occurs only during the haploid phase.

d. In plants, mitosis occurs during both the haploid and diploid phases, while in animals mitosis occurs only during the diploid phase.

Free radicals, highly reactive species with unpaired electrons that damage molecules and cells, can contribute to aging. Coenzyme Q (also known as ubiquinone or CoQ) is often found in lotions and moisturizers. Given what you know about the role of CoQ in cellular respiration, why would it be added to these products? a. Removing free radicals decreases the rate of metabolism and slows growth of skin cells. b. It recruits free radicals to help increase the rate of glycolysis in skin cells. c. It drives the spontaneous death of older skin cells that have accumulated too many free radicals. d. It absorbs free radicals that can cause damage to skin cells. e. It allows for the regeneration of new skin cells.

d. It absorbs free radicals that can cause damage to skin cells.

What happens to an enzyme after it has catalyzed a reaction? a. It is inactivated by dephosphorylation. b. It is sent to the proteasome for degradation. c. It is inactivated by phosphorylation. d. It returns to its original state. e. It releases the cofactor to get a new one ready for catalysis.

d. It returns to its original state.

What is a difference between human male and female genomes? a. Males have 22 pairs of autosomal chromosomes; females have 21 pairs of autosomal chromosomes. b. Males have 23 pairs of chromosomes plus 1 Y chromosome; females have 23 pairs of chromosomes. c. Males have an X chromosome; females do not. d. Males have 24 different chromosomes; females have 23 different chromosomes e. Males have 46 chromosomes; females have 45.

d. Males have 24 different chromosomes; females have 23 different chromosomes

In early experiments to understand the control of the cell cycle, researchers fused HeLa cells that were at different stages of the cell cycle. What did the results of these experiments suggest? a. Microtubules play an essential role in the progression of the cell cycle. b. The cell cycle has three checkpoints through which the cell must pass in order to progress through to mitosis. c. The concentrations of cyclins fluctuate throughout the cell cycle. d. Molecules in the cytoplasm control the progression of the cell cycle. e. The concentrations of cyclin dependent kinases (Cdks) fluctuate throughout the cell cycle.

d. Molecules in the cytoplasm control the progression of the cell cycle.

Cellular respiration is the process by which ____ and ____ are converted to water and carbon dioxide during the synthesis of ATP. a. CO2; fats b. ATP; O2 c. O2; CO2 d. O2; glucose e. CO2; glucose

d. O2; glucose

A gene being transcribed uses transcription factors to recruit RNA polymerase II to the DNA at the promoter region. After the polymerase is recruited, transcription elongation occurs, and nucleotides are added to the transcript in the 5' → 3' direction. How do you know that the gene being transcribed is not a prokaryotic gene? a. Prokaryotes do not have promoters. b. In prokaryotes, nucleotides are added to the transcript in the 3' → 5' direction. c. In prokaryotes, the promoter comes after the transcription unit. d. Prokaryotes do not use transcription factors to recruit RNA polymerase to the DNA. e. Prokaryotes use ribosomes rather than RNA polymerase to transcribe genes.

d. Prokaryotes do not use transcription factors to recruit RNA polymerase to the DNA.

Which notation represents a monohybrid cross? a. rr × RR b. Rr × rr c. RrMM × Rrmm d. Rr × Rr e. RRMM × rrmm

d. Rr × Rr

In order to elucidate the Calvin cycle, Calvin and his colleagues used two-dimensional paper chromatography to analyze the presence of different molecules under different conditions. What did they conclude from the accumulation of RuBP when CO2 levels were low? a. RuBP only reacts with CO2 when concentrations of ATP are low. b. CO2 serves as a noncompetitive inhibitor of rubisco. c. RuBP is the last substrate to react in the Calvin cycle. d. RuBP is the first substrate to react with CO2. e. RuBP only reacts with CO2 in the sunlight.

d. RuBP is the first substrate to react with CO2.

How does energy coupling allow chemical reactions that are not spontaneous to proceed? a. The energy from the endergonic reaction is transferred to the substrate to stabilize it. b. The energy from both reactions increases the total free energy. c. The energy from the endergonic reaction is transferred to the enzyme to stabilize the transition state. d. The energy from the exergonic reaction is transferred to the substrate to destabilize it. e. The energy from the exergonic reaction is transferred to the substrate to stabilize it.

d. The energy from the exergonic reaction is transferred to the substrate to destabilize it.

How does sickle-cell disease cause death? a. The mutant hemoglobin polypeptide cannot bind O2 due to a change in three amino acids. b. More cells assume the sickle shape as oxygen concentration in the tissues increases. c. The malformed blood cells have a higher affinity for CO2 than for oxygen. d. The malformed red blood cells can block capillaries. e. The malformed red blood cells cannot transport oxygen.

d. The malformed red blood cells can block capillaries.

Which statement correctly summarizes the two phases of photosynthesis? a. The light-dependent reactions produce water as a byproduct; the light-independent reactions produce carbon dioxide as a waste product. b. The products of the light-dependent reactions are ADP, NADP+, and O2; the products of the light-independent reactions are ATP, NADPH, and sugar. c. The light-dependent reactions occur in the cytosol; the light-independent reactions occur in the stroma. d. The products of the light-dependent reactions are ATP, NADPH, and O2; the products of the light-independent reactions are ADP, NADP+, and sugar. e. The light-dependent reactions occur only during the daylight hours; the light-independent reactions occur only when it is dark.

d. The products of the light-dependent reactions are ATP, NADPH, and O2; the products of the light-independent reactions are ADP, NADP+, and sugar.

Pure water has a pH of 7.0, therefore, ____. a. [OH-] = 0 b. [H+] < [OH-] c. [H+] = 0 d. [H+] = [OH-] e. [H+] > [OH-]

d. [H+] = [OH-]

Identical twins can result from ____. a. a lack of chromosomal separation during meiosis resulting in gametes that are diploid b. the fusion of two sets of identical gametes c. a mechanism that is not understood d. a division of a zygote into two separate cells that develop into two separate embryos e. the fusion of two paternal gametes with a single maternal gamete that then divides

d. a division of a zygote into two separate cells that develop into two separate embryos

Oxidative phosphorylation is the process by which ____. a. ATP is made using high energy intermediates of cellular respiration b. NAD+ is regenerated to allow glycolysis to continue c. high-energy NADH is made to supply the cell with its needed energy d. a final electron acceptor is used indirectly to facilitate the production of ATP e. specific enzymes are regulated to control cellular respiration

d. a final electron acceptor is used indirectly to facilitate the production of ATP

Compared to the mitochondrial intermembrane space, the mitochondrial matrix could be described as having ____ pH and _____ pyruvate concentration. a. a higher; higher b. a lower; lower c. the same; the same d. a higher; lower e. a lower; higher

d. a higher; lower

Substance A is secreted by the liver, travels through the circulatory system bound to a carrier protein, and causes a change in gene expression in its target cell. Substance A is therefore a ligand for ____. a. a G-protein-coupled receptor b. a receptor tyrosine kinase c. guanylyl cyclase d. a steroid hormone receptor e. a ligand-gated ion channel

d. a steroid hormone receptor

Methylation regulates transcription by ____. a. interfering with the chromatin remodeling process b. adding a methyl group to cytosine residues on RNA polymerase II c. adding a methyl group to cysteine bases of DNA d. adding a methyl group to cytosine bases of DNA e. adding a methyl group to cysteine residues on RNA polymerase II

d. adding a methyl group to cytosine bases of DNA

Which bases are found in RNA? a. adenine, thymine, and cytosine only b. adenine, thymine, guanine, and cytosine c. adenine, uracil, and cytosine only d. adenine, uracil, guanine, and cytosine e. adenine and uracil only

d. adenine, uracil, guanine, and cytosine

Which meiotic phase is matched with the mitotic phase it most closely represents? a. anaphase I and anaphase b. metaphase I and metaphase c. metaphase II and prophase d. anaphase II and anaphase e. interkinesis and telophase

d. anaphase II and anaphase

Which plant cell structure is comprised of approximately 300 chlorophyll molecules and about 40 carotenoid pigments, organized together to optimize the capture of light energy? a. chlorophyll b. reaction center c. stomata d. antenna complex e. cytochrome complex

d. antenna complex

Which element is likely to be chemically unreactive? a. carbon (4 valence electrons) b. potassium (1 valence electron) c. calcium (2 valence electrons) d. argon (8 valence electrons) e. chlorine (7 valence electrons)

d. argon (8 valence electrons)

