Final Exam

A black guinea pig crossed with a guinea pig with albinism produced 12 black offspring. When the albino was crossed with a second black animal, six blacks and six albinos were obtained. What is the best explanation for this genetic situation? A. Albinism is a recessive trait; black is a dominant trait. B. Albinism is a dominant trait; black is incompletely dominant. C. Albinism and black are codominant. D. Albinism is a recessive trait; black is codominant.

A

A cell with a predominance of rough endoplasmic reticulum is most likely ________. A. producing large quantities of proteins for secretion B. producing large quantities of carbohydrates for storage in the vacuole C. producing large quantities of carbohydrates to assemble an extensive cell wall matrix D. producing large quantities of proteins in the cytosol

A

A characteristic 9 + 2 arrangement of microtubules, consisting of nine doublets of microtubules surrounding a pair of single microtubules is associated with ________. A. eukaryotic flagella and motile cilia B. eukaryotic flagella, motile cilia, and nonmotile cilia C. centrioles and basal bodies D. bacterial flagella

A

A newborn who is accidentally given a drug that destroys the thymus would most likely _____. A. be unable to differentiate and mature T cells B. lack innate immunity C. be unable to genetically rearrange antigen receptors D. have a reduced number of B cells and be unable to form antibodies

A

A nonfunctional CD4 protein on a helper T cell would result in the helper T cell being unable to ________. A. interact with a class II MHC-antigen complex B. lyse tumor cells C. respond to circulating viral antigens D. stimulate a cytotoxic T cell

A

A person on a strict diet and exercise regimen lost 7 kg (about 15 pounds) of body fat in just two weeks. What is the most likely way that the lost fat left the body? A. It was released as CO2 and H2O. B. It was converted to ATP, which weighs much less than fat. C. It was eliminated from the body as feces. D. It was converted to heat and then released.

A

A phospholipid bilayer with equal amounts of saturated and unsaturated fatty acids displays a specific permeability to glucose. What effect will increasing the proportion of unsaturated fatty acids in the bilayer have on the membrane's permeability to glucose? A. Permeability to glucose will increase. B. Permeability will decrease initially then increase as the bilayer fills with glucose. C. Permeability to glucose will stay the same. D. Permeability to glucose will decrease.

A

A salamander relies on hydrogen bonding to stick to various surfaces. Therefore, a salamander would have the greatest difficulty clinging to a _____. A. surface of hydrocarbons B. surface of mostly carbon-nitrogen bonds C. slightly damp surface D. surface of mostly carbon-oxygen bonds

A

A series of enzymes catalyze the reactions in the metabolic pathway X → Y → Z → A. Product A binds to the enzyme that converts X to Y at a position remote from its active site. This binding decreases the activity of the enzyme. With respect to the enzyme that converts X to Y, substance A functions as ________. A. an allosteric inhibitor B. a competitive inhibitor C. an intermediate D. the substrate

A

According to the fluid mosaic model, a membrane ________. A. is composed of a fluid bilayer of phospholipids with embedded amphipathic proteins B. is composed of a mosaic of fluid polysaccharides and amphipathic proteins C. is composed of a fluid bilayer of phospholipids between two layers of hydrophilic proteins D. is composed of a single layer of fluid phospholipids between two layers of hydrophilic proteins

A

Biologists sometimes divide living organisms into two groups: autotrophs and heterotrophs. These two groups differ in ________. A. their sources of carbon B. their mode of inheritance C. the way that they generate ATP D. their electron acceptors

A

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

A

Chloramphenicol is an antibiotic that targets prokaryotic (70S) ribosomes, but not eukaryotic (80S) ribosomes. Which of these questions stems from this observation, plus an understanding of eukaryotic origins? A. If chloramphenicol inhibits prokaryotic ribosomes, should it not also inhibit mitochondrial ribosomes? B. Can chloramphenicol also be used to control human diseases that are caused by archaeans? C. Why aren't prokaryotic ribosomes identical to eukaryotic ribosomes? D. Can chloramphenicol pass through the capsules possessed by many cyanobacteria?

A

Cohesion, surface tension, and adhesion are the properties of water molecules that ________. A. are a result of hydrogen bonding B. are a result of polar covalent bonding C. increase when temperature increases D. increase when pH increases

A

Even though plants cells carry out photosynthesis, they still use their mitochondria for oxidation of pyruvate. Under what conditions will plant cell mitochondria be active in this process? A. in all cells, with or without light B. only in cells that store glucose in the form of starch and only in the dark C. only in photosynthetic cells in the light, while photosynthesis occurs concurrently D. in photosynthesizing cells in the light, and in other cells in the dark

A

For a science fair project, two students decided to repeat the Hershey and Chase experiment, with modifications. They decided to radioactively label the nitrogen of the DNA, rather than the phosphate. They reasoned that each nucleotide has only one phosphate and two to five nitrogen atoms. Thus, labeling the nitrogen atoms would provide a stronger signal than labeling the phosphates. Why won't this experiment work? A. Amino acids (and thus proteins) also have nitrogen atoms; thus, the radioactivity would not distinguish between DNA and proteins. B. Radioactive nitrogen has a half-life of 100,000 years, and the material would be too dangerous for too long. C. There is no radioactive isotope of nitrogen. D. Although there are more nitrogens in a nucleotide, labeled phosphates actually have 16 extra neutrons; therefore, they are more radioactive.

A

HIV is inactivated in the laboratory after a few minutes of sitting at room temperature, but the flu virus is still active after sitting for several hours. What are the practical consequences of these findings? A. The flu virus can be transmitted more easily from person to person than HIV B. HIV can be transmitted more easily from person to person than the flu virus C. This property of HIV makes it more likely to be a pandemic than the flu virus D. Disinfecting surfaces is more important to reduce the spread of HIV than the flu

A

HIV's genome of RNA includes the code for reverse transcriptase (RT), an enzyme that acts early in infection to synthesize a DNA genome off of an RNA template. The HIV genome also codes for protease (PR), an enzyme that acts later in infection by cutting long viral polyproteins into smaller, functional proteins. Both RT and PR represent potential targets for antiretroviral drugs. Drugs called nucleoside analogs (NA) act against RT, whereas drugs called protease inhibitors (PI) act against PR. Which of the following treatment options would most likely avoid the evolution of drug-resistant HIV (assuming no drug interactions or side effects)? A. Use moderate doses of NA and two different PIs at the same time for several months. B. Use a single PI, but slowly increase the dosage over the course of a week. C. Use a series of NAs, one at a time, and change about once a week. D. Use high doses of NA and a PI at the same time for a period not to exceed one day.

A

Homo sapiens have 23 pairs of chromosomes. This implies that ________. A. 46 double-stranded DNA molecules are present in each somatic cell B. 23 double-stranded DNA molecules are present in each somatic cell C. 23 single-stranded DNA molecules are present in each somatic cell D. several hundreds of genes are present on DNA but not on the chromosomes

A

How does the primary transcript in a prokaryotic cell compare to the functional mRNA? A. the primary transcript is the same size as the mRNA B. the primary transcript is larger than the mRNA C. the primary transcript and the mRNA both contain introns D. the primary transcript is smaller than the mRNA

A

How is a viral antigen, like EBV, recognized by T cells? A. An antigen fragment is presented within class I MHC to the T cell receptor. B. Interferon proteins stick to the surface of infected cells. C. T cells recognize antibodies that have bound to viral particles. D. The virus is engulfed by T cells using Toll-like receptors.

A

Human immunodeficiency virus (HIV) infects cells that have both CD4 and CCR5 cell surface molecules. The viral nucleic acid molecules are enclosed in a protein capsid, and the protein capsid is itself contained inside an envelope consisting of a lipid bilayer membrane and viral glycoproteins. One hypothesis for viral entry into cells is that binding of HIV membrane glycoproteins to CD4 and CCR5 initiates fusion of the HIV membrane with the plasma membrane, releasing the viral capsid into the cytoplasm. An alternative hypothesis is that HIV gains entry into the cell via receptor-mediated endocytosis, and membrane fusion occurs in the endocytotic vesicle. To test these alternative hypotheses for HIV entry, researchers labeled the lipids on the HIV membrane with a red fluorescent dye. In an HIV-infected cell producing HIV virus particles, the viral glycoprotein is expressed on the plasma membrane. How do the viral glycoproteins get to the plasma membrane? They are synthesized ________. A. by ribosomes in the rough ER and arrive at the plasma membrane in the membrane of secretory vesicles B. on ribosomes on the plasma membrane C. by ribosomes in the rough ER, secreted from the cell, and inserted into the plasma membrane from the outside D. on free cytoplasmic ribosomes and then inserted into the plasma membrane

A

If a cell at metaphase of mitosis contains 20 sister chromatids, how many chromosomes will be present in a G1 cell? A. 10 B. 20 C. 40 D. 5

A

If a cell has completed meiosis I and the first cytokinesis, and is just beginning meiosis II, which of the following is an appropriate description of its genetic contents? A. It has half the amount of DNA as the cell that began meiosis. B. It has one-fourth the DNA and one-half the chromosomes as the parent cell. C. It is genetically identical to another cell formed from the same meiosis I event. D. It has half the chromosomes but twice the DNA of the parent cell.

A

If cell X enters meiosis, and nondisjunction of one chromosome occurs in one of its daughter cells during meiosis II, how will this affect the gametes at the completion of meiosis? A. One-quarter of the gametes descended from cell X will be n + 1, one-quarter will be n - 1, and half will be n. B. All the gametes descended from cell X will be diploid. C. Half of the gametes descended from cell X will be n + 1, and half will be n - 1. D. Two of the four gametes descended from cell X will be haploid, and two will be diploid.