To reach the mitochondrial matrix, protons travel through a channel made by the ____ of ATP synthase. a. lollipop b. three catalytic sites c. stalk d. basal unit e. headpiece

d. basal unit

What is a function of prokaryotic common pili? a. energy production b. transfer of DNA c. lipid synthesis d. biofilm formation e. protein polymerization

d. biofilm formation

The movement of water across a membrane from an area of high to low water concentration is an example of ____. a. active transport only b. osmosis only c. both osmosis and active transport d. both diffusion and osmosis e. endocytosis only

d. both diffusion and osmosis

The movement of water across a membrane from an area of lower solute concentration to a region of higher solute concentration is called ____. a. osmosis only b. active transport only c. endocytosis only d. both diffusion and osmosis e. both osmosis and active transport

d. both diffusion and osmosis

Where can you find ATP synthase in a plant cell? a. in the thylakoid membrane only b. in the mitochondrial inner membrane only c. only in the nucleus d. both the thylakoid and inner mitochondrial membranes e. embedded in the plasma membrane

d. both the thylakoid and inner mitochondrial membranes

How does the cell overcome inhibition from irreversible inhibitors? a. by phosphorylating the enzyme, altering the enzyme's conformation to dislodge the inhibitor b. by upregulating the expression of other enzymes with similar catalytic functions c. by altering the cellular pH, which will decrease the bonding between the enzyme and the inhibitor d. by degrading the enzyme-inhibitor complex and generating new enzyme e. by binding a second inhibitor, which forces the enzyme's conformation to dislodge the first inhibitor

d. by degrading the enzyme-inhibitor complex and generating new enzyme

Where does the energy for ATP synthesis come from? a. anabolism of simple molecules into complex molecules b. anabolism of complex molecules directly into ATP c. catabolism of simple molecules into complex molecules d. catabolism of complex molecules into simpler molecules e. anabolism of complex molecules into simpler molecules

d. catabolism of complex molecules into simpler molecules

Enzymes ____. a. change the direction of a reaction b. change the free energy of a reaction c. are used up in a reaction d. change the rate of a reaction e. are present in concentrations approaching their substrates' concentrations

d. change the rate of a reaction

Which polysaccharide is a chain of glucose units that are modified by having nitrogen-containing groups, is the main structural fiber in the external skeletons of arthropods, and also a structural material in the cell walls of fungi? a. amylopectin b. cellulose c. amylose d. chitin e. glycogen

d. chitin

Grana and thylakoids are structural components found in ____. a. nucleoli b. chromoplasts c. ribosomes d. chloroplasts e. mitochondria

d. chloroplasts

Where does photosynthesis occur in plant cells? a. cytosol b. plasma membrane c. mitochondria d. chloroplasts e. Golgi bodies

d. chloroplasts

Which molecules coat the inside of the cytosolic membrane to help form endocytic vesicles? a. aquaporins b. antibodies c. cholesterols d. clathrins e. microtubules

d. clathrins

Which type of microscopy utilizes lasers that scan across a fluorescently stained specimen and a computer that focuses the light to give sharp three-dimensional images? a. phase-contrast microscopy b. bright field microscopy c. scanning electron microscopy d. confocal laser scanning microscopy e. fluorescence microscopy

d. confocal laser scanning microscopy

One function of the 3' UTR (untranslated region) of mRNA is to ____. a. help activators bind to the enhancer region b. base pair with the translated region of the transcript to mark it for degradation c. bind RNA polymerase to initiate transcription d. control the half-life of mRNA e. bind ribosomes to initiate translation

d. control the half-life of mRNA

In humans, a deletion from chromosome 5 typically leads to severe mental retardation and a malformed larynx; this disorder is known as ____. a. Triple-X syndrome b. Turner syndrome c. Down syndrome d. cri-du-chat e. Klinefelter syndrome

d. cri-du-chat

For most eukaryotic genes, translation begins in the____. a. mitochondria b. nucleolus c. Golgi apparatus d. cytosol e. nucleus

d. cytosol

The genetic material of all living organisms is ____. a. polypeptide b. ribonucleic acid c. protein d. deoxyribonucleic acid e. glycoprotein

d. deoxyribonucleic acid

Which molecule is a common second messenger? a. cATP b. cGTP c. Ras d. diacylglycerol e. PIP2

d. diacylglycerol

A gene encoding a subunit of hemoglobin in humans is found to be homologous to a gene in chimpanzees. The homologous gene in chimpanzees likely _____. a. encodes a respiratory enzyme b. is a pseudogene c. is a regulatory sequence d. encodes the same hemoglobin subunit e. is inactive because it is in a different species

d. encodes the same hemoglobin subunit

Once transduction of a signal is complete, the receptor and its bound signaling molecule are removed from the cell surface by ____. a. exocytosis b. pinocytosis c. hydrolysis d. endocytosis e. diffusion

d. endocytosis

Which two factors determine whether a reaction is spontaneous? a. entropy and activation energy b. activation energy and energy coupling c. activation energy and enthalpy d. enthalpy and entropy e. free energy and activation energy

d. enthalpy and entropy

Answer the question by using the accompanying graph. If all three enzymes catalyze the same reaction and your experimental conditions require a pH of 8, which enzyme would you choose? a. enzyme 1 b. both enzymes 2 and 3 c. either enzyme 2 or 3 d. enzyme 3 e. enzyme 2

d. enzyme 3

Loosely packed regions of DNA associated with histones are called ____. a. chromosomes b. 30-nm chromatin fibers c. nucleosomes d. euchromatin e. heterochromatin

d. euchromatin

Nucleosomes are best described as ____. a. eukaryotic DNA associated with nonhistone proteins b. prokaryotic DNA associated with nonhistone proteins c. prokaryotic DNA associated with histone proteins d. eukaryotic DNA associated with histone proteins e. associated histone and nonhistone proteins

d. eukaryotic DNA associated with histone proteins

Consider the equilibrium established in the carbonic acid-bicarbonate buffer system, which maintains pH balance in mammalian blood: H2CO3 → HCO3- + H+ During hypoventilation, breathing rate decreases, and therefore elimination of CO2 during exhalation decreases. How is optimal blood pH maintained when acid levels increase in our blood from hypoventilating? a. excess H+ from the acid react with HCO3- to increase pH level b. excess H+ from the acid react with H2CO3 to decrease pH level c. excess H+ from the acid react with H2CO3 to maintain pH level d. excess H+ from the acid react with HCO3- to maintain pH level e. excess H+ from the acid react with H2CO3 to increase pH level

d. excess H+ from the acid react with HCO3- to maintain pH level

Polar and charged molecules typically cross the cell membrane by way of ____. a. simple diffusion b. filtration c. osmosis d. facilitated diffusion e. active transport

d. facilitated diffusion

Nondisjunction refers to the ____. a. failure of sister chromatids to pair during mitosis b. failure of homologous pairs to separate during mitosis c. failure of sister chromatids to separate during mitosis d. failure of homologous pairs or sister chromatids to separate during meiosis e. improper pairing of nonhomologous chromosomes during meiosis

d. failure of homologous pairs or sister chromatids to separate during meiosis

When a molecule is reduced, it ____. a. stores electrons b. burns energy c. loses energy d. gains electrons e. loses electrons

d. gains electrons

The coordinated beating of the heart is accomplished in part by the presence of ____ in heart muscle tissue that allows for communication between the cells. a. anchoring junctions b. desmosomes c. adherens junctions d. gap junctions e. tight junctions

d. gap junctions

Through a sequence similarity search, a researcher identifies a gene whose predicted protein product has a putative function of a photosynthesis-enhancing enzyme. Which experimental method could be performed to verify this function? a. an assay measuring photosynthetic productivity b. DNA microarray c. PCR d. gene knockout e. identification of signature genes

d. gene knockout

Which process exchanges alleles between homologous chromosomes? a. asexual reproduction b. mitosis c. anaphase d. genetic recombination e. independent assortment

d. genetic recombination

The characterization of whole genomes, including their structures (sequences), functions, and evolution is called ____. a. genetic engineering b. biotechnology c. genetic engineering d. genomics e. bioinformatics

d. genomics

In many animals, this polysaccharide is found in large quantities in liver and muscle cells. It is highly branched, with many α (1-4) and α (1-6) linkages. a. amylose b. amylopectin c. chitin d. glycogen e. cellulose

d. glycogen

The linkage commonly found between subunits in a chain of monosaccharides is called a ____ bond. a. peptide b. disulfide c. phosphodiester d. glycosidic e. hydrogen

d. glycosidic

In humans, males are the ____ sex, and females are the ____ sex. a. dominant, recessive b. autosomal, maternal c. recessive, dominant d. heterogametic, homogametic e. homogametic, heterogametic

d. heterogametic, homogametic

In the case of complete dominance, if a plant has a ____ genotype for a particular trait, its phenotype will have the ____ trait. a. homozygous dominant; recessive b. heterozygous; recessive c. heterozygous; recessive d. heterozygous; dominant e. homozygous recessive; dominant

d. heterozygous; dominant

Maintaining your body's internal temperature within a narrow tolerable range is one example of ____. a. hydrolysis b. compensation c. perspiration d. homeostasis e. respiration

d. homeostasis

RNA-seq (whole-transcriptome sequencing) _____. a. is being replaced by DNA microarrays in transcriptomics b. is the most common method used to identify certain cancer genes c. is a new hybridization technique used in transcriptomics d. identifies and quantifies RNA transcripts in a sample e. can only identify 100 sequences at a time

d. identifies and quantifies RNA transcripts in a sample

Which adaptation to the plasma membrane allows mammals to hibernate in subzero temperatures without their plasma membranes freezing? a. increase in protein content only b. increase in the number of double covalent bonds in phospholipids c. increase in both cholesterol and protein content d. increase in both cholesterol and double covalent bonds in phospholipids e. increase in cholesterol content only

d. increase in both cholesterol and double covalent bonds in phospholipids

In competitive inhibition, the ____. a. inhibitor binds to the enzyme at a site other than its active site b. substrate and cofactors compete for the active site c. products bind to a site other than the active site of the enzyme and block enzyme activity indirectly d. inhibitor binds to and directly blocks the active site of the enzyme e. products block the active site of the enzyme

d. inhibitor binds to and directly blocks the active site of the enzyme

Which class of proteins is embedded in the phospholipid bilayer? a. peripheral proteins b. protein hormones c. transcription factor proteins d. integral proteins e. cytoskeletal proteins

d. integral proteins

In humans, the majority of a transcription unit is composed of ____. a. exons b. regulatory elements c. start codons d. introns e. promoter regions

d. introns

Radioactive ____ is commonly used to treat patients with dangerously overactive thyroid glands. a. thallium b. cobalt c. carbon d. iodine e. radium

d. iodine

Taq polymerase is commonly used in PCR reactions because it ____. a. keeps the primers from annealing to the DNA b. helps the primers anneal to the correct DNA sequence c. is more efficient at replicating DNA than other DNA polymerases d. is a heat-stable DNA polymerase e. makes fewer DNA replication errors than other DNA polymerases

d. is a heat-stable DNA polymerase

A network of protein filaments called ____ lines and reinforces the inner surface of the nuclear envelope in animal cells. a. chromatins b. lamellae c. tubulins d. lamins e. actins

d. lamins

The site on a chromosome where a gene is located is called its ____. a. marker b. character c. trait d. locus e. homologue

d. locus

Pairs of alleles are found at a particular ____ on a pair of ____. a. base; homozygous genes b. nucleotide; genes c. sister chromatid; homologous chromosomes d. locus; homologous chromosomes e. gene; gametes

d. locus; homologous chromosomes

When the human genome was sequenced, we learned that there are fewer than expected protein coding genes (approximately 20,000). Yet, the total number of proteins produced in humans approaches 100,000. What accounts for this discrepancy in numbers? a. We have not yet fully sequenced the human genome. b. We have not yet identified all of the open reading frames in the human genome. c. There has been a gross over-estimation of the number of proteins produced in humans. d. mRNA processing mechanisms allow multiple proteins to be produced from a single DNA sequence. e. Some noncoding DNA sequences encode proteins.

d. mRNA processing mechanisms allow multiple proteins to be produced from a single DNA sequence.

Cancer cells ____. a. cannot replicate their DNA b. have circular chromosomes c. have longer telomeres than normal cells d. maintain telomerase function e. eventually die due to shortening chromosomes

d. maintain telomerase function

Long noncoding RNAs ____. a. are transcribed by RNA polymerase I rather than by RNA polymerase II b. are missing a 5' cap and 3' poly(A) tail c. encode large proteins d. may regulate the expression of protein-coding genes e. do not have their introns removed

d. may regulate the expression of protein-coding genes

Which organelles contain enzymes involved in reactions linking major biochemical pathways, including the breakdown of fats, some amino acids, and alcohols? a. ribosomes b. cisternae c. cristae d. microbodies e. lysosomes

d. microbodies

The separation of duplicated chromosomes into two new nuclei is known as ____. a. cytokinesis b. fertilization c. meiosis d. mitosis e. binary fission

d. mitosis

In humans, there are three genes encoding different nitric oxide synthase enzymes. These three genes form a ____. a. replicate gene family b. gene grouping c. multi-enzyme family d. multigene family e. multigene locus

d. multigene family

When the isotope 14C undergoes radioactive decay, a neutron splits into an electron and a proton, with ejection of the electron. This decay produces an atom of ____. a. oxygen b. hydrogen c. iron d. nitrogen e. carbon

d. nitrogen

Substitution of one base pair for another in a coding region of a gene can result in a ____ mutation where a codon specifying an amino acid is changed to a stop codon. a. silent b. chromosomal c. frameshift d. nonsense e. missense

d. nonsense

Where is the trp repressor gene located? a. just upstream of the trp operon b. directly adjacent to the promoter region of the trp operon c. just downstream of the trp operon d. on a region of the chromosome distant from the trp operon e. adjacent to the lac repressor gene

d. on a region of the chromosome distant from the trp operon

You have recently identified a molecule you believe to be a signaling molecule associated with signal transduction. All you know about this molecule is that it is hydrophilic; therefore, you expect it to interact with a receptor ____. a. in the nucleus of the cell b. associated with the endoplasmic reticulum c. within the cytoplasm of the cell d. on the cell surface e. on the cytoplasmic surface of the plasma membrane

d. on the cell surface

For most multicellular eukaryotes, including humans, mitochondria are inherited ____. a. randomly from either the father or the mother b. from both the father and the mother c. from the mother for female offspring and from the father for male offspring d. only from the mother e. only from the father

d. only from the mother

Genes that are closely related evolutionarily, have the same function, and are present in the genomes of two or more different organisms are called _____. a. genologs b. paralogs c. metalogs d. orthologs e. heterologs

d. orthologs

To experimentally determine the function of an annotated gene, a researcher may _____. a. look for similar gene sequences of known function b. find a pseudogene for the gene c. determine the amino acid sequence d. perform a gene knockout e. examine the putative protein structure

d. perform a gene knockout

Restriction endonucleases break ____ bonds. a. ester b. hydrogen c. glycosidic d. phosphodiester e. peptide

d. phosphodiester

In the light-dependent reactions of photosynthesis, an excited electron from photosystem II is passed along an electron transport chain to ____. a. NADH b. water c. NAD+ d. photosystem I e. oxygen

d. photosystem I

Experiments with mouse cells indicate that long noncoding RNAs ____. a. are not expressed in embryonic stem cells b. are transcription factors that promote cardiac cell differentiation c. are only expressed after cardiac cells have differentiated d. play a role in cardiac cell differentiation e. block cardiac cell development

d. play a role in cardiac cell differentiation

A short RNA chain is synthesized as the first nucleotides in a new DNA strand by the enzyme ____ to provide a ____ for DNA elongation. a. topoisomerase; 3' hydroxyl group b. DNA polymerase; 5' phosphate group c. DNA polymerase; 3' hydroxyl group d. primase; 3' hydroxyl group e. primase; 5' hydroxyl group

d. primase; 3' hydroxyl group

Chaperonins assist with ____. a. assembly of DNA strands b. forming the DNA double helix c. polysaccharide synthesis d. protein folding e. proteins synthesis

d. protein folding

The final product of glycolysis is ____. a. glucose b. fructose c. carbon dioxide d. pyruvate e. glyceraldehyde-3-phosphate

d. pyruvate

A hydrogen bond between the amino acid side groups (R groups) of two different polypeptide chains in a multichain protein would be considered part of the ____ structure of the protein. a. primary b. secondary c. linear d. quaternary e. tertiary

d. quaternary

The insulin receptor is an example of a(n) ____. a. G-protein-coupled receptor b. hydrophobic receptor c. ion channel receptor d. receptor tyrosine kinase e. hormone receptor

d. receptor tyrosine kinase

Living systems have the capacity to detect environmental changes and compensate for them through controlled responses. This is possible because living systems have ____. a. nerves b. hormones c. sensitivity d. receptors e. reflexes

d. receptors

Genetic variability in meiosis results from ____. a. random joining of male and female gametes only b. recombination between sister chromatids and homologous chromosomes c. independent assortment of chromosomes only d. recombination of homologous chromosomes, independent assortment of chromosomes, and random joining of male and female gametes e. recombination of homologous chromosomes only

d. recombination of homologous chromosomes, independent assortment of chromosomes, and random joining of male and female gametes

What type of chemical reaction must occur for electrons to flow from one molecule to the next and supply the energy for metabolism? a. acid/base b. phosphorylation c. exothermic d. reduction/oxidation e. trimolecular

d. reduction/oxidation

What is the purpose of the third phase of the Calvin cycle? a. oxidation of NADPH b. reduction of NADPH c. carbon fixation d. regeneration of RuBP e. generation of ATP

d. regeneration of RuBP

Many signal transduction pathways utilize second messengers to ____. a. relay a signal from the inside of the cell to the outside b. relay a signal from the outside of the cell to the inside c. decrease the message once the signaling molecules have left the receptor d. relay the message from the inner surface of the plasma membrane throughout the cytoplasm e. transport a signal through the lipid bilayer of the plasma membrane

d. relay the message from the inner surface of the plasma membrane throughout the cytoplasm

The cap on an mRNA transcript is the site where ____. a. translation is terminated b. the start codon is located c. the mRNA is protected from attack by RNA-digesting enzymes d. ribosomes attach at the start of translation e. the stop codon is covered until needed

d. ribosomes attach at the start of translation

Which molecules most easily diffuse across a cell membrane? a. large, polar b. ionic c. large, hydrophobic d. small, hydrophobic e. large, hydrophilic

d. small, hydrophobic

By itself, independent assortment of chromosomes increases the likelihood that individual daughter cells have ____. a. only paternal chromosomes b. chromosomes containing genes from both paternal and maternal chromosomes c. different numbers of chromosomes d. some paternal chromosomes and some maternal chromosomes e. only maternal chromosomes

d. some paternal chromosomes and some maternal chromosomes

When molecules are referred to as D- or L- (for example D-forms of sugars and L-forms of amino acids), the D- and L- designations refer to the specific ____. a. secondary structure b. structural isomer c. functional group d. stereoisomer e. covalent bond

d. stereoisomer

Adding nucleotides onto a growing DNA strand during DNA replication in cells occurs in ____. a. the 5' → 3' direction for the leading strand and the 3' → 5' direction on the lagging strand b. the 3' → 5' direction for the leading strand and the 5' → 3' direction on the lagging strand c. the 3' → 5' direction only d. the 5' → 3' direction only e. either the 5' → 3' direction or the 3' → 5' direction on both strands, depending on where replication begins

d. the 5' → 3' direction only

Which system is considered a closed system? a. a human b. a propane furnace c. a gas-powered automobile d. the Earth e. a single-celled organism

d. the Earth

A typical eukaryotic cell that has an abundant supply of glucose and O2 will generate a proton gradient in its mitochondria by ____ that is used primarily for ____. a. fermentation; NAD reduction b. the electron transport chain; substrate-level phosphorylation c. chemiosmosis; substrate-level phosphorylation d. the electron transport chain; chemiosmosis e. glycolysis; production of CO2

d. the electron transport chain; chemiosmosis

Which element of a dideoxy sequencing reaction allows for visualization of the DNA sequence? a. DNA primer b. DNA polymerase c. the mixture of the four deoxyribonucleotides d. the mixture of the four dideoxyribonucleotides, each with a different fluorescent label e. DNA ligase

d. the mixture of the four dideoxyribonucleotides, each with a different fluorescent label