A

If one strand of a DNA molecule has the sequence of bases 5-ATTGCA-3, the mRNA synthesized following the template will be ________. A. 3-UAACGU-5 B. 5-TGCAAT-3 C. 5-TAACGT-3 D. 5-UGCAAU-3

A

In E. coli, to repair a thymine dimer by nucleotide excision repair, in which order do the necessary enzymes act? A. nuclease, DNA polymerase, DNA ligase B. helicase, DNA polymerase, DNA ligase C. DNA ligase, nuclease, helicase D. nuclease, DNA polymerase, RNA primase

A

In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of the allele a is 0.3. What is the frequency of individuals that are homozygous for this allele? A. 0.09 B. 0.9 C. 9.0 D. 0.49

A

In a resting potential, an example of a cation that is more abundant as a solute in the cytosol of a neuron than it is in the interstitial fluid outside the neuron is _____. A. K+ B. Na+ C. Cl- D. Ca++

A

In autotrophic bacteria, where is chlorophyll located? A. in infolded regions of the plasma membrane B. in the cell wall C. in the nucleoid D. in chloroplast membranes

A

In experiments where researchers suspect that a hormone may be responsible for a certain physiological effect, they may cut the neurons leading to the organ where the effect being studied occurs. What is the purpose of cutting these neurons? A. to make sure that the effect is not occurring through actions in the nervous system B. to numb the organ so that it can be probed without inducing pain in the lab animal C. to impair the normal functions of the organ so that the hormonal effect can be more easily studied D. to make sure that the organ being affected cannot function unless the researchers stimulate it with an external electrical probe

A

In the absence of oxygen, yeast cells can obtain energy by fermentation, which results in the production of which of the following sets of molecules? A. ATP, CO2, and ethanol (ethyl alcohol) B. ATP, CO2, and acetyl CoA C. ATP, NADH, and ethanol D. ATP, CO2, and lactate

A

In the cells of many eukaryotic species, the nuclear envelope has to disappear to permit which of the following events in the cell cycle? A. attachment of microtubules to kinetochores B. separation of the centrosomes C. DNA synthesis D. condensation of the chromosomes

A

Low humidity in the atmosphere on a hot day ________. A. helps in cooling because water evaporates from the skin faster B. does not help in cooling because water evaporates from the skin faster C. helps in cooling because skin absorbs water from the atmosphere D. does not help in cooling because skin absorbs water from the atmosphere

A

Microevolutions occur when ________. A. changes in allele frequencies in a population occur over generations B. individuals within all species vary in their phenotypic traits C. a bird has a beak of a particular size that does not grow larger during a drought D. gene flow evenly transfers alleles between populations

A

Phenylketonuria is an inherited disease caused by a recessive autosomal allele. If a woman and her husband are both carriers, what is the probability that their first child will be a phenotypically normal girl? A. 3/8 B. 3/16 C. 1/4 D. 1/16

A

Red-green color blindness is a sex-linked recessive trait in humans. Two people with normal color vision have a color-blind son. What are the genotypes of the parents? A. XNXn and XNY B. XNXN and XNY C. XNXN and XnY D. XnXn and XnY

A

Refer to the following figure to answer the questions below. 3H2 + N2 ↔ 2NH3 Which of the following is true for the reaction? A. Ammonia is being formed and decomposed simultaneously. B. Only the forward or reverse reactions can occur at one time. C. The reaction is nonreversible. D. Hydrogen and nitrogen are the reactants of the reverse reaction.

A

Research indicates that ibuprofen, a drug used to relieve inflammation and pain, is a mixture of two enantiomers; that is, molecules that _____. A. are mirror images of each other B. differ in the arrangement of atoms around their double bonds C. have identical chemical formulas but differ in the branching of their carbon skeletons D. differ in the location of their double bonds

A

Researchers investigating the mechanism of vesicular transport assembled a cell-free system that included microtubule tracks, vesicles, and ATP. However, they observed no movement of transport of vesicles in this system. What were they missing? A. motor proteins B. intermediate filaments C. an axon D. contractile microfilaments

A

Several epidemic microbial diseases of earlier centuries incurred high death rates because they resulted in severe dehydration due to vomiting and diarrhea. Today they are usually not fatal because we have developed which of the following types of treatments? A. hydrating drinks with high concentrations of salt and glucose B. antiviral medications that are efficient and work well with most viruses C. intravenous feeding techniques D. medications to slow blood loss

A

Sulfur is in the same column of the periodic table as oxygen, but has electronegativity similar to carbon. Compared to water molecules, molecules of H2S will _____. A. not form hydrogen bonds with each other B. have a higher capacity to absorb heat for the same change in temperature C. have a greater tendency to form hydrogen bonds with each other D. have greater cohesion to other molecules of H2S

A

The complexity and variety of organic molecules is due to _____. A. the chemical versatility of carbon atoms B. the diverse bonding patterns of nitrogen C. their interaction with water D. the variety of rare elements in organic molecules

A

The following experiment is used for the following question. A researcher discovered a species of moth that lays its eggs on oak trees. Eggs are laid at two distinct times of the year: early in spring when the oak trees are flowering and in midsummer when flowering is past. Caterpillars from eggs that hatch in spring feed on oak flowers and look like oak flowers, but caterpillars that hatch in summer feed on oak leaves and look like oak twigs. How does the same population of moths produce such different-looking caterpillars on the same trees? To answer this question, the biologist caught many female moths from the same population and collected their eggs. He put at least one egg from each female into eight identical cups. The eggs hatched, and at least two larvae from each female were maintained in one of the four temperature and light conditions listed below. Temperature Day Length Springlike Springlike Springlike Summerlike Summerlike springlike Summerlike summerlike In each of the four environments, one of the caterpillars was fed oak flowers, the other oak leaves. Thus, there were a total of eight treatment groups (4 environments × 2 diets). Which one of the following is not a plausible hypothesis that can be tested in this experiment? A. Differences in air pressure, due to differences in elevation, trigger the development of different types of caterpillars. B. Differences in diet trigger the development of different types of caterpillars. C. The cooler temperatures of spring trigger the development of flowerlike caterpillars. D. The longer day lengths of summer trigger the development of twig-like caterpillars.

A

The free energy for the oxidation of glucose to CO2 and water is -686 kcal/mol, and the free energy for the reduction of NAD+ to NADH is +53 kcal/mol. Why are only two molecules of NADH formed during glycolysis when it appears that as many as a dozen could be formed? A. Most of the free energy available from the oxidation of glucose remains in pyruvate, one of the products of glycolysis. B. Most of the free energy available from the oxidation of glucose is used in the production of ATP in glycolysis. C. There is no CO2 or water produced as products of glycolysis. D. Glycolysis is a very inefficient reaction, with much of the energy of glucose released as heat.

A

The mechanism of photophosphorylation is most similar to which of the following processes? A. oxidative phosphorylation in cellular respiration B. substrate-level phosphorylation in glycolysis C. reduction of NADP+ D. the Calvin cycle

A

The oxygen released by photosynthesis is produced by which of the following processes? A. splitting water molecules B. chemiosmosis C. the electron transfer system of photosystem I D. the electron transfer system of photosystem II

A

Vaccination offers protection against future exposure to pathogens because it ________. A. triggers clonal expansion of lymphocytes B. enhances the activity of macrophages C. promotes inflammation D. stimulates the complement system

A

Vinblastine, a drug that inhibits microtubule polymerization, is used to treat some forms of cancer. Cancer cells given vinblastine would be unable to _____. A. separate chromosomes during cell division B. migrate by amoeboid movement C. maintain the shape of the nucleus D. form cleavage furrows during cell division

A

What happens to a glucose molecule when it loses a hydrogen atom as the result of an oxidation-reduction reaction? A. The glucose molecule is oxidized. B. The glucose molecule is an oxidizing agent. C. The glucose molecule is hydrolyzed. D. The glucose molecule is reduced.

A

What is a primary function of integrins? A. transmitting signals from the extracellular matrix to the cytoskeleton B. linking the primary and secondary cell walls in plants C. connecting intermediate filaments to microtubules involved in vesicular transport D. transmitting chemical signals from the Golgi apparatus to the plasma membrane

A

What is the maximum number of hydrogen atoms that can be covalently bonded in a molecule containing two carbon atoms? A. six B. eight C. four D. two

A

What is the only type of chemical signal that does not alter the physiology of the animal producing that signal? A. pheromones B. neuroendocrine C. paracrine D. neural

A

When an action potential from a motor neuron arrives at the neuromuscular junction (NMJ), a series of events occurs that leads to muscle contraction. Which of the following events will occur last (that is, after all of the others listed below)? A. conformational change in troponin B. depolarization of the muscle cell C. release of Ca2+ from the sarcoplasmic reticulum D. acetylcholine (ACh) release

A

When chiasmata can first be seen in cells using a microscope, which of the following processes has most likely occurred? A. prophase I B. anaphase II C. the separation of homologs D. meiosis II

A

Which of the following carbon molecules does not have the bond angle of 109.5°? A. C2H4 B. C2H6 C. CH4 D. C3H8

A

Which of the following is an example of monosomy in humans? A. Turner syndrome B. Down syndrome C. Klinefelter syndrome D. trisomy X

A

Which of the following properties is associated with a protein that will be secreted from a eukaryotic cell? A. Its signal sequence must target it to the ER, after which it goes to the Golgi. B. It must be translated by a ribosome that remains free within the cytosol. C. Its signal sequence must be cleaved off before the polypeptide can enter the ER. D. Its signal sequence must target it to the plasma membrane, where it causes exocytosis.

A

Which of the following statements about anabolic pathways is true? A. They consume energy to build up polymers from monomers. B. They are usually spontaneous chemical reactions. C. They decrease the entropy of the organism and its environment. D. They release energy by degrading polymers to monomers.

A

Which of the following statements correctly describes the difference between ATP and the nucleotides used during DNA synthesis? A. The nucleotides have the sugar deoxyribose; ATP has the sugar ribose. B. The nucleotides have two phosphate groups; ATP has three phosphate groups. C. ATP is found only in human cells; the nucleotides are found in all animal and plant cells. D. ATP contains three high-energy bonds; the nucleotides have two.

A

Which of the following statements defines a genome? A. the complete set of an organism's genes and other DNA sequences B. a karyotype C. the complete set of a species' polypeptides D. the complete set of an organism's polypeptides

A

Which of the following statements describes the events of apoptosis? A. The cell's DNA and organelles become fragmented, the cell shrinks and forms blebs, and the cell's parts are packaged in vesicles that are digested by specialized cells. B. The cell's DNA and organelles become fragmented, the cell dies, and it is phagocytized. C. The cell's nucleus and organelles are lysed, and then the cell enlarges and bursts. D. The cell dies, it is lysed, its organelles are phagocytized, and its contents are recycled.

A

Which of the following statements is true about protein synthesis in prokaryotes? A. Translation can begin while transcription is still in progress. B. Prokaryotic cells have complicated mechanisms for targeting proteins to the appropriate cellular organelles. C. Unlike eukaryotes, prokaryotes require no initiation or elongation factors. D. Extensive RNA processing is required before prokaryotic transcripts can be translated.

A

Which of the following statements is true for all exergonic reactions? A. The reaction proceeds with a net release of free energy. B. The products have more total energy than the reactants. C. A net input of energy from the surroundings is required for the reactions to proceed. D. The reaction goes only in a forward direction: all reactants will be converted to products, but no products will be converted to reactants.

A

Which of the following statements is true of a species that has a chromosome number of 2n = 16? A. Each diploid cell has eight homologous pairs of chromosomes. B. The species is diploid with 32 chromosomes per cell. C. A gamete from this species has four chromosomes. D. The species has 16 sets of chromosomes per cell.

A

Which of the following statements supports the argument that viruses are nonliving? A. They do not carry out metabolic processes. B. Their DNA does not encode proteins. C. They have RNA rather than DNA. D. They do not evolve.