A key difference between eukaryotic and prokaryotic genomes is ____. a. the regulation of the cell cycle by eukaryotes which is not observed in prokaryotes b. the lack of gene expression controls in prokaryotes c. the physical separation of transcription and translation in prokaryotes compared to the lack of separation of these processes in eukaryotes d. the physical arrangement of genes on the chromosome(s) e. simultaneous transcription and translation in eukaryotes vs. sequential transcription and translation in prokaryotes

d. the physical arrangement of genes on the chromosome(s)

Organisms must constantly bring in certain molecules and ions while keeping others out. This function is accomplished by ____. a. lysosomes b. the Golgi complex c. the nucleus d. the plasma membrane e. vesicles

d. the plasma membrane

If an enzyme is saturated, ____. a. the reaction is at equilibrium b. it cannot continue to catalyze the reaction c. the rate of the reaction will slow and the reaction will stop d. the reaction is being catalyzed at the maximum rate e. it recruits more reactants

d. the reaction is being catalyzed at the maximum rate

Researchers have determined that the growth of hormone-responsive breast cancer cells depends upon ____. a. the ability of ERβ to stimulate cancer cell growth b. the ability of ERα to inhibit cancer cell growth c. whether DNA binding sites exists for ERα, but not ERβ d. the relative concentrations of ERα and ERβ in the tumor cells e. the relative concentrations of estrogen and testosterone in breast tissue

d. the relative concentrations of ERα and ERβ in the tumor cells

What is an open reading frame (ORF)? a. the sequence between and including a start codon and an stop codon, minus the introns b. a protein coding sequence plus associated regulatory sequences c. the sequence between and including a start codon and an stop codon, minus the exons d. the sequence between and including a start codon and an stop codon e. the sequence between a start codon and stop codon in prokaryotes only

d. the sequence between and including a start codon and an stop codon

What is the purpose of cyclic electron flow? a. to protect the cell when CO2 is unavailable and the Calvin cycle is not operating b. to increase the net production of ATP in times when CO2 is unavailable c. to prevent the loss of light energy when the ATP production pathway is saturated d. to prevent the formation of NADPH and excessive reactive oxygen species e. to ensure that all of the energy harvested by the sun is converted into ATP

d. to prevent the formation of NADPH and excessive reactive oxygen species

The genes in an operon are ____. a. each transcribed into individual mRNAs b. transcribed as a single mRNA in prokaryotes, but as individual mRNAs in eukaryotes c. controlled by separate promoters d. transcribed into a single mRNA transcript e. located at different chromosomal loci

d. transcribed into a single mRNA transcript

Transcription is terminated in prokaryotes by ____. a. splicing introns out and pasting exons together b. generation of a guanine cap c. generation of a poly-A tail d. transcription of an mRNA terminator sequence e. generation of a stop codon

d. transcription of an mRNA terminator sequence

Chromosomal rearrangement can occur by ____. a. point mutations b. alternative splicing c. translocation only d. translocation and inversion e. inversion only

d. translocation and inversion

The molecule in the accompanying figure is a(n) ____. a. amino acid b. steroid c. polysaccharide d. triglyceride e. phospholipid http://cnow.apps.ng.cengage.com/ilrn/books/ru2bd04t/MTQA-83611_Images/ch03_image6.JPEG

d. triglyceride

The trp operon is ____ unless tryptophan is ____. a. turned on; bound to the operator b. turned on; synthesized by the trp repressor gene c. turned off; bound to the repressor d. turned on; available in the environment e. turned off; bound to the promoter

d. turned on; available in the environment

The two amino acids in the accompanying figure both have side groups (R groups) that are ____. a. basic and polar b. acidic and polar c. uncharged and polar d. uncharged and nonpolar e. acidic and nonpolar http://cnow.apps.ng.cengage.com/ilrn/books/ru2bd04t/MTQA-83611_Images/ch03_image13.JPEG

d. uncharged and nonpolar

A channel that opens in response to changes in ionic charge across a membrane is called a(n) ____ channel. a. electric-gated b. charge-gated c. ligand-gated d. voltage-gated e. positive-gated

d. voltage-gated

The image in the accompanying figure is an example of a(n) ____. a. random coil b. double helix c. β polysaccharide d. β sheet e. α helix http://cnow.apps.ng.cengage.com/ilrn/books/ru2bd04t/MTQA-83611_Images/ch03_image15.JPEG

d. β sheet

An example of evolutionary divergence is best characterized by Darwin's observation of ____.

differences in bill shape and food habits of finches

Genetic studies of an animal show that eye color is controlled by an autosomal gene with the dominant allele (R) for red eye color and the recessive allele (r) for yellow eye color. A second autosomal gene has the dominant allele (T) for paws with thumbs and the recessive allele (t) for paws without thumbs. The genetic cross RRTT x rrtt creates offspring with genotype RrTt. One of those dihybrids is mated in a testcross (RrTt x rrtt). Based on the principle of independent assortment, the testcross should produce offspring with the phenotype ratio ____. a. 3 red-eyed with thumbs : 1 yellow-eyed without thumbs b. 9 red-eyed with thumbs : 3 yellow-eyed with thumbs: 3 red-eyed without thumbs: 1 yellow-eyed without thumbs c. 3 yellow-eyed with thumbs : 1 red-eyed without thumbs d. 1 red-eyed with thumbs : 1 yellow-eyed without thumbs e. 1 red-eyed with thumbs : 1 yellow-eyed with thumbs: 1 red-eyed without thumbs: 1 yellow-eyed without thumbs

e. 1 red-eyed with thumbs : 1 yellow-eyed with thumbs: 1 red-eyed without thumbs: 1 yellow-eyed without thumbs

A parent has a genotype of RrYy. What is the probability of this individual producing a gamete with the RY genotype? a. 3/4 b. 1/2 c. 1/8 d. 0 e. 1/4

e. 1/4

If a plant synthesized a molecule of sugar that has 12 carbons, how many turns of the Calvin cycle would be needed? a. 6 b. 3 c. 2 d. 24 e. 12

e. 12

In order to completely oxidize glucose, it takes two turns of the citric acid cycle, which yields a net of 2 ATP, 6 NADH, and 2 FADH2. How many of the 32 total ATP molecules produced in cellular respiration come from the citric acid cycle, including the contribution from the NADH and FADH2? a. 24 b. 16 c. 28 d. 32 e. 20

e. 20

How efficient is cellular respiration in extracting the energy stored in the bonds of glucose? a. 25% b. 45% c. 50% d. 80% e. 33%

e. 33%

If a cell has 36 chromosomes at the beginning of G1, how many chromosomes will be present at the end of G2? a. 18 b. 64 c. 44 d. 72 e. 36

e. 36

Answer the question using the accompanying figure. The atom depicted in this figure can form ____ covalent bonds with another atom. a. 3 b. 2 c. 0 d. 6 e. 4 http://cnow.apps.ng.cengage.com/ilrn/books/ru2bd04t/MTQA-83611_Images/ch02_image1.JPEG

e. 4

For every glucose molecule that goes through cellular respiration, how many carbon atoms are fully oxidized to CO2 in the citric acid cycle? a. 3 b. 5 c. 2 d. 1 e. 4

e. 4

Lysosomal enzymes function best at a pH of about ____. a. 6.5 b. 7 c. 8.5 d. 3 e. 5

e. 5

If a codon in the mRNA is 5'-ACG-3', then the anticodon of the proper tRNA will be ____. a. 5'-GCA-3' b. 5'-CGT-3' c. 5'-UGC-3' d. 5'-TGC-3' e. 5'-CGU-3'

e. 5'-CGU-3'

Answer the question using the accompanying graph. Which portion of the graph shows the activation energy in the absence of enzyme? a. B b. W + X c. Y + Z d. C e. A

e. A

When DNA is heated, the hydrogen bonds break and allow the two strands of DNA to separate from one another. Which sequence of DNA would be most resistant to heating, and therefore, stay double stranded longer? a. AATTGGCC b. ATGCATTC c. TACCAATT d. TGGCTTAG e. AGGAGCTC

e. AGGAGCTC

I'm a botanist looking for new species of C4 plants. Where should I focus my search? a. Quebec, Canada b. Maine c. equatorial rainforest d. The Everglades (in Florida) e. Arizona

e. Arizona

In the Hershey and Chase experiment, phage-infected bacteria and viral progeny were radioactive following bacterial infection with 32P-labeled viruses. Why? a. 32P was left outside the cell during viral infection. b. Bacteria had incorporated radioactive proteins into their DNA. c. Viral progeny had used the 32P to build new viral proteins. d. Bacteria had incorporated radioactive proteins into their cell membranes. e. Bacteria and viral progeny had incorporated 32P into their DNA.

e. Bacteria and viral progeny had incorporated 32P into their DNA.

What is the function of NADH and FADH2? a. NADH delivers electrons, while FADH2 supplies H+. b. NADH is found only in the cytosol and FADH2 only in the matrix. c. Both release energy for glycolysis to proceed forward. d. Both produce ATP by substrate-level phosphorylation. e. Both provide electrons to the electron transfer system.

e. Both provide electrons to the electron transfer system.

If three molecules of a fatty acid having the formula C16H22O2 are each joined to a molecule of glycerol (C3H8O3) by a dehydration synthesis reaction, what will be the formula of the resulting neutral fat molecule? a. C48H66O6 b. C48H72O8 c. C51H74O9 d. C51H72O8 e. C51H68O6

e. C51H68O6

Ultimately, the carbon molecules in pyruvate end up in which molecule? a. ATP b. acetate c. CoA d. NADH e. CO2

e. CO2

In what way do the various membranes of a cell differ? a. Phospholipids are found only in certain membranes. b. Only certain membranes are constructed from molecules with dual solubility. c. Some membranes have hydrophobic surfaces exposed to the cytoplasm, while others have hydrophilic surfaces facing the cytoplasm. d. Only certain membranes of a cell are selectively permeable. e. Certain proteins are unique to each membrane.

e. Certain proteins are unique to each membrane.

Which molecule is responsible for carrying the acetyl group from pyruvate into the citric acid cycle? a. NADH b. ATP c. FADH2 d. oxaloacetate e. CoA

e. CoA

How do flagella bend? a. Myosin motor proteins slide microtubules over each other. b. Microfilaments contract due to the action of kinesin. c. Myosin motor proteins slide actin filaments over each other. d. actin filaments contract due to the action of myosin e. Dynein motor proteins slide microtubule doublets over each other.

e. Dynein motor proteins slide microtubule doublets over each other.

What directly supplies the electrons for the electron transfer system? a. oxygen and water b. ATP and ADP c. various enzymes d. pyruvate and acetate e. FADH2 and NADH

e. FADH2 and NADH

How do scientists determine the annealing temperature used in PCR reactions? a. It is always 55° C because primers anneal best at lower temperatures. b. It is always 55° C because the DNA polymerase works best at this temperature. c. It is always 60° C because any other temperature would destabilize the DNA. d. It can vary from 55-60° C depending on the type of DNA polymerase being used. e. It can vary from 55-60° C depending on the primers being used.

e. It can vary from 55-60° C depending on the primers being used.

What is the fate of CoA after it delivers an acetyl group into the citric acid cycle? a. It is reused to start glycolysis. b. It remains in an inactive form until the cell dies. c. It is degraded and used for energy. d. It is used in protein synthesis. e. It is recharged with another acetate.

e. It is recharged with another acetate.

Exceptions to the principle of independent assortment were discovered and explained by ____ as resulting from genes being physically associated with each other on the same chromosome. a. Mendel b. Watson c. Crick d. Sturtevant e. Morgan

e. Morgan

Glycolysis, pyruvate oxidation, and the citric acid cycle all produce ____. a. H2O b. ATP c. FADH2 d. CO2 e. NADH

e. NADH

At the end of cellular respiration, oxygen combines with electrons of a very low energy level. How are the specific properties of oxygen beneficial to the organism that uses it as a final electron acceptor? a. Oxygen is strongly electronegative and helps pull the electrons through the electron transport chain. b. Oxygen is highly reactive and readily oxidizes methane. c. Oxygen is highly reactive and readily accepts electrons. d. Oxygen is the only molecule that can act as a final electron acceptor. e. Oxygen allows a maximum output of energy for ATP synthesis.

e. Oxygen allows a maximum output of energy for ATP synthesis.

At the start of translation, the initiator tRNA pairs with the start codon at the ____ of the ribosome. a. E (exit) site b. A (aminoacyl) site c. ribosomal binding site d. promoter e. P (peptidyl) site

e. P (peptidyl) site

Why is photorespiration more likely to occur during warm weather? a. The rubisco enzyme is very temperature sensitive and becomes less efficient in warmer temperatures, allowing it to fix O2 instead of CO2. b. Plants use up the water in their central vacuoles in warm weather, inhibiting the water-requiring light reactions; this in turn alters the activity of rubisco. c. Plants require warm weather (at least 23°C) to drive photosynthesis. d. Plants are more likely to close their stomata in the nighttime than during the day. e. Plants are more likely to dehydrate in warm weather, forcing them to close the stomata to conserve water, thus preventing CO2 from entering the leaf.

e. Plants are more likely to dehydrate in warm weather, forcing them to close the stomata to conserve water, thus preventing CO2 from entering the leaf.

The Warburg effect is the observation that cancer cells produce energy using a high rate of glycolysis followed by fermentation rather than oxidative phosphorylation. Although the exact cause is still under investigation, which explanation is most plausible? a. Tumor formation upregulates glycolytic proteins. b. Tumors attract blood vessels to increase levels of available oxygen. c. In order to grow quickly, high levels of ATP are required. d. Mutations in phosphofructokinase prevent feedback inhibition. e. Rapid cell proliferation damages mitochondrial function.

e. Rapid cell proliferation damages mitochondrial function.

Replication of DNA occurs during ____. a. G1 phase b. cytokinesis c. G0 phase d. prophase e. S phase

e. S phase

Imagine that a cell contains a genetic mutation in the gene encoding the primase enzyme, rendering it unable to synthesize RNA strands. Assuming that all of the other enzymes directly involved in DNA replication are still functional in these cells, how much of the DNA replication process would you expect to see in these cells? a. The leading strand would be synthesized, but not the lagging strand. b. Both the leading and lagging strand would be synthesized, but pieces of discontinuous strands would not be joined together. c. DNA replication would still proceed completely since RNA strands are not part of the final product of DNA replication. d. No part of the DNA replication process could occur. e. The DNA helix would be unwound by helicase, but no new strands will be produced.

e. The DNA helix would be unwound by helicase, but no new strands will be produced.

What happens when living R strain Streptococcus pneumoniae bacteria are mixed with heat-killed S strain Streptococcus pneumoniae bacteria? a. The S strain bacteria are transformed into R strain bacteria. b. The R strain bacteria are killed, and the S strain bacteria come back to life. c. The R strain bacteria are killed, and the S strain bacteria remain dead. d. The S strain bacteria come back to life. e. The R strain bacteria are transformed into S strain bacteria.

e. The R strain bacteria are transformed into S strain bacteria.

Avery, MacLeod, and McCarty continued Griffith's work with S. pneumoniae and concluded that DNA was the hereditary material. If protein was the hereditary material instead of DNA, what would happen to mice after injection of heat-killed virulent bacteria mixed with live nonvirulent bacteria after treatment with protease? a. The mice would grow tumors. b. The mice would die. c. The mice would degrade the protein. d. The mice would get sick but recover. e. The mice would live.

e. The mice would live.

How does a cell surface receptor respond to the binding of a signaling molecule? a. The cell surface receptor denatures. b. Polarization of the cell surface changes. c. The cell surface receptor flips through the membrane to the inside of the cell. d. The receptor relays a signal to another location on the cell surface. e. The signal is transduced through the plasma membrane and into the cell.

e. The signal is transduced through the plasma membrane and into the cell.

Two solutions of differing glucose concentration are placed in a container separated by a selectively permeable membrane that restricts large molecules like glucose, but allows the free diffusion of water. What will be the glucose concentration in the container after dynamic equilibrium has been reached? a. The glucose concentration of the two solutions will be identical on both sides of the membrane, but the volumes will remain unchanged. b. The volume and concentrations will be unchanged on both sides of the membrane. c. The water molecules will be evenly distributed in the container, with more glucose molecules on one side than the other. d. The volumes of the solution will be different, with a lower volume on the side that originally contained the higher concentration of glucose. e. The volumes of the solution will be different, with a higher volume on the side that originally contained the higher concentration of glucose.

e. The volumes of the solution will be different, with a higher volume on the side that originally contained the higher concentration of glucose.

What is the ultimate fate of the atoms in oxygen gas (O2) in cellular respiration? a. They are respired as CO2. b. They accept electrons in glycolysis. c. They are attached to pyruvate. d. They are attached to glucose. e. They are incorporated to water.

e. They are incorporated to water.

It has been thought that many diseases now associated with aging are related to malfunctioning mitochondria. Why are the mitochondria so important to all cells? a. They carry out anaerobic respiration. b. They are located only in vital organs. c. They are extremely large. d. They are the source of all human disease. e. They produce energy in the form of ATP.

e. They produce energy in the form of ATP.

How does RNA polymerase II bind to the DNA? a. Some transcription factors bind to the promoter while others bind to RNA polymerase II, then the two groups of proteins bind to each other. b. It binds to transcription factors in the nucleus, and the complex then binds to the promoter. c. It binds directly to the TATA box. d. It binds directly to the eukaryotic promoter sequence. e. Transcription factors first bind to the promoter, then recruit RNA polymerase II.

e. Transcription factors first bind to the promoter, then recruit RNA polymerase II.