A

Which of the following structures would decrease the electrochemical gradient across a membrane? A. a potassium channel B. an aquaporin C. a proton pump D. both a proton pump and a sodium channel

A

Which structure is common to plant and animal cells? A. mitochondrion B. chloroplast C. centriole D. central vacuole

A

Why are lipids and proteins free to move laterally in membranes? A. There are only weak hydrophobic interactions in the interior of the membrane. B. Hydrophilic portions of the lipids are in the interior of the membrane. C. The interior of the membrane is filled with liquid water. D. Lipids and proteins repulse each other in the membrane.

A

You disrupt all hydrogen bonds in a protein. What level of structure will be preserved? A. primary structure B. secondary structure C. tertiary structure D. quaternary structure

A

You would like to lose weight. Which of the following should be your preferred food group? A. Cellulose and fructose B. Starch and fructose C. Sucrose and starch D. Lactose and glucose

A

Zinc, an essential trace element for most organisms, is present in the active site of the enzyme carboxypeptidase. The zinc most likely functions as _____. A. a cofactor necessary for enzyme activity B. a noncompetitive inhibitor of the enzyme C. a coenzyme derived from a vitamin D. an allosteric activator of the enzyme

A

https://session.masteringbiology.com/problemAsset/2524907/1/urry11e_tb_05-02.jpg The molecule illustrated in the figure ________. A. will be liquid at room temperature B. is a saturated fatty acid C. is a carbohydrate D. stores genetic information

A

https://session.masteringbiology.com/problemAsset/2525150/1/urry11e_tb_10-04.jpg Halobacterium has a photosynthetic membrane that appears purple. Its photosynthetic action spectrum is the inverse of the action spectrum for green plants (see figure). That is, the Halobacterium action spectrum has a peak where the green plant action spectrum has a trough. What wavelengths of light do the Halobacterium photosynthetic pigments absorb? A. green and yellow B. violet and blue C. blue and red D. red and yellow

A

https://session.masteringbiology.com/problemAsset/2525394/1/urry11e_tb_14-06.jpg The following question refers to the pedigree chart in the figure for a family, some of whose members exhibit the dominant trait, W. Affected individuals are indicated by a dark square or circle. What is the probability that individual III-1 is Ww? A. 1 B. 3/4 C. 2/4 D. 1/4

A

https://session.masteringbiology.com/problemAsset/2525602/1/urry11e_tb_19-02.jpg In the figure, at the arrow marked II, what enzyme is being utilized? A. host cell DNA polymerase B. reverse transcriptase C. host cell RNA polymerase D. viral DNA polymerase

A

https://session.masteringbiology.com/problemAsset/2525603/1/urry11e_tb_19-02.jpg In the figure, when new viruses are being assembled at the point marked IV, what mediates the assembly? A. no mediator is required; the new viruses self-assemble B. assembly proteins coded for by the viral genes C. host cell chaperones D. assembly proteins coded for by the host nucleus

A

A bacterium engulfed by a white blood cell through phagocytosis will be digested by enzymes contained in _____. A. Golgi vesicles B. lysosomes C. vacuoles D. secretory vesicles

B

A carbon atom has 6 electrons however, its valency is 4. This is because the carbon atom ________. A. has 4 electrons in its first shell and 2 in the second shell B. has only 2 electrons in its first shell and 4 in the second shell C. donates its 2 electrons to another atom D. shares its 2 electrons and bonds with another atom

B

A newly discovered unicellular organism isolated from acidic mine drainage is found to contain a cell wall, a plasma membrane, two flagella, and peroxisomes. Based just on this information, the organism is most likely ________. A. a motile archaea B. a motile eukaryote C. a nonmotile prokaryote D. a nonmotile eukaryote E. a motile bacterium

B

A patient complaining of watery, itchy eyes and sneezing after being given a flower bouquet as a birthday gift should first be treated with _____. A. monoclonal antibodies B. antihistamines C. a vaccine D. sterile pollen

B

A researcher uses the chemical inhibitor cyanide to reduce ATP production in a neuron. What would be one effect of preventing ATP production? A. The membrane would become more permeable to sodium. B. Disruption to the normal "resting" distribution of potassium and sodium ions. C. The sodium and potassium channels would all be closed. D. A physical breakdown of the plasma membrane would occur.

B

A solution with a pH of 2 has how many more protons in it than a solution with a pH of 4? A. 10 times more B. 100 times more C. 1000 times more D. 5 times more

B

A young dog has never had much energy. He is brought to a veterinarian for help, and she decides to conduct several diagnostic tests. She discovers that the dog's mitochondria can use only fatty acids and amino acids for respiration, and his cells produce more lactate than normal. Of the following, which is the best explanation of the dog's condition? A. His cells lack the enzyme in glycolysis that forms pyruvate. B. His mitochondria lack the transport protein that moves pyruvate across the outer mitochondrial membrane. C. His cells have a defective electron transport chain, so glucose is metabolized to lactate instead of to acetyl CoA. D. His cells cannot move NADH from glycolysis into the mitochondria.

B

Analysis of a blood sample from a fasting individual who had not eaten for 24 hours would be expected to reveal high levels of ________. A. insulin B. glucagon C. glucose D. gastrin

B

As a research scientist, you measure the amount of ATP and NADPH consumed by the Calvin cycle in one hour. You find that 30,000 molecules of ATP were consumed, but only 20,000 molecules of NADPH were consumed. What is the source of the extra ATP molecules? A. linear electron flow B. cyclic electron flow C. photosystem I D. photosystem II

B

At which phase of the cell cycle do centrioles begin to move apart in animal cells? A. telophase B. prophase C. metaphase D. anaphase

B

Compared to oxidative skeletal muscle fibers, those classified as glycolytic typically have _____. A. a higher concentration of myoglobin B. less resistance to fatigue C. a higher density of mitochondria D. a smaller diameter

B

Cooking oil and gasoline (a hydrocarbon) are not amphipathic molecules because they _____. A. have hydrophobic and hydrophilic regions B. do not have a polar or charged region C. do not have a nonpolar region D. are highly reduced molecules

B

Cytosine makes up 42% of the nucleotides in a sample of DNA from an organism. Approximately what percentage of the nucleotides in this sample will be thymine? A. 58% B. 8% C. 42% D. 16%

B

During which phase of mitosis do the chromatids become chromosomes? A. prophase B. anaphase C. telophase D. metaphase

B

Hormone X activates the cAMP second messenger system in its target cells. The greatest response by a target cell would come from ________. A. applying a molecule of cAMP to the extracellular fluid surrounding the cell B. applying a molecule of hormone X to the extracellular fluid surrounding the cell C. injecting a molecule of hormone X into the cytoplasm of the cell D. injecting a molecule of activated, cAMP-dependent protein kinase into the cytoplasm of the cell

B

How many molecules of water are released during the polymerization of a 20 monomer-long cellulose molecule? A. 10 B. 19 C. 20 D. 40

B

If glucose is the sole energy source, what fraction of the carbon dioxide exhaled by animals is generated only by the reactions involved in oxidation of pyruvate to acetyl CoA? A. 2/3 B. 1/3 C. 1/6 D. all of it

B

In a humoral or antibody-mediated immune response, specific B cells are stimulated by helper T cells to transform into plasma cells that secrete antibodies. What would be an important feature added to the plasma cells during this transition process that allows them to better perform their function? A. duplication of lysosomes in order to store the antibodies before transport B. increased rough endoplasmic reticulum for greater antibody production C. duplication of specific gene sequences for the appropriate antibody D. increased antigen presentation on the surface of the plasma cells

B

In bacteria, there are 61 mRNA codons that specify an amino acid, but only 45 tRNAs. Which of the following statements explains this fact? A. Some tRNAs have anticodons that recognize four or more different codons. B. The rules for base pairing between the third base of a codon and tRNA are flexible. C. Many codons are never used, so the tRNAs that recognize them are dispensable. D. The DNA codes for all 61 tRNAs, but some are then destroyed.

B

In carbohydrates, the ratio of hydrogen (H) to oxygen (O) is ________. A. 1:1 B. 2:1 C. 3:1 D. 4:1

B

In cats, black fur color is determined by an X-linked allele; the other allele at this locus determines orange color. The heterozygote is tortoiseshell. What kinds of offspring would you expect from the cross of a black female and an orange male? A. black females; orange males B. tortoiseshell females; black males C. orange females; black males D. tortoiseshell females; tortoiseshell males

B

In chemiosmosis, what is the most direct source of energy that is used to convert ADP +Pi to ATP? A. energy released as electrons flow through the electron transport chain B. energy released from movement of protons through ATP synthase, down their electrochemical gradient C. energy released from substrate-level phosphorylation D. energy released as electrons are transported across the inner mitochondrial membrane

B

In mitochondria, an electron transport chain pumps protons from the matrix into the intermembrane space, whereas in chloroplasts, an electron transport chain pumps protons from the ________. A. matrix to the stroma B. stroma to the thylakoid space C. thylakoid space to the matrix D. thylakoid space to the stroma

B

In pea plants, the tall phenotype is dominant to the dwarf phenotype. If a heterozygous pea plant is crossed with a homozygous tall pea plant, what is the probability that the offspring will be dwarf in size? A. 1/2 B. 0 C. 1 D. 1/4

B

In presenting data that result from an experiment, a group of students show that most of their measurements fall on a straight diagonal line on their graph. However, two of their data points are "outliers" and fall far to one side of the expected relationship. What should they do? A. Average several trials, rule out the improbable results, and do not show them in the final work. B. Show all results obtained and then try to explore the reason(s) for these outliers. C. Do not show these points because clearly something went wrong in the experiment. D. Change the details of the experiment until they can obtain the expected results.

B

In sickle-cell disease, as a result of a single amino acid change, the mutant hemoglobin tetramers associate with each other and assemble into large fibers. Based on this information alone, we can conclude that sickle-cell hemoglobin exhibits ________. A. only altered tertiary structure B. altered primary structure and altered quaternary structure; the secondary and tertiary structures may or may not be altered C. only altered primary structure D. only altered quaternary structure

B

Ions can travel directly from the cytoplasm of one animal cell to the cytoplasm of an adjacent cell through _____. A. plasmodesmata B. gap junctions C. desmosomes D. tight junctions

B

Maltose is a disaccharide that can easily be digested into glucose molecules. The glycosidic linkage between glucose molecules in maltose is ________. A. β 14 B. α 14 C. α 12 D. β 12

B

Most cells cannot harness heat to perform work because _____. A. heat must remain constant during work B. temperature is usually uniform throughout a cell C. heat can never be used to do work D. heat is not a form of energy

B

P680+ is said to be the strongest biological oxidizing agent. Given its function, why is this necessary? A. It is the molecule that transfers electrons to plastoquinone (Pq) of the electron transfer system. B. It obtains electrons from the oxygen atom in a water molecule, so it must have a stronger attraction for electrons than oxygen has. C. It is the receptor for the most excited electron in either photosystem of photosynthesis. D. It transfers its electrons to reduce NADP+ to NADPH.

B

Proton pumps are used in various ways by members of every domain of organisms: Bacteria, Archaea, and Eukarya. What does this fact most probably mean? A. Cells of each domain evolved proton pumps independently when oceans became more acidic. B. Proton gradients across a membrane were used by cells that were the common ancestor of all three domains of life. C. The high concentration of protons in the ancient atmosphere must have necessitated a pump mechanism. D. Proton pumps are necessary to all cell membranes.

B

Skin color in a certain species of fish is inherited by a single gene with four different alleles. How many different types of gametes would be possible in this organism? A. 8 B. 4 C. 16 D. 2

B

Starch and cellulose ________. A. are cis and trans isomers of each other B. are polymers of glucose C. are structural components of the plant cell wall D. are used for energy storage in plants and animals

B

Students conducted an experiment to determine the effect of light intensity on the rate of photosynthesis. They punched 40 leaf disks from spinach leaves and used a syringe partially filled with water to pull the gases from the leaf disks so that all leaf disks sunk to the bottom of the syringe. Ten leaf disks from the syringe were placed in each of four cups and covered with 50 ml of the solutions as indicated below. All leaf disks were resting on the bottom of the cups when the experiment began. The volume of liquid in each cup and the temperature of the solutions were held constant. All cups were placed 0.5 meters from the designated light source. A large beaker of water was placed between the light and the cups to act as a heat sink to prevent a change in temperature. At the end of 10 minutes, the number of disks floating in each cup was recorded. Trial Grams of baking soda (CO2 source) Wattage of light bulb Disks floating at 10 minutes 1 0.5 25 3 2 0.5 50 5 3 0.5 75 9 4 0 75 0 Use your knowledge of the mechanism of photosynthesis and the data presented in the chart to determine which of the statements is a correct explanation for the students' data. A. Cup 3 had the same rate of photosynthesis as Cup 1 because they had the same ratio of disks floating to wattage of light. B. Cup 4 had the lowest rate of photosynthesis because it had the least CO2. C. Cup 2 had the highest rate of photosynthesis because it had the highest ratio of disks floating to wattage of light. D. Cup 1 had a low rate of photosynthesis because 0.5 grams of baking soda did not provide a sufficient amount of CO2.

B

Suppose you are provided with an actively dividing culture of E. coli bacteria to which radioactive thymine has been added. What would happen if a cell replicates once in the presence of this radioactive base? A. One of the daughter cells, but not the other, would have radioactive DNA. B. DNA in both daughter cells would be radioactive. C. All four bases of the DNA would be radioactive. D. Neither of the two daughter cells would be radioactive.

B

The host range of a virus is determined by _____. A. whether its nucleic acid is DNA or RNA B. the proteins on its surface and that of the host C. the enzymes carried by the virus D. the proteins in the host's cytoplasm

B

The membranes of winter wheat are able to remain fluid when it is extremely cold by ________. A. increasing the proportion of glycolipids in the membrane B. increasing the proportion of unsaturated phospholipids in the membrane C. decreasing the percentage of cholesterol molecules in the membrane D. decreasing the number of hydrophobic proteins in the membrane

B

The molecular formula for glucose is C6H12O6. What would be the molecular formula for a molecule made by linking three glucose molecules together by dehydration reactions? A. C6H10O5 B. C18H32O16 C. C18H36O18 D. C18H30O15

B

The nuclear lamina is an array of intermediate filaments that line the inner side of the nuclear membrane. If a chemical treatment caused the lamina to disassemble, what would you expect to be the most likely immediate consequence? A. a loss of genetic information from chromosomes B. a change in the shape of the nucleus C. closing of nuclear pores D. the inability of the nucleus to divide during cell division

B

The predatory bacterium Bdellovibrio bacteriophorus drills into a prey bacterium and, once inside, digests it. In an attack upon a gram-negative bacterium that has a slimy cell covering, what is the correct sequence of structures penetrated by B. bacteriophorus on its way to the prey's cytoplasm? A. lipopolysaccharide membrane, peptidoglycan, capsule, phospholipid membrane B. capsule, lipopolysaccharide membrane, peptidoglycan, phospholipid membrane C. phospholipid membrane, capsule, peptidoglycan, lipopolysaccharide membrane D. lipopolysaccharide membrane, capsule, peptidoglycan, phospholipid membrane

B

The solutions in the two arms of this U-tube are separated by a membrane that is permeable to water and glucose but not to sucrose. Side A is half-filled with a solution of 2 M sucrose and 1 M glucose. Side B is half-filled with 1 M sucrose and 2 M glucose. Initially, the liquid levels on both sides are equal. A U-shaped tube is shown with the water-permeable membrane at the center of the bottom of the U. The left side, labeled A, is filled with a mixture of 2 M sucrose and 1 M glucose. The right side, labeled B, is filled with a mixture of 1 M sucrose and 2 M. glucose. The two sides of the tube are level with each other. When the system illustrated above reaches equilibrium, the sugar concentrations on both sides of the U-tube will be ________. A. 2 M sucrose, 1 M glucose B. 1.5 M sucrose, 1.5 M glucose C. 1 M sucrose, 1 M glucose D. 1 M sucrose, 2 M glucose

B

The steroid hormone aldosterone affects only a small number of cells in the body because ________. A. nontarget cells destroy aldosterone before it can produce any effect B. only target cells contain aldosterone receptors C. aldosterone is unable to enter nontarget cells D. only target cells are exposed to aldosterone

B

The three stages of information processing in animals include ________. A. chemical senses, mechanoreception, and vision B. sensory reception, an integrating center, and effectors (motor neurons) C. dendrites, a cell body, and an axon D. a presynaptic cell, neurotransmitters, and a postsynaptic cell

B

To identify the molecule that accepts CO2, Calvin and Benson manipulated the carbon-fixation cycle by either cutting off CO2 or cutting off light from cultures of photosynthetic algae. They then measured the concentrations of various metabolites immediately following the manipulation. How would these experiments help identify the CO2 acceptor? A. The CO2 acceptor concentration would increase when either the CO2 or light are cut off. B. The CO2 acceptor concentration would increase when the CO2 is cut off, but decrease when the light is cut off. C. The CO2 acceptor concentration would decrease when either the CO2 or light are cut off. D. The CO2 acceptor concentration would decrease when the CO2 is cut off, but increase when the light is cut off.

B

Transcription in eukaryotes requires which of the following molecules in addition to RNA polymerase? A. ribosomes and tRNA B. several transcription factors C. anticodons D. aminoacyl-tRNA synthetase

B

Use the following information to answer the question(s) below. An otherwise healthy student in your class was infected with EBV (the virus that causes infectious mononucleosis) when she was a child, at which time she had merely experienced a mild sore throat and swollen lymph nodes in her neck. When she is exposed to EBV again later in life, she does not get sick or have any symptoms of mononucleosis. Which of the following statements explains why your class mate does not exhibit symptoms of EBV infection? A. Her innate immune response was better at recognizing the EBV antigen during the second infection. B. Memory T cells quickly recognized the virus upon the second exposure and destroyed the virally infected cells. C. She was likely infected with a weaker strain of EBV during her second exposure. D. Complement proteins effectively controlled the EBV during the second infection.

B

Use the following information to answer the question. "The native structure of hemoglobin (Hb) comprises of two α and two β subunits, each of which carries a heme group. There appear to be no previous studies that report the in-vitro folding and assembly of Hb from highly unfolded α and β globin in a 'one-pot' reaction. One difficulty that has to be overcome for studies of this kind is the tendency of Hb to aggregate during refolding. This work demonstrates that denaturation of Hb in 40% acetonitrile at pH 10.0 is reversible." (J Am Soc Mass Spectrum 2007, 18, 8-16) How many heme groups are present in three hemoglobin protein molecules? A. 9 B. 12 C. 3 D. 4

B

Use the information in the following paragraph to answer the question(s) below. A hypothetical bacterium swims among human intestinal contents until it finds a suitable location on the intestinal lining. It adheres to the intestinal lining using a feature that also protects it from phagocytes, bacteriophages, and dehydration. Fecal matter from a human in whose intestine this bacterium lives can spread the bacterium, even after being mixed with water and boiled. The bacterium is not susceptible to the penicillin family of antibiotics. It contains no plasmids and relatively little peptidoglycan. Adherence to the intestinal lining by this bacterium is due to its possession of _____. A. pili B. a capsule C. a flagellum D. fimbriae

B

Water has many exceptional and useful properties. Which is the rarest property among compounds? A. Water has surface tension. B. Solid water is less dense than liquid water. C. Water is a solvent. D. Water has a high heat capacity.

B

What are the products of cyclic electron flow during the light reactions of photosynthesis? A. ATP and NADPH B. ATP C. ADP and NADP+ D. heat and fluorescence

B

What is the name of the thermodynamic barrier that must be overcome before products are formed in a spontaneous reaction? A. free energy B. activation energy C. entropy D. the equilibrium point

B

What makes lipids/fats hydrophobic? A. the carboxyl group at one end of the molecule B. presence of relatively nonpolar CH bonds C. their long carbon skeleton D. the glycerol moiety

B

Where are proteins produced other than on ribosomes free in the cytosol or ribosomes attached to the endoplasmic reticulum? A. in the Golgi apparatus B. in mitochondria C. in lysosomes D. in the nucleolus

B

Which of the following conditions may be overcome by increasing the substrate concentration in an enzymatic reaction with a fixed amount of enzyme? A. the need for a coenzyme B. competitive inhibition C. allosteric inhibition D. noncompetitive inhibition

B

Which of the following correctly describes chemical equilibrium? A. There are equal concentrations of products and reactants while forward and reverse reactions continue. B. Forward and reverse reactions continue with no net effect on the concentrations of the reactants and products. C. Concentrations of products are higher than the concentrations of the reactants. D. There are equal concentrations of reactants and products, and the reactions have stopped.

B

Which of the following illustrations is not a structural isomer of an organic compound with the molecular formula C6H14? For clarity, only the carbon skeletons are shown; hydrogen atoms that would be attached to the carbons have been omitted. A. A chain of five carbons with a sixth carbon bonded below the middle carbon of the chain. B. Two carbons are double-bonded to each other. More carbons are single-bonded to the left and below the left-hand carbon and to the right and below the right-hand carbon. C. A chain of four carbons. Additional carbons are bonded above and below the third carbon in the chain. D. A chain of five carbon atoms with a sixth carbon bonded below the second carbon from the end of the chain.

B

Which of the following observations about flagella is accurate and is consistent with the scientific conclusion that the flagella from eukaryotes and bacteria evolved independently? A. Although the mechanism of movement in both flagella is the same, the protein that accomplishes the movement is different. B. The protein structure and the mechanism of movement in eukaryotes flagella are different from those of bacteria flagella. C. The mechanics of movement and protein structure are the same in these flagella, but there are significant genetic differences. D. The flagella of both eukaryotes and bacteria are made of the same protein, but the configuration is different.