Which system is considered an open system? a. a thermos b. a greenhouse c. the Earth d. a wine keg e. a human

e. a human

The selective permeability of a membrane refers to the ____. a. movement of a molecule from an area of high concentration to an area of low concentration b. ability of a substance to pass through any membrane c. need for carrier proteins to transport some molecules across a membrane d. ability of molecules to be transported across a membrane e. ability of only certain molecules to pass across a membrane

e. ability of only certain molecules to pass across a membrane

The removal of a phosphate group during an enzyme-catalyzed reaction takes ____. a. more time than for an uncatalyzed reaction b. 1012 years c. less time at 1000oC than at 100oC d. about 1021 milliseconds e. about 10 milliseconds

e. about 10 milliseconds

DNA polymerase ____. a. adds nucleotides to the 5' end of an existing strand to synthesize a new DNA strand b. seals nicks between adjacent segments of DNA c. synthesizes a short RNA segment to begin DNA replication d. unwinds the DNA double helix at the origin of replication e. adds nucleotides to the 3' end of an existing strand to synthesize a new DNA strand

e. adds nucleotides to the 3' end of an existing strand to synthesize a new DNA strand

If purple flower color is dominant in pea plants, a cross between true breeding P generation purple and white plants will result in ____. a. all purple flowers in the F1 generation but a lighter purple than in the parents b. all white flowers in the F1 generation c. half of the plants having purple flowers and half having white flowers d. mostly purple flowers in the F1 generation, with an occasional white flower e. all purple flowers in the F1 generation

e. all purple flowers in the F1 generation

The pre-mRNA transcript of mammalian α-tropomyosin undergoes ____ to produce different mRNAs in smooth and striated muscles. a. aminoacylation b. polyadenylation c. degeneracy d. exon shuffling e. alternative splicing

e. alternative splicing

Which functional group acts as an organic base? a. carboxyl b. phosphate c. hydroxyl d. carbonyl e. amino

e. amino

Reverse-transcriptase PCR ____. a. uses reverse transcriptase to produce mRNA copies of a gene b. uses RNA polymerase to produce mRNA copies of a gene c. uses RNA polymerase to amplify cDNA copies of RNA transcripts d. uses Taq polymerase to produce cDNA copies of RNA transcripts e. amplifies cDNA copies of RNA transcripts

e. amplifies cDNA copies of RNA transcripts

The substance H2O is considered to be ____. a. a molecule but not a compound b. a compound but not a molecule c. neither a molecule nor a compound d. both a molecule and an ion e. both a molecule and a compound

e. both a molecule and a compound

During which stages of cellular respiration is CO2 released? a. pyruvate oxidation b. electron transport system c. glycolysis d. citric acid cycle e. both pyruvate oxidation and citric acid cycle

e. both pyruvate oxidation and citric acid cycle

Chloroplasts utilize light energy to make ____. a. proteins b. steroids c. fats d. nucleic acids e. carbohydrates

e. carbohydrates

Monosaccharides and disaccharides are types of ____. a. nucleic acids b. lipids c. proteins d. amino acids e. carbohydrates

e. carbohydrates

The lowest level of biological organization that can survive and reproduce is the ____. a. DNA b. proton c. nucleus d. tissue e. cell

e. cell

In plant cells, the ____ provides cellular support and protects the cell from pathogens. a. cytoplasm b. cell membrane c. cytoskeleton d. plasmodesmata e. cell wall

e. cell wall

Suppose that an equal amount of each polysaccharide was placed in a landfill. Which polysaccharide should last the longest before it is decomposed? a. amylose b. glycogen c. amylopectin d. chitin e. cellulose

e. cellulose

What is another name for map unit? a. autosome b. genotype c. locus d. linkage e. centimorgan

e. centimorgan

The microtubule organizing center (MTOC) of an animal cell is an identifiable structure known as the ____. a. cell plate b. chromosome c. centromere d. kinetochore e. centrosome

e. centrosome

Plasmids are ____. a. small proteins that help replicate cloned genes b. protein-coding genes in the chromosome c. RNA molecules d. enzymes that cut DNA e. circular DNA molecules that replicate separately from chromosomal DNA

e. circular DNA molecules that replicate separately from chromosomal DNA

In order to prevent hair loss in men, one popular treatment is to use an inhibitor of the enzyme that converts testosterone to a different androgen (DHT). The inhibitors are steroids similar to testosterone that cannot be converted into DHT. How would you classify this type of inhibition? a. ionic inhibition b. feedback inhibition c. allosteric inhibition d. noncompetitive inhibition e. competitive inhibition

e. competitive inhibition

Schizophrenia, hypertension, and diabetes are ____. a. believed to be diseases carried on the Y chromosome b. caused only by environmental factors c. caused by a single gene mutation d. caused by a mutation to the same common allele e. considered to involve complex traits

e. considered to involve complex traits

A driver gene ____. a. does not have any effect on cancer progression b. is the unmutated form of a proto-oncogene c. contains a driver mutation that does not affect gene expression d. contains a driver mutation that causes apoptosis in normal cells e. contains a driver mutation or is expressed abnormally, conferring a growth advantage to the cell

e. contains a driver mutation or is expressed abnormally, conferring a growth advantage to the cell

The ultimate fate of the energy used by organisms is ____. a. to be recycled repeatedly without loss b. move into the environment by conduction c. transmission onto offspring d. to be recycled as metabolic energy e. conversion into heat

e. conversion into heat

Genetically altered organisms are ____. a. always genetically modified organisms b. only used in basic research c. only used in applied research d. always made using DNA technologies e. created through natural mutations or by using DNA technologies

e. created through natural mutations or by using DNA technologies

Topoisomerase functions by ____. a. binding the newly synthesized DNA to re-twist it into a double helix after replication b. unwinding the DNA double helix to expose the template strands for replication c. binding DNA polymerase to hold it tightly to the template DNA d. reading the DNA template and synthesizing a complementary strand of DNA e. creating cuts in the DNA to relieve overtwisting and strain ahead of the replication fork

e. creating cuts in the DNA to relieve overtwisting and strain ahead of the replication fork

Sexual reproduction has an advantage over asexual reproduction by ____. a. ensuring a greater number of progeny b. keeping the number of chromosomes constant more effectively c. requiring an interaction between two individuals d. allowing for the production and use of gametes e. creating more genetic diversity

e. creating more genetic diversity

Progression through the phases of the cell cycle is regulated by fluctuating concentrations of ____. a. actin b. histones c. cyclin-dependent kinases d. microtubules e. cyclins

e. cyclins

In a process called ____, cells lose their normal regulatory controls and revert partially or completely to an embryonic developmental state. a. determination b. embryogenesis c. induction d. metastasis e. dedifferentiation

e. dedifferentiation

What is the natural function of restriction endonucleases? a. DNA manipulation in vitro b. breaking phosphodiester bonds in mammalian DNA c. research applications d. regulating bacterial gene expression e. defense against viruses that infect bacteria

e. defense against viruses that infect bacteria

The change in the chromosome depicted between the top and the bottom in the accompanying figure represents a(n) ____. (Removing gene figure) a. Philadelphia chromosome b. duplication c. reciprocal translocation d. inversion e. deletion

e. deletion

The phases of each PCR cycle listed in order are ____. a. extension, denaturation, and annealing b. annealing, extension, and denaturation c. denaturation, extension, and annealing d. annealing, denaturation, and extension e. denaturation, annealing, and extension

e. denaturation, annealing, and extension

Transport of a molecule across a cell membrane by facilitated diffusion ____. a. goes against the concentration gradient b. requires the input of energy c. does not exhibit specificity for a particular type of molecule d. allows nonpolar uncharged molecules to diffuse across a membrane e. depends on a concentration gradient

e. depends on a concentration gradient

The highest level of the hierarchical classification of life is the ____. a. cell b. population c. biosphere d. ecosystem e. domain

e. domain

Electronegativity is the tendency of an atom to attract ____ to itself in a chemical bond. a. delta forces b. protons c. neutrons d. polar associations e. electrons

e. electrons

Genes with novel functions are most commonly produced by ____. a. unequal crossing-over b. nondisjunction during meiosis c. small mutations d. inversion of DNA sequences e. exon shuffling

e. exon shuffling

What can be removed from pre-mRNA during alternative splicing? a. ribosomal binding sites b. introns only c. exons only d. exons and ribosomal binding sites e. exons and introns

e. exons and introns

Scientists structure hypotheses in such a way that if they are wrong, they will be able to demonstrate it is wrong. This is the principle of ____. a. the null hypothesis b. hierarchy c. errors d. fallibility e. falsifiability

e. falsifiability

Which gene-altering event is most likely to create a new gene encoding a functional protein? a. inversion of DNA sequences b. gene duplication followed by large mutations c. transposition of DNA sequences d. exon shuffling e. gene duplication followed by small mutations

e. gene duplication followed by small mutations

A researcher wants to investigate the function of a gene without permanently altering the gene's function or activity. Which experimental approach should she choose? a. electrophoresis b. gene knockout c. bioinformatics d. RNA-seq e. gene knockdown

e. gene knockdown

Linked genes are ____. a. different alleles of the same gene b. genes whose effects combine to influence a single characteristic c. genes on two different chromosomes d. genes that affect two different traits and lead to a 9:3:3:1 phenotype ratio in a dihybrid cross e. genes that do not sort independently because they are physically near each other on the same chromosome

e. genes that do not sort independently because they are physically near each other on the same chromosome