B

Which of the following processes includes all of the others? A. transport of an ion down its electrochemical gradient B. passive transport C. facilitated diffusion D. osmosis

B

Which of the following processes occurs in a plant's sexual life cycle? A. sporophytes produce gametes by mitosis B. gametophytes produce gametes by mitosis C. sporophytes produce gametes by meiosis D. gametophytes produce gametes by meiosis

B

Which of the following processes occurs in prokaryotes but not in eukaryotes? A. translation in the absence of a ribosome B. transcription and translation occur simultaneously C. gene splicing D. post-transcriptional splicing

B

Which of the following question is considered a thought-provoking scientific query? A. How long ago did the Pterosaurs live on this planet? B. How many tigers are left in India? C. Does the amount of solute in water affect the boiling point of the solution? D. Who invented the telescope?

B

Which of the following statements accurately describes the differences between DNA replication in prokaryotes and DNA replication in eukaryotes? A. Prokaryotic chromosomes have histones, whereas eukaryotic chromosomes do not. B. Prokaryotic chromosomes have a single origin of replication, whereas eukaryotic chromosomes have many. C. Prokaryotes produce Okazaki fragments during DNA replication, but eukaryotes do not. D. The rate of elongation during DNA replication is slower in prokaryotes than in eukaryotes.

B

Which of the following statements correctly describes a difference between viruses and prions? A. Viruses have genomes composed of RNA, whereas prions have genomes composed of DNA. B. Viruses generally cause disease symptoms quickly, whereas prions generally take many years to cause disease symptoms. C. Viruses infect many types of cells, whereas prions infect only prokaryotic cells. D. Viruses have capsids composed of protein, whereas prions are made only of nucleic acid.

B

Which of the following statements correctly describes vaccines and how they help prevent viral infection? A. Vaccines are infectious proteins that stimulate an immune reaction in a person. B. Vaccines are inactive versions of a virus that stimulate an immune reaction in a person. C. Vaccines are active versions of a virus that stimulate an immune reaction in a person. D. Vaccines are infectious enzymes that stimulate an immune reaction in a person.

B

Which of the following statements describes a characteristic feature of a carrier protein in a plasma membrane? A. It works against diffusion. B. It exhibits specificity for a particular type of molecule. C. It has no hydrophobic regions. D. It requires the expenditure of cellular energy to function.

B

Which one of the following conditions would allow gene frequencies to change by chance? A. mutation B. small populations C. large population D. gene flow

B

Which polysaccharide is an important component in the structure of many animals and fungi? A. amylopectin B. chitin C. amylose D. cellulose

B

Which two functional groups are always found in amino acids? A. carbonyl and amino groups B. carboxyl and amino groups C. hydroxyl and carboxyl groups D. amino and sulfhydryl groups

B

Why are carbohydrates and fats frequently considered high-energy foods? A. They contain no nitrogen atoms. B. They contain many electrons associated with hydrogen atoms. C. They contain many oxygen atoms. D. They are strong oxidizing molecules.

B

You are suffering from Streptococcus throat infection. You share the following with the bacteria that is responsible for your condition. A. You both belong to the same domain. B. You both are made up of cells. C. You and Streptococcus have nothing in common. D. You both have genetic material in your nucleus.

B

https://session.masteringbiology.com/problemAsset/2524933/3/urry11e_tb_05-05.jpg A fat (or triacylglycerol) would be formed as a result of a dehydration reaction between ________. A. one molecule of 9 and three molecules of 10 B. three molecules of 9 and one molecule of 10 C. one molecule of 5 and three molecules of 9 D. one molecule of 5 and three molecules of 10

B

https://session.masteringbiology.com/problemAsset/2525145/1/urry11e_tb_10-03.jpg What wavelength of light in the figure is most effective in driving photosynthesis? A. 730 nm B. 420 nm C. 575 nm D. 625 nm

B

https://session.masteringbiology.com/problemAsset/2525497/1/urry11e_tb_17-02.jpg Refer to the metabolic pathway illustrated. If A, B, and C are all required for growth, a strain that is mutant for the gene-encoding enzyme A would be able to grow on medium supplemented with which of the following nutrient(s)? A. nutrient C only B. either nutrient B or C C. nutrients A and C D. nutrient A only

B

https://session.masteringbiology.com/problemAsset/2525592/1/urry11e_tb_19-01.jpg Which of the three types of viruses shown would you expect to include glycoproteins? A. I only B. II only C. III only D. I and II only

B

A cell with a predominance of smooth endoplasmic reticulum is likely specialized to ________. A. store large quantities of water B. import and export large quantities of protein C. synthesize large quantities of lipids D. actively secrete large quantities of protein

C

A decrease in entropy is associated with which type of reaction? A. hydrolysis B. catabolic C. dehydration D. depolymerization

C

A number of systems for pumping ions across membranes are powered by ATP. Such ATP-powered pumps are often called ATPases, although they do not often hydrolyze ATP unless they are simultaneously transporting ions. Because small increases in calcium ions in the cytosol can trigger a number of different intracellular reactions, cells keep the cytosolic calcium concentration quite low under normal conditions, using ATP-powered calcium pumps. For example, muscle cells transport calcium from the cytosol into the membranous system called the sarcoplasmic reticulum (SR). If a resting muscle cell's cytosol has a free calcium ion concentration of 10-7 while the concentration in the SR is 10-2, then how is the ATPase acting? A. ATPase activity must be opening a channel for the calcium ions to diffuse back into the SR along the concentration gradient. B. ATPase activity must be transferring Pi to the SR to enable this to occur. C. ATPase activity must be pumping calcium from the cytosol to the SR against the concentration gradient. D. ATPase activity must be powering an inflow of calcium from the outside of the cell into the SR.

C

A strain of fruit fly lacks the ability to produce Dicer-2 protein. You might expect this strain to be more susceptible to ________ infections. A. protozoan B. fungal C. viral D. bacterial

C

Accuracy in the translation of mRNA into the primary structure of a polypeptide depends on specificity in the _____. A. binding of ribosomes to mRNA B. binding of the anticodon to small subunit of the ribosome C. binding of the anticodon to the codon and the attachment of amino acids to tRNAs D. attachment of amino acids to rRNAs

C

An immunoglobulin (Ig) molecule, of any class, with regions symbolized as C or V, H or L, has a light chain made up of ________. A. three H regions and one L region B. one H region and one L region C. one C region and one V region D. two C regions and two V regions

C

Besides the ability of some cancer cells to over proliferate, which of the following situations might logically result in a tumor? A. changes in the order of cell cycle stages B. inability to form spindles C. lack of appropriate cell death D. failure of cells to enter S phase

C

During a laboratory experiment, you discover that an enzyme-catalyzed reaction has a G of -20 kcal/mol. If you double the amount of enzyme in the reaction, what will be the ∆G for the new reaction? A. -10 kcal/mol B. -40 kcal/mol C. -20 kcal/mol D. +20 kcal/mol

C

During aerobic respiration, which of the following molecules directly donates electrons to the electron transport chain at the lowest energy level? A. NADH B. water C. FADH2 D. ATP

C

During the elongation phase of translation, which site in the ribosome represents the location where a codon is being read? A. E site B. P site C. A site D. the large ribosomal subunit

C

Feather color in budgies is determined by two different genes, Y for pigment on the outside of the feather, and B for pigment on the inside of the feather. YYBB, YyBB, or YYBb is green; yyBB or yyBb is blue; YYbb or Yybb is yellow; and yybb is white. Two blue budgies were crossed. Over the years, they produced 22 offspring, five of which were white. What are the most likely genotypes for the two blue budgies? A. yyBB and yyBb B. yyBB and yyBB C. yyBb and yyBb D. yyBb and yybb

C

Following glycolysis and the citric acid cycle, but before the electron transport chain and oxidative phosphorylation, the carbon skeleton of glucose has been broken down to CO2 with some net gain of ATP. Most of the energy from the original glucose molecule at that point in the process, however, is stored in the form of which of the following molecules? A. NAD+ B. pyruvate C. NADH D. acetyl-CoA

C

For the following question, match the labeled component of the cell membrane in the figure with its description. The figure shows a fragment of the cell. Label A is a fiber outside the cell, label B is a glycolipid, label C is a fiber in the cytoplasm, label D is a molecule on the internal surface of the membrane, and label E is a fat molecule bound into the membrane, which is a characteristic of animal cells. Which component in the accompanying figure is a microfilament (actin filament) of the cytoskeleton? A B C D

C

Given the following genotypes for two parents, AABBCc × AabbCc, assume that all traits exhibit simple dominance and independent assortment. What proportion of the progeny of this cross will be expected to phenotypically resemble the first parent with the genotype AABBCc? A. 1 B. 1/4 C. 3/4 D. 3/8

C

Hershey and Chase used a DNA-based virus for their work. How might the results have been different if they had used an RNA virus? A. With an RNA virus, neither sample would have had a radioactive pellet. B. With an RNA virus, the protein shell would have been radioactive in both samples. C. With an RNA virus, radioactive RNA would have been in the final pellet. D. With an RNA virus, radioactive protein would have been in the final pellet.

C

How does natural selection apply to sexual reproduction as opposed to asexual reproduction? A. Sexual reproduction results in the greatest number of new mutations. B. Sexual reproduction utilizes far less energy than asexual reproduction. C. Sexual reproduction results in many new gene combinations, some of which will lead to differential reproduction. D. Sexual reproduction allows the greatest number of offspring to be produced.

C

If photosynthesizing green algae are provided with CO2 containing heavy oxygen (18O), which of the following molecules produced by the algae (refer to the accompanying figure) will fail to contain 18O in later biochemical analyses? A. ribulose bisphosphate (RuBP) B. glyceraldehyde 3-phosphate (G3P) C. ADP D. 3-phosphoglycerate

C

In birds, sex is determined by a ZW chromosome scheme. Males are ZZ and females are ZW. A recessive lethal allele that causes death of the embryo is sometimes present on the Z chromosome in pigeons. What would be the sex ratio in the offspring of a cross between a male that is heterozygous for the lethal allele and a normal female? A. 3:1 male to female B. 1:2 male to female C. 2:1 male to female D. 1:1 male to female

C

In comparison to eukaryotes, prokaryotes _____. A. are more structurally complex B. are larger C. are smaller D. do not have membranes

C

In some cells, there are many ion electrochemical gradients across the plasma membrane even though there are usually only one or two proton pumps present in the membrane. The gradients of the other ions are most likely accounted for by _____. A. passive diffusion across the plasma membrane B. pores in the plasma membrane C. cotransport proteins D. ion channels

C

Inheritance patterns cannot always be explained by Mendel's models of inheritance. If a pair of homologous chromosomes fails to separate during meiosis I, select the choice that shows the chromosome number of the four resulting gametes with respect to the normal haploid number (n)? A. n + 1; n - 1; n; n B. n + 1; n + 1; n; n C. n + 1; n + 1; n - 1; n - 1 D. n + 1; n - 1; n - 1; n - 1

C

Living organisms increase in complexity as they grow, resulting in a decrease in the entropy of an organism. How does this relate to the second law of thermodynamics? A. Living organisms do not obey the second law of thermodynamics, which states that the entropy of an organism increases with each energy transformation. B. As a consequence of growth, the decrease in entropy of the organism is associated with a corresponding decrease in the entropy of the universe. C. The decrease in entropy is associated with growth of an organism. As a consequence of growth, organisms cause a greater increase in entropy in their environment than the decrease in entropy associated with their increased complexity. D. Living organisms are able to transform chemical energy into entropy.

C

Marfan syndrome in humans is caused by an abnormality of the connective tissue protein fibrillin. Patients are usually very tall and thin, with long spindly fingers, curvature of the spine, sometimes weakened arterial walls, and sometimes eye problems, such as lens dislocation. Which of the following would you conclude about Marfan syndrome from this information? A. It is dominant. B. It is epistatic. C. It is pleiotropic. D. It is recessive.

C

Miller's classic experiment demonstrated that a discharge of sparks through a mixture of gases could result in the formation of a large variety of organic compounds. Miller did not use ________ as one of the gases in his experiment. A. water B. ammonia C. oxygen D. methane

C

Most of the ATP supplies for a skeletal muscle undergoing one hour of sustained exercise come from _____. A. glycolysis B. creatine phosphate C. oxidative phosphorylation D. substrate phosphorylation

C

Once a cell enters mitosis, the molecules that activate division must be turned off. What happens to MPF during mitosis? A. It is phosphorylated by a Cdk, which inactivates it. B. The Cdk component of MPF is degraded. C. The cyclin component of MPF is degraded. D. It is completely degraded.

C

Opening all of the sodium channels on an otherwise typical neuron, with all other ion channels closed (which is an admittedly artificial setting), should move its membrane potential to ________. A. 0 mV B. -90 mV C. equilibrium potential for sodium D. The membrane potential would not change, only the ion concentrations would change.

C

Particular receptor tyrosine kinases (RTKs) that promote excessive cell division are found at high levels in various cancer cells. HER2 is an RTK that is present at excessively high levels in some breast cancer cells. Herceptin is a protein that binds to HER2 and inhibits cell division. Herceptin may be an effective treatment for breast cancer treatment under which of the following conditions? A. If injection of HER2 in the patient's cancer cells stimulates cell division. B. If the patient's genome codes for the HER2. C. If the patient's cancer cells have excessive levels of HER2. D. If the patient has excessive levels of other RTKs in cancer cells.

C

Poliovirus is an RNA virus of the picornavirus group, which uses its RNA as mRNA. At its 5 end, the RNA genome has a viral protein (VPg) instead of a 5 cap. This is followed by a non-translated leader sequence, and then a single long protein-coding region (~7,000 nucleotides), followed by a poly-A tail. Observations were made that used radioactive amino acids similar in structure to those that are found in viruses and other organisms. Short-period use of the radioactive amino acids result in labeling of only very long proteins, while longer periods of labeling result in several different short polypeptides. What conclusion is most consistent with the results of the radioactive labeling experiment? A. The large radioactive polypeptides are coded by the host, whereas the short ones are coded for by the virus. B. Host cell ribosomes only translate the viral code into short polypeptides. C. The RNA is only translated into a single long polypeptide, which is then cleaved into shorter ones. D. The RNA is translated into short polypeptides, which are subsequently assembled into large ones.

C

Radish flowers may be red, purple, or white. A cross between a red-flowered plant and a white-flowered plant yields all-purple offspring. The part of the radish we eat may be oval or long, with long being the dominant trait. If true-breeding red long radishes are crossed with true-breeding white oval radishes, the F1 will be expected to exhibit which of the following phenotypes? A. purple and oval B. white and long C. purple and long D. red and long

C

Scientists have found that extracellular matrix components may induce specific gene expression in embryonic tissues such as the liver and testes. For this to happen, there must be direct communication between the extracellular matrix and the developing cells. Which kind of transmembrane protein would most likely be involved in this kind of induction? A. fibronectins B. actin microfilaments C. integrins D. receptor tyrosine kinases

C

Tay-Sachs disease is a human genetic abnormality that results in cells accumulating and becoming clogged with very large, complex, undigested lipids. Which cellular organelle is most likely defective in this condition? A. the Golgi apparatus B. the smooth endoplasmic reticulum C. the lysosome D. the rough endoplasmic reticulum

C

The application of scientific knowledge for some specific purpose is known as _____. A. inductive science B. pure science C. technology D. deductive science

C

The atomic number of chlorine is 17. The atomic number of magnesium is 12. What is the formula for magnesium chloride? A. Mg2Cl B. MgCl C. MgCl2 D. MgCl3

C

The cell walls of bacteria, fungi, and plant cells, and the extracellular matrix of animal cells are all external to the plasma membrane. Which of the following characteristics are common to all of these extracellular structures? A. They must provide a rigid structure that maintains an appropriate ratio of cell surface area to volume. B. They must block water and small molecules to regulate the exchange of matter and energy with their environment. C. They are constructed of materials that are synthesized in the cytoplasm and then transported out of the cell for assembly. D. They are composed of a mixture of lipids and nucleotides.

C

The cities of Portland, Oregon, and Minneapolis, Minnesota, are at about the same latitude, but Minneapolis has much hotter summers and much colder winters than Portland. Why? A. They are not at the same exact latitude. B. Minneapolis is much windier, due to its location in the middle of North America. C. The ocean near Portland moderates the temperature. D. Fresh water is more likely to freeze than salt water.

C

The enzyme phosphofructokinase (PFK) catalyzes a key step in glycolysis. PFK is inhibited by high levels of which of the following molecules? A. glucose and NAD+ B. citrate and CO2 C. ATP and citrate D. AMP and ATP

C

The eyes and the respiratory tract are both protected against infections by _____. A. the release of slightly alkaline secretions B. interferons produced by immune cells C. the secretion of lysozyme onto their surfaces D. the secretion of complement proteins

C

The genetic code is essentially the same for all organisms. From this, one can logically assume which of the following statements to be true? A. Different organisms have different types of amino acids. B. DNA was the first genetic material. C. A gene from an organism can theoretically be expressed by any other organism. D. The same codons in different organisms translate into different amino acids.

C

The most commonly occurring mutation in people with cystic fibrosis is a deletion of a single codon. What is the result of this type of mutation? A. a nonsense mutation B. a frameshift mutation C. a polypeptide missing an amino acid D. a base-pair substitution

C

The partial negative charge at one end of a water molecule is attracted to the partial positive charge of another water molecule. What is this attraction called? A. a covalent bond B. an ionic bond C. a hydrogen bond D. a van der Waals interaction

C

The relation between amino acid and polypeptide is similar to the relation between ________. A. triglycerides and steroids B. glycogen and glucose C. nucleotide and nucleic acid D. phospholipid and plasma membrane

C

The solutions in the arms of a U-tube are separated at the bottom of the tube by a selectively permeable membrane. The membrane is permeable to sodium chloride but not to glucose. Side A is filled with a solution of 0.4 M glucose and 0.5 M sodium chloride (NaCl), and side B is filled with a solution containing 0.8 M glucose and 0.4 M sodium chloride. Initially, the volume in both arms is the same. A U-shaped tube is shown with the water-permeable membrane at the center of the bottom of the U. The left side, labeled A, is filled with a mixture of 0.4 M glucose and 0.5 M sodium chloride (NaCl). The right side, labeled B, is filled with a mixture of 0.8 M glucose and 0.4 M sodium chloride. The two sides of the tube are level with each other. In the U-tube experiment illustrated above, which of the following statements correctly describes side B at equilibrium? A. The concentration of NaCl will increase, the concentration of glucose will decrease, and the water level will decrease. B. The concentration of NaCl and glucose will increase, and the water level will decrease. C. The concentration of NaCl will increase, the concentration of glucose will decrease, and the water level will increase. D. The concentration of NaCl and glucose will decrease, and the water level will increase.

C

The temperature at which an alligator's egg is incubated will determine the sex of the offspring. The dependent and the independent variables in this experiment are ________. A. size of the incubator and size of the baby alligator respectively B. temperature and sex of the baby alligator respectively C. sex of the baby alligator and temperature respectively D. number of offspring and temperature in the incubator respectively

C

Vertebrate immune cells, which are phagocytic, include ________. I) neutrophils II) macrophages III) dendritic cells IV) natural killer cells A. II and IV B. I and III C. I, II, and III D. I and IV

C

What happens when electrons are passed from one atom to a more electronegative atom? A. The more electronegative atom is oxidized, and energy is consumed. B. The more electronegative atom is reduced, and energy is consumed. C. The more electronegative atom is reduced, and energy is released. D. The more electronegative atom is oxidized, and energy is released.

C

What is the explanation for how a modern transmission electron microscope (TEM) can achieve a resolution of about 0.2 nanometers, whereas a standard light microscope has a maximum resolution of about 200 nanometers? A. Glass lenses in light microscopes refract light, which reduces resolution. B. The electron microscope has a much greater ratio of image size to real size. C. Electron beams have much shorter wavelengths than visible light. D. Contrast is enhanced by staining with atoms of heavy metal.

C

What is the function of the enzyme topoisomerase in DNA replication? A. elongating new DNA at a replication fork by adding nucleotides to the existing chain B. reattaching the hydrogen bonds between the base pairs in the double helix C. relieving strain in the DNA ahead of the replication fork caused by the untwisting of the double helix D. building RNA primers using the parental DNA strand as a template

C

Where in a plant cell does the Calvin cycle take place? A. interior of the thylakoid (thylakoid space) B. thylakoid membrane C. stroma of the chloroplast D. outer membrane of the chloroplast

C

Which molecule has both hydrophilic and hydrophobic properties and is found in plasma membranes? A. 12 B. 1 C. 5 D. 14

C

Which of the following characteristics do homologous chromosomes exhibit? A. They align on the metaphase plate in meiosis II. B. They carry information for different traits. C. They carry information for the same traits. D. They carry the same alleles.

C

Which of the following descriptions correctly identifies the main structural differences between viruses with envelopes and viruses without envelopes? A. Both types of viruses have a capsid and phospholipid membrane; but in the viruses without envelopes, the genetic material is between these two membranes, while in the viruses with envelopes the genetic material is inside both membranes. B. Viruses with envelopes have their genetic material enclosed by a layer made only of protein. C. Viruses with envelopes have a phospholipid membrane outside their capsid, whereas viruses without envelopes do not have a phospholipid membrane. D. Viruses without envelopes have only a phospholipid membrane, while viruses with envelopes have two membranes, the other one being a protein capsid.