The daughter cells produced by meiosis are ____. a. identical to each other but genetically different from the parent b. genetically different from each other but with the same chromosome number as the parent c. identical to the parent but genetically different from each other d. genetically identical to the parent and each other e. genetically different from the parent and each other

e. genetically different from the parent and each other

An organism whose genome has been engineered to include or change a genetically controlled trait is called a ____. a. clone b. bacterium c. transcriptionally modified organism d. somatic organism e. genetically modified organism (GMO)

e. genetically modified organism (GMO)

Which of these molecules has the most potential energy? a. pyruvate b. FADH2 c. ATP d. NADH e. glucose

e. glucose

The surface receptors that recognize and bind signaling molecules are ____. a. promoters b. ligands c. glycolipids d. phospholipids e. glycoproteins

e. glycoproteins

If you want to buy a colored light bulb for your indoor plants, which color would be the least effective? a. yellow b. blue c. orange d. red e. green

e. green

The molecule in the accompanying figure is mannose, an example of a ____ sugar. a. pentose b. tetrose c. heptose d. triose e. hexose

e. hexose

The hydrogen-bond lattice causes water to have an unusually ____ specific heat, an unusually ____ heat of vaporization, and an unusually ____ density in solid form. a. high; low; high b. high; high; high c. low; low; high d. low; low; low e. high; high; low

e. high; high; low

Which was the first mammalian genome sequenced? a. gorilla b. chimpanzee c. mouse d. sheep e. human

e. human

The Human Genome Project completed in 2003 focused on sequencing the genome(s) of _____. a. humans and prokaryotes only b. humans only c. the mouse only d. bacteria only e. humans and other model organisms

e. humans and other model organisms

If a monohybrid cross results in 1:2:1 genotypic and phenotypic ratios in the offspring, then which type of inheritance might be at work? a. pleiotropy b. polygenic inheritance c. epistasis d. dominance e. incomplete dominance

e. incomplete dominance

When growth factors bind to receptors on the cell surface, the signaling cascade will ____. a. trigger mitosis without the other stages of the cell cycle b. cause the cells to enter the G0 state c. prevent cell division d. trigger cell death e. initiate cell growth

e. initiate cell growth

Which sequence of the cell cycle is correct? a. anaphase, interphase, telophase, prometaphase, prophase, metaphase b. prophase, metaphase, interphase, telophase, anaphase c. interphase, metaphase, prometaphase, prophase, telophase, anaphase d. prometaphase, anaphase, prophase, telophase, interphase, metaphase e. interphase, prophase, prometaphase, metaphase, anaphase, telophase

e. interphase, prophase, prometaphase, metaphase, anaphase, telophase

Malate produced by the CAM pathway in CAM plants ____. a. is stored in mesophyll cells b. is stored during the day in the stroma c. is immediately used in cellular respiration d. diffuses to bundle sheath cells for degradation in the lysosomes e. is stored during the night in the central vacuole

e. is stored during the night in the central vacuole

If a stretch of human double-stranded DNA contains 47% G and C bases, then ____. a. it contains 47% A and T bases b. there are more purines than pyrimidines c. there are more pyrimidines than purines d. there are no genes in this stretch of DNA e. it contains 53% A and T bases

e. it contains 53% A and T bases

A child swinging on a swing utilizes which type(s) of energy? a. kinetic energy only because the child is in constant motion b. kinetic and potential energy only, but in constantly changing ratios: when changing direction it is pure potential energy; at the bottom of the arc, it is pure kinetic energy c. chemical energy only, because it is the child's metabolism that powers the muscles that make the swing move d. potential energy only, because the child has to invest energy to get the swing to move e. kinetic, potential, and chemical energy: the child powers the swing with chemical energy in the muscle cells and the swing moves like a pendulum with changing ratios of kinetic and potential energy.

e. kinetic, potential, and chemical energy: the child powers the swing with chemical energy in the muscle cells and the swing moves like a pendulum with changing ratios of kinetic and potential energy.

About 10-20% of patients with Leigh Syndrome, a mitochondrial disease, have a mutation in MT-ATP6, a gene that codes for ATP synthase. These patients often experience high levels of _____ in their cells due to an increase in levels of pyruvate that are unable to convert to acetyl-CoA.

e. lactate

The disaccharide in the accompanying figure is ____. a. maltose b. fructose c. cellulose d. sucrose e. lactose http://cnow.apps.ng.cengage.com/ilrn/books/ru2bd04t/MTQA-83611_Images/ch03_image3.JPEG

e. lactose

Substance A is synthesized in the liver, travels through the circulatory system bound to a carrier protein, and causes a change in gene expression in a target cell. This is an example of ____. a. paracrine signaling b. autocrine signaling c. local signaling d. communication by direct contact e. long-distance signaling

e. long-distance signaling

At one point in human development, tissue connects the fingers, giving the hand a "webbed" appearance. Enzymes eventually destroy the cells of the webbing and the fingers separate. These enzymes are probably localized in the ____. a. smooth endoplasmic reticulum b. chromosomes c. nucleus d. vacuoles e. lysosomes

e. lysosomes

Small ribonucleoprotein particles (snRNPs) are involved in ____. a. initiation of transcription b. initiation of translation c. termination of translation d. aminoacylation of tRNA e. mRNA splicing

e. mRNA splicing

Photosynthesis and cellular respiration are examples of ____. a. anabolism b. synthesis c. cleavage d. catabolism e. metabolism

e. metabolism

Colchicine, a chemical extracted from the autumn crocus (Colchicum autumnale), inhibits the formation of microtubules. Mitotic cells exposed to colchicine will therefore be arrested at ____. a. interphase b. telophase c. anaphase d. prophase e. metaphase

e. metaphase

See the provided genetic code table. The start codon for translation directs incorporation of which amino acid? a. lysine b. phenylalanine c. no amino acid is encoded; the start codon simply begins the process d. glycine e. methionine

e. methionine

A small molecule of RNA is transcribed in the nucleus. It is folded, cleaved by dicer protein, and then binds to a target molecule of mRNA. This molecule of RNA must be ____. a. a transcript for a repressor protein b. siRNA c. an mRNA that never received its poly-A tail d. an mRNA that was not properly capped e. miRNA

e. miRNA

The most commonly used unit for measuring cell size is a ____. a. decimeter (dm) b. nanometer (nm) c. millimeter (mm) d. centimeter (cm) e. micrometer (μm)

e. micrometer (μm)

The microtubules of the mitotic spindle originate from the ____ in both plant and animal cells. a. centromere b. centriole c. chromatid d. centrosome e. microtubule organizing centers (MTOCs)

e. microtubule organizing centers (MTOCs)

Over time, cancerous cells typically lose the cell adhesion molecules embedded in their plasma membrane. Loss of these molecules is best associated with which of the following traits of cancer cells? a. angiogenesis b. loss of chromosomes c. increased rate of cell division d. production of new proteins e. migration to new locations in the body

e. migration to new locations in the body

Which eukaryotic organelle(s) contain its/their own DNA? a. endoplasmic reticulum only b. mitochondria only c. mitochondria and endoplasmic reticulum d. chloroplasts only e. mitochondria and chloroplasts

e. mitochondria and chloroplasts

The Na+/K+ pump creates a ____ charge inside the cell and a ____ charge outside the cell. a. positive; negative b. negative; negative c. neutral; positive d. positive; positive e. negative; positive

e. negative; positive

Waxy coatings, such as those found on skin, hair, and feathers of some animals and the cuticle of some plants, are commonly used by living organisms for protection against water loss and for lubrication. Such waxes are considered to be a type of ____. a. phospholipid b. triglyceride c. fatty acid d. steroid e. neutral lipid

e. neutral lipid

Molecules such as H-H and O=O are held together by ____. a. ionic bonds b. van der Waals forces c. polar covalent bonds d. hydrogen bonds e. nonpolar covalent bonds

e. nonpolar covalent bonds

What are the correct order of the basic steps of the scientific method? a. predict → hypothesize → experiment → observe → interpret b. hypothesize → predict → experiment → observe → interpret c. hypothesize → observe → predict → experiment → interpret d. observe → predict → hypothesize → experiment → interpret e. observe → hypothesize → predict → experiment → interpret

e. observe → hypothesize → predict → experiment → interpret

Unequal crossing over _____. a. is the result of alternative splicing b. occurs between heterologous chromosomes c. is an abnormal crossover event that occurs during mitosis d. generates a single point mutation e. occurs between different points on homologous chromosomes

e. occurs between different points on homologous chromosomes

Genes under positive control are ____. a. regulated by feedback inhibition b. always expressed c. controlled by several promoters to increase transcription d. expressed unless a repressor protein is present e. off until they are turned on

e. off until they are turned on

Regulatory proteins bind to the ____ of a gene operon. a. transcription unit and promoter b. promoter only c. transcription unit only d. operator and promoter e. operator only

e. operator only

Replication of a bacterial chromosome begins at a specific region called the ____. a. ter b. replication fork c. rep d. beg e. ori

e. ori

Amino acids are linked together by ____ bonds. a. glycosidic b. hydrogen c. disulfide d. phosphodiester e. peptide

e. peptide

The two major categories of extracellular signaling molecules that bind to cell surface receptors are ____. a. steroid hormones and neurotransmitters b. growth hormones and vitamins c. peptide hormones and steroid hormones d. neurotransmitters and vitamins e. peptide hormones and neurotransmitters

e. peptide hormones and neurotransmitters

Which phase(s) of the Calvin cycle require ATP? a. phase III only b. phase I only c. phase II only d. phases I and II only e. phases II and III only