C

Which of the following events are associated with chemiosmosis in chloroplasts? A. The pH of the stroma increases and ATP is synthesized. B. The pH of the cytoplasm outside the chloroplast decreases and ATP is synthesized. C. The pH of the thylakoid space increases and ATP is synthesized. D. The pH of the stroma decreases and ATP is hydrolyzed.

C

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

C

Which of the following graphs describes the relationship between [H3O+] and pH? A. Four graphs in A-D, each with [H3O+] for the Y axis and pH for the X axis. B) A line begins at origin, rises slowly, and then curves to rise steeply. B. Four graphs in A-D, each with [H3O+] for the Y axis and pH for the X axis. C) A line begins at origin, rises steeply, then curves to level off. C. Four graphs in A-D, each with [H3O+] for the Y axis and pH for the X axis. D) A line begins high on the Y axis, drops sharply, then curves to approach the X axis. D. Four graphs in A-D, each with [H3O+] for the Y axis and pH for the X axis. A) A line begins at the origin and rises at a steady pace.

C

Which of the following is the most common pathway taken by a newly synthesized protein that will be secreted by a cell? A. Golgi → rough ER → lysosome → transport vesicle → plasma membrane B. rough ER → lysosome → transport vesicle → plasma membrane C. rough ER → Golgi → transport vesicle → plasma membrane D. rough ER → Golgi → transport vesicle → nucleus

C

Which of the following lists represents the order of increasingly higher levels of organization of chromatin? A. looped domain, 30-nm chromatin fiber, nucleosome B. 30-nm chromatin fiber, nucleosome, looped domain C. nucleosome, 30-nm chromatin fiber, looped domain D. nucleosome, looped domain, 30-nm chromatin fiber

C

Which of the following macromolecules enter the nucleus of a eukaryotic cell through pores in the nuclear membrane? A. phospholipids B. rRNA C. ribosomal proteins D. mRNA

C

Which of the following molecular characteristics cause histones to bind tightly to DNA? A. Histones are covalently linked to the DNA. B. Histones are negatively charged, and DNA is positively charged. C. Histones are positively charged, and DNA is negatively charged. D. Both histones and DNA are strongly hydrophobic.

C

Which of the following order is correct in terms of the hierarchy of the organization? A. Ecosystem → Community → Biosphere → Population → Organism B. Biosphere → Ecosystem → Population → Community → Organism C. Biosphere → Ecosystem →Community → Population → Organism D. Ecosystem → Biosphere → Population → Community → Organism

C

Which of the following organelles produces and modifies polysaccharides that will be secreted? A. lysosome B. peroxisome C. Golgi apparatus D. mitochondrion

C

Which of the following processes correctly describes alternative RNA splicing? A. It increases the rate of transcription. B. It can allow the production of similar proteins from different RNAs. C. It can allow the production of proteins of different sizes and functions from a single mRNA. D. It is a mechanism for increasing the rate of translation.

C

Which of the following processes occurs during the Calvin cycle? A. production of ATP B. reduction of NADPH C. regeneration of the CO2 acceptor D. release of oxygen

C

Which of the following processes would be most directly affected if a thylakoid membrane is punctured so that the interior of the thylakoid is no longer separated from the stroma? A. splitting of water B. reduction of NADP+ C. synthesis of ATP D. flow of electrons from photosystem II to photosystem I

C

Which of the following properties is associated with a cyclin-dependent kinase (Cdk)? A. The number of Cdk molecules increases during the S and G2 phases and decrease during M. B. A Cdk is inactive, or "turned off," in the presence of a cyclin. C. A Cdk is an enzyme that attaches phosphate groups to other proteins. D. A Cdk is an enzyme that catalyzes the attachment of kinetochores to microtubules.

C

Which of the following statements about a G protein signaling pathway is true? A. A G protein-coupled receptor bound to GTP is in its active state. B. A G protein bound to GDP is in its active state. C. A G protein bound to GTP is in its active state. D. Hydrolysis of bound GTP by a G protein activates the G protein.

C

Which of the following statements about independent assortment or segregation is correct? A. The law of segregation describes the behavior of two or more genes relative to one another. B. The law of segregation is accounted for by anaphase of mitosis. C. The law of independent assortment describes the behavior of two or more genes relative to one another. D. The law of independent assortment is accounted for by observations of prophase I of meiosis.

C

Which of the following statements about the electron transport chain is true? A. It is driven by ATP hydrolysis. B. It occurs in the cytoplasm of both prokaryotic and eukaryotic cells. C. It consists of a series of redox reactions D. It includes a series of hydrolysis reactions associated with mitochondrial membranes.

C

Which of the following statements about the evolution of life on Earth, from simple prokaryote-like cells to multicellular eukaryotic organisms, is true? A. It has occurred in accordance with the laws of thermodynamics and resulted in a substantial increase in the entropy of the planet. B. It has occurred in accordance with the laws of thermodynamics and resulted in a substantial increase in the total energy in the universe. C. It has occurred in accordance with the laws of thermodynamics and resulted in a substantial decrease in the entropy of the planet. D. By resulting in such diversity and complexity of life, it is an exception to the second law of thermodynamics.

C

Which of the following statements are fundamental to the clonal-selection theory of how the adaptive immune system functions? I) Each lymphocyte has a unique membrane receptor that recognizes one antigen. II) When the lymphocyte binds an antigen, it is activated and begins dividing to form many identical copies of itself. III) Cloned lymphocytes have slight differences and are selected by the spleen for removal if they do not bind an antigen. IV) Cloned cells descend from an activated lymphocyte and persist even after the pathogen is eliminated. A. only II, III, and IV B. only I and III C. only I, II, and IV D. only II and IV

C

Which of the following statements correctly describes a ribozyme? A. It is an enzyme that catalyzes the association between the large and small ribosomal subunits. B. It is a catalyst that uses RNA as a substrate. C. It is an RNA with catalytic activity. D. It is an enzyme that synthesizes RNA as part of the transcription process.

C

Which of the following statements correctly describes the difference between the leading strand and the lagging strand in DNA replication? A. There are different DNA polymerases involved in elongation of the leading strand and the lagging strand. B. The leading strand requires an RNA primer, whereas the lagging strand does not. C. The leading strand is synthesized continuously in the 5' → 3' direction, while the lagging strand is synthesized discontinuously in the 5' → 3' direction. D. The leading strand is synthesized in the 3' → 5' direction in a discontinuous fashion, while the lagging strand is synthesized in the 5' → 3' direction in a continuous fashion.

C

Which of the following statements is correct regarding the human X chromosomes? A. It is the same size as other chromosomes and has the same number of genes. B. It carries genes that determine an individual's biological sex. C. It is present in every somatic cell of males and females. D. It is referred to as an autosome.

C

Which of the following types of molecules help to hold the DNA strands apart while they are being replicated? A. DNA polymerase B. primase C. single-strand DNA binding proteins D. ligase

C

Within a differentiated B cell, the rearrangement of DNA sequences between variable regions and joining regions is accomplished by a(n)_____. A. reverse transcriptase B. epitopase C. recombinase D. RNA polymerase

C

Yearly vaccination of humans for influenza viruses is necessary because _____. A. of an increase in immunodeficiency diseases B. the flu can generate anaphylactic shock C. rapid mutation in flu viruses alters the surface proteins in infected host cells D. surviving the flu one year exhausts the immune system to nonresponsiveness the second year

C

You are asked to indicate the type and number of atoms in a molecule. Which representation would work best? A. ball-and-stick model B. structural formula C. molecular formula D. space-filling model

C

https://session.masteringbiology.com/problemAsset/2524883/1/urry11e_tb_04-10.jpg Which molecule shown can increase the concentration of hydrogen ions in a solution and is therefore an organic acid? A B C D

C

https://session.masteringbiology.com/problemAsset/2525078/1/urry11e_tb_08-14.jpg The figure illustrates the energy states associated with the reaction A + B ↔ C + D. Which of the following represents the activation energy required for the non-enzyme-catalyzed reaction in the figure? a b c d

C

https://session.masteringbiology.com/problemAsset/2525608/1/urry11e_tb_19-03.jpg Cells were infected with approximately 1,000 copies of either virus A or virus B at the 0 time point. At five-minute intervals, a sample of the virus and cell mixture was removed. The intact cells were removed from the sample, and the number of viruses per milliliter of culture was determined. Using the data in the figure, how long does it take for virus B to go through one lytic cycle? A. 15 minutes B. 45 minutes C. 60 minutes D. 30 minutes

C

"Marine cone snails from the genus Conus are estimated to consist of up to 700 species. These predatory molluscs have devised an efficient venom apparatus that allows them to successfully capture polychaete worms, other molluscs, or in some cases fish as their primary food sources. . . . conotoxins from Australian species of Conus . . . have the capacity to inhibit specifically the nicotinic acetylcholine receptors in higher animals." (B. G. Livett, K. R. Gayler, and Z. Khalil. 2004. Drugs from the sea: Conopeptides as potential therapeutics. Current Medicinal Chemistry 11:1715-23.) This particular conotoxin inhibits acetylcholine receptors that are located ________. A. on motor neuron dendrites B. on the presynaptic membrane of the neuromuscular junction C. along the motor neuron axon D. on the postsynaptic membrane, on the muscle cell

D

A glycosidic linkage is analogous to which of the following in proteins? A. a disulfide bond B. an amino group C. a β-pleated sheet D. a peptide bond

D

A heat-killed, phosphorescent (light-emitting) strain of bacteria is mixed with a living, non-phosphorescent strain. Further observations of the mixture show that some of the living cells are now phosphorescent. Which of the following observations would provide the best evidence that the ability to phosphoresce is a heritable trait? A. especially bright phosphorescence in the living strain B. evidence that protein passed from the heat-killed strain to the living strain C. evidence that DNA was passed from the heat-killed strain to the living strain D. phosphorescence in descendants of the living cells

D

A large population of laboratory animals has been allowed to breed randomly for a number of generations. After several generations, 25% of the animals display a recessive trait (aa), the same percentage as at the beginning of the breeding program. The rest of the animals show the dominant phenotype, with heterozygotes indistinguishable from the homozygous dominants. What is the estimated frequency of allele A in the gene pool? A. 0.75 B. 0.125 C. 0.25 D. 0.50

D

A part of an mRNA molecule with the following sequence is being read by a ribosome: 5-CCG-ACG-3 (mRNA). The following charged transfer RNA molecules (with their anticodons shown in the 3 to 5 direction) are available. Two of them can correctly match the mRNA so that a dipeptide can form. tRNA Anticodon Amino Acid GGC CGU UGC CCG ACG CGG Proline Alanine Threonine Glycine Cysteine Alanine Which of the following dipeptides will form from this mRNA? A. glycine-cysteine B. alanine-alanine C. cysteine-alanine D. proline-threonine