e. phases II and III only

Once activated, cAMP is quickly degraded to AMP by ____, switching off the signal pathway. a. diacylglycerol b. adenylyl cyclase c. phospholipase C d. acetylcholinesterase e. phosphodiesterase

e. phosphodiesterase

Which molecule is the main structural component of biological membranes? a. protein b. starch c. triglyceride d. steroid e. phospholipid

e. phospholipid

The ____ regulates the movement of molecules in and out of the cell. a. cytoplasm b. nucleus c. DNA d. cystol e. plasma membrane

e. plasma membrane

In agarose gel electrophoresis, DNA molecules move towards the ____ pole because they ____. a. bottom; have a greater density than the gel b. bottom; are pulled by gravity c. bottom; are pulled by a magnetic force d. negative; are positively charged e. positive; are negatively charged

e. positive; are negatively charged

The ____ , located ____ of the transcription start point, is the site at which RNA polymerase associates with DNA to begin transcription. a. intron; downstream b. initiator; upstream c. promoter; downstream d. initiator; downstream e. promoter; upstream

e. promoter; upstream

During DNA sequence annotation, which feature is not identified? a. origins of replication b. noncoding RNA genes c. pseudogenes d. protein coding genes e. protein interactions

e. protein interactions

The process of fertilization joins male and female gametes ____. a. that contain a greater number of maternal chromosomes b. that contain a greater number of paternal chromosomes c. with the best adaptive traits d. with the fewest mutations e. randomly

e. randomly

In the process of mRNA splicing, the lariat structure is the ____. a. region where two exons are pasted together b. enzyme that cuts the pre-mRNA c. region where two introns are pasted together d. splicing complex e. released intron

e. released intron

Trace the correct path in the endomembrane followed by a protein, beginning with its site of synthesis in the rough ER. a. rough ER → smooth ER → lysosome → plasma membrane b. rough ER → vesicle → smooth ER → plasma membrane c. rough ER → smooth ER → Golgi complex → plasma membrane d. rough ER → vesicle → lysosome → plasma membrane e. rough ER → Golgi complex → vesicle → plasma membrane

e. rough ER → Golgi complex → vesicle → plasma membrane

About 10-15% of African Americans in the United States are carriers for ____, an autosomal recessive genetic disorder in which a defective version of the hemoglobin protein is produced. a. Duchenne muscular dystrophy b. cystic fibrosis c. achondroplasia d. phenylketonuria e. sickle-cell anemia

e. sickle-cell anemia

Many cancers can be identified based on microarray analysis of _____. a. DNA probes b. Y chromosome DNA c. genes in red blood cells d. mitochondrial DNA e. signature genes

e. signature genes

A group of organisms in which the individuals are so closely related in structure, biochemistry, and behavior that they can successfully interbreed is a(n) ____. a. class b. kingdom c. order d. genus e. species

e. species

After one minute without oxygen, brain cells begin to die. After three minutes, this damage is likely to cause severe neurological deficits. The dependence of brain cells on oxygen for survival indicates that these cells are ____. a. transitional aerobes b. facultative aerobes c. strict anaerobes d. facultative anaerobes e. strict aerobes

e. strict aerobes

The goal(s) of proteomics include(s) the determination of protein_____. a. location only b. sequence, interactions, and structure c. function only d. structure only e. structure, function, location, and interactions

e. structure, function, location, and interactions

The disaccharide in the accompanying figure is ____. a. cellulose b. maltose c. lactose d. galactose e. sucrose http://cnow.apps.ng.cengage.com/ilrn/books/ru2bd04t/MTQA-83611_Images/ch03_image2.JPEG

e. sucrose

The water strider shown in the figure above is able to stand on water because of the ____ of water. a. covalent bonds b. hydration layer c. density d. van der Waals forces e. surface tension

e. surface tension

The last protein in a signaling pathway is called the ____. a. second messenger b. final acceptor c. electron acceptor d. effector protein e. target protein

e. target protein

Ras proteins are of interest to researchers because of their role in ____. a. eliciting the fight-or-flight response b. linking plant hormones to germination c. relieving cluster headaches d. reproduction e. the development of many types of cancer

e. the development of many types of cancer

During every energy transformation, it can be said that ____. a. the system becomes more organized b. there is an increase in the free energy of the universe c. the entropy of the universe decreases d. there is a change in the total energy of the universe e. the entropy of the universe increases

e. the entropy of the universe increases

If a hypothetical human female of genotype XX had no Barr body in any of her cells, ____. a. she would have a Y chromosome b. she would be phenotypically male c. she would have Turner syndrome d. she would be considered triploid e. the genes on both X chromosomes would be expressed

e. the genes on both X chromosomes would be expressed

According to the fluid mosaic model of cell membranes, the fluid part of the model refers to ____. a. a thin layer of water found sandwiched between the two layers of phospholipids b. the constant movement of the hydrophilic tails in the interior of the membrane c. the free movement of cholesterol molecules within the membrane d. the frequent flip-flop of phospholipids from one side of the membrane to the other e. the phospholipid molecules which vibrate, spin, and exchange places within the same layer of the bilayer

e. the phospholipid molecules which vibrate, spin, and exchange places within the same layer of the bilayer

Reversible reactions in a cell rarely reach equilibrium because ____. a. they are highly regulated to prevent overuse of reactants b. a cell at equilibrium is dead c. cells have no way of measuring the relative ratios of reactants and products d. conditions in the cell change too rapidly for any reaction to ever reach equilibrium e. the products are generally reactants in other reactions and are thus immediately used

e. the products are generally reactants in other reactions and are thus immediately used

In an exothermic reaction, ____. a. heat energy is absorbed b. the reactants have less potential energy than the products c. ATP is phosphorylated d. H (enthalpy) = 0 e. the products have less potential energy than the reactants

e. the products have less potential energy than the reactants

What is the role of Cdks? a. to allow the cell cycle to work forward or backward b. to check for proper attachment of spindle fibers to chromosomes c. to remove phosphate groups from cyclins d. to arrest the cell cycle e. to add phosphate groups to target proteins

e. to add phosphate groups to target proteins

You have type A blood (genotype IAi). Who can you donate blood to in an emergency? a. type A only b. type O only c. types A and B, not O d. type AB only e. types A and AB

e. types A and AB

Which type of chemical linkage is the weakest? a. hydrogen bonds b. nonpolar covalent bonds c. polar covalent bonds d. ionic bonds e. van der Waals forces

e. van der Waals forces

If we apply Darwin's theories to many characteristics that affect survival and reproduction, natural selection would cause the populations to become more different over time, a process called ____.

evolutionary divergence

Recently discovered fossils reveal that many dinosaurian ancestors of birds had ____.

feathers

Which structure(s) grow(s) just in front of animal tissues where only the Hoxc6 gene is expressed?

forelimbs only

The concept of ____, the view that slow and continuous physical processes, acting over long periods of time, produced Earth's major geological features, was proposed by ____.

gradualism; James Hutton

The wings of bats and birds are ____.

homologous because they have similar internal bone structure inherited from a common ancestor

According to Lamarck's principle of use and disuse, the growth of body parts is related to____.

how much a particular body part is used

Lamarck argued that long-legged wading birds are descended from short-legged ancestors that stretched their legs to stay dry while feeding in shallow water, and consequently produced offspring with slightly longer legs. Which mechanism did he use to support this argument?

inheritance of acquired characteristics

The modern synthesis is NOT based on ____.

linking population growth with variation to explain natural selection

Darwin's primary scientific achievement was identifying the ____.

mechanism by which populations of organisms change over time

A small evolutionary shift in the size of the bill of a finch species is an example of ____.

microevolution

Which proteins would be considered peripheral proteins? a. aquaporins b. carrier proteins c. microtubules d. receptors e. cell adhesion proteins

microtubules

Woolly mammoths were determined to be more closely related to Asian elephants than to African elephants on the basis of ____.

mitochondrial and nuclear DNA sequences

During Mendel's time, a widely accepted theory called ____ suggested that evolution occurred in spurts rather than by gradual change.

mutationism

Darwin hypothesized that advantageous hereditary traits in nature would become more common in populations due to the process of ____.

natural selection

A mutation in the Hoxc8 gene in the ancestor of modern snakes caused its descendants to have ____.

no forelimbs or necks

Nucleic acids are long chains of ____. a. amino acids b. peptides c. sugars d. nucleotides e. lipids

nucleotides

While on the H.M.S. Beagle, Darwin observed that ____.

organisms in different South American habitats resembled each other, but did not resemble organisms in similar European habitats

Which pairing between evolutionary evidence and a biological discipline is NOT correct?

pesticide resistance: historical biogeography

Biological evolution occurs in ____ when specific processes cause genomes of organisms to differ from those of their ancestors.

populations

Which morphological feature in lizards, mammals, and birds provides evidence of their descent from a shared ancestor?

presence of limb buds in embryonic development

Early in the twentieth century, some scientists embraced the notion of orthogenesis, the idea that evolution ____.

produces new species with the goal of improvement

The "mosaic" part of the fluid mosaic model refers to the membrane ____. a. functions b. layers c. cholesterol d. proteins e. phospholipids

proteins

According to the modern synthesis, macroevolution results from ____.

the gradual accumulation of microevolutionary changes

New genetic variations sometimes become more common within populations because ____.

the resulting proteins are advantageous and selected for by nature

Structures in an organism that have no current function are referred to as ____.

vestigial

Pigs have feet with toes that do not touch the ground. These toes are examples of ____.

vestigial structures