D

A particular triplet of bases in the template strand of DNA is 5-AGT-3. What would be the corresponding codon for the mRNA that is transcribed? A. 5-TCA-3 B. 3-ACU-5 C. 3-UGA-5 D. 3-UCA-5

D

A spaceship is designed to support animal life for a multiyear voyage to the outer planets of the solar system. Plants will be grown to provide oxygen and to recycle carbon dioxide. Since the spaceship will be too far from the sun for photosynthesis, an artificial light source will be needed. Suppose a plant has a unique photosynthetic pigment and the leaves of this plant appear to be reddish yellow. What wavelengths of visible light are absorbed by this pigment? A. red and yellow B. green and red C. green and yellow D. blue and violet

D

Action potentials are normally carried in only one direction: from the axon hillock toward the axon terminals. If you experimentally depolarize the middle of the axon to threshold, using an electronic probe, then _____. A. an action potential will be initiated and proceed only back toward the axon hillock B. no action potential will be initiated C. an action potential will be initiated and proceed only in the normal direction toward the axon terminal D. two action potentials will be initiated, one going toward the axon terminal and one going back toward the hillock

D

An ion with six protons, seven neutrons, and a charge of 2+ has an atomic number of ________. A. four B. seven C. five D. six

D

At a specific area of a chromosome, the sequence of nucleotides below is present where the chain opens to form a replication fork: 3' C C T A G G C T G C A A T C C 5' An RNA primer is formed starting at the underlined T (T) of the template. Which of the following represents the primer sequence? A. 5' G C C U A G G 3' B. 5' A C G T T A G G 3' C. 5' G C C T A G G 3' D. 5' A C G U U A G G 3'

D

Both the volume and the surface area for three different cells were measured. These values are listed in the following table: VolumeSurface Area Cell 1 9.3 μm3 26.5 μm2 Cell 2 12.2 μm3 37.1 μm2 Cell 3 17.6 μm3 40.6 μm2 Using data from the table above, select the best explanation for why that cell will be able to eliminate waste most efficiently? A. Cell 3, since it has the largest surface area, which will enable it to eliminate all of its wastes efficiently. B. Cell 3, because it is big enough to allow wastes to easily diffuse through the plasma membrane. C. Cell 1, since it has the smallest volume and will not produce as much waste as the other cells. D. Cell 2, since it has the highest ratio of surface area to volume, which facilitates the exchange of materials between a cell and its environment.

D

Carbon dioxide is split to form oxygen gas and carbon compounds in which of the following metabolic pathways? A. only photosynthesis B. only respiration C. photosynthesis and respiration D. neither photosynthesis nor respiration

D

Chemical equilibrium is relatively rare in living cells because metabolic pathways are interconnected. Which of the following statements describes an example of a reaction that may be at chemical equilibrium in a cell? A. an exergonic reaction in which the free energy at equilibrium is higher than the energy content of the reaction at any point away from equilibrium B. an endergonic reaction in an active metabolic pathway where the energy for that reaction is supplied only by heat from the environment C. an exergonic reaction in which the entropy change in the cell is precisely balanced by an opposite entropy change in the cell's surroundings D. a chemical reaction in which neither the reactants nor the products are being produced or consumed in any metabolic pathway at that time in the cell

D

Duchenne muscular dystrophy is a serious condition caused by a recessive allele of a gene on the human X chromosome. The patients have muscles that weaken over time because they have absent or decreased dystrophin, a muscle protein. They rarely live past their 20s. How likely is it for a woman to have this condition? A. Women can never have this condition. B. Only if a woman is XXX could she have this condition. C. One-fourth of the daughters of an affected man would have this condition. D. One-half of the daughters of an affected father and a carrier mother could have this condition.

D

During which of the following metabolic processes is most of the CO2 from the catabolism of glucose is released? A. electron transport B. oxidation of pyruvate to acetyl-CoA C. glycolysis D. the citric acid cycle

D

Elements found on the left side of the periodic table contain outer shells that are _____; these elements tend to form _____ in solution. A. almost empty; anions B. almost full; cations C. almost full; anions D. almost empty; cations

D

For the following question, match the key event of meiosis with the stages listed below. I. Prophase I V. Prophase II II. Metaphase I VI. Metaphase II III. Anaphase I VII. Anaphase II IV. Telophase I VIII. Telophase II Centromeres of sister chromatids disjoin and chromatids separate. A. III B. IV C. V D. VII

D

How does a scientific theory differ from a scientific hypothesis? A. Theories are proposed to test scientific hypotheses. B. Hypotheses are usually an explanation for a more general phenomenon; theories typically address more specific issues. C. Confirmed theories become scientific laws; hypotheses become theories. D. Theories are usually an explanation for a more general phenomenon; hypotheses typically address more specific issues.

D

How many unique gametes could be produced through independent assortment by an individual with the genotype AaBbCCDdEE? A. 64 B. 16 C. 4 D. 8

D

How might a single base substitution in the sequence of a gene affect the amino acid sequence of a protein encoded by the gene? A. It is not possible for a single base substitution to affect protein structure, because each codon is three bases long. B. The amino acid sequence would be substantially altered, because the reading frame would change with a single base substitution. C. All amino acids following the substitution would be affected, because the reading frame would be shifted. D. Only a single amino acid could change, because the reading frame would be unaffected.

D

If a biochemist discovers a new molecule, which of the following pieces of data would allow her to draw the conclusion that the molecule is a steroid hormone? I) The molecule is lipid soluble. II) The molecule is derived from a series of steps beginning with cholesterol. III) The molecule acts at a target tissue some distance from where it is produced. IV) The molecule uses a transport protein when in an aqueous solution such as blood. A. only II and IV B. only I and III C. only I, III, and IV D. I, II, III, and IV

D

If plant cells are grown on media containing radioactively labeled thymine for one generation, radioactively labeled macromolecules will be detected in which of the following? A. only in the nucleus B. only in the nucleus and chloroplasts C. only in the nucleus and mitochondria D. in the nucleus, mitochondria, and chloroplasts

D

In Drosophila melanogaster, vestigial wings are determined by a recessive allele of a gene that is linked to a gene with a recessive allele that determines black body color. T. H. Morgan crossed black-bodied, normal-winged females and gray-bodied, vestigial-winged males. The F1 were all gray bodied, normal winged. The F1 females were crossed to homozygous recessive males to produce testcross progeny. Morgan calculated the map distance to be 17 map units. Which of the following information is correct about the testcross progeny? A. black-bodied, vestigial-winged flies = 17% of the total B. black-bodied, normal-winged flies = 17% of the total C. black-bodied, normal-winged flies plus gray-bodied, vestigial-winged flies = 17% of the total D. gray-bodied, normal-winged flies plus black-bodied, vestigial-winged flies = 17% of the total

D

In a chemical reaction, the element 13Al will most preferably ________. A. lose five electrons and become positively charged B. gain five electrons and become negatively charged C. gain three electrons and become positively charged D. lose three electrons and become positively charged

D

In eukaryotes, there are several different types of RNA polymerase. Which type is involved in transcription of mRNA for a globin protein? A. RNA polymerase I B. primase C. RNA polymerase III D. RNA polymerase II

D

In the following structure where A and B represent two different elements, the valency of A is ________ and B is ________. https://session.masteringbiology.com/problemAsset/2524812/1/urry11e_tb_02-11.jpg A. eight; eight B. one; five C. three; five D. one; three

D

In the formula for determining a population's genotype frequencies, the "2" in the term 2pq is necessary because _____. A. the population is doubling in number B. the population is diploid C. heterozygotes have two alleles D. heterozygotes can come about in two ways

D

In the fractionation of homogenized cells using differential centrifugation, which of the following will require the greatest speed to form pellets at the bottom of the tube? A. nuclei B. mitochondria C. chloroplasts D. ribosomes

D

In which reactions of cellular respiration and fermentation does substrate-level phosphorylation occur? A. only in the citric acid cycle B. only in the electron transport chain C. only in glycolysis D. in both glycolysis and the citric acid cycle

D

Jams, jellies, preserves, honey, and other foods with high sugar content hardly ever become contaminated by bacteria, even when the food containers are left open at room temperature. This is because bacteria that encounter such an environment ____. A. are unable to metabolize the glucose or fructose, and thus starve to death B. are unable to swim through these thick and viscous materials C. are obligate anaerobes D. undergo death as a result of water loss from the cell

D

Measurements of the amount of DNA per nucleus were taken on a large number of cells from a growing fungus. The measured DNA levels ranged from 3 to 6 picograms per nucleus. In which stage of the cell cycle did the nucleus contain 6 picograms of DNA? A. S B. G1 C. G0 D. G2

D

Mendel's law of independent assortment has its basis in which of the following events of meiosis I? A. the division of cells at telophase B. crossing over of homologous pairs of chromosomes C. synapsis of homologous chromosomes D. alignment of pairs of homologous chromosomes along the middle of the cell

D

One of two major forms of a human condition called neurofibromatosis (NF 1) is inherited as a dominant gene, although it may range from mildly to very severely expressed. Which of the following is the best explanation for why a young, affected child is the first in her family to be diagnosed? A. The condition skipped a generation in the family. B. The mother carries the gene but does not express it. C. The child has one more chromosome than either of the parents. D. One of the parents has a mild expression of the gene.

D

Osteoporosis is a condition in which the density of bones is decreased so much that the individual is at a higher risk of fractures. The more calcium in the bones, the better the bone density. Which of the following would produce the greatest increase in bone calcium levels? A. glucagon receptor blocker B. calcitonin receptor blocker C. parathyroid hormone injection D. calcitonin injection

D

Plants convert ________. A. sunlight to mechanical energy. B. chemical energy to mechanical energy. C. mechanical energy to chemical energy. D. sunlight to chemical energy.

D

Rank the following one-base point mutations with respect to their likelihood of affecting the structure of the corresponding polypeptide (from most likely to least likely). 1. insertion mutation deep within an intron 2. substitution mutation at the third position of a codon in an exon 3. substitution mutation at the second position of a codon in an exon 4. deletion mutation within the first exon of the gene A. 1, 2, 3, 4 B. 2, 1, 4, 3 C. 3, 1, 4, 2 D. 4, 3, 2, 1

D

Sex determination in mammals is due to the SRY gene found on the Y chromosome. Which of the following situations could allow a person with an XX karyotype to develop a male phenotype? A. the presence of one normal and one shortened (deleted) X B. the presence of an extra autosomal chromosome C. the loss of the SRY gene from an autosome D. translocation of SRY to an X chromosome

D

Suppose 64% of a remote mountain village can taste phenylthiocarbamide (PTC) and must, therefore, have at least one copy of the dominant PTC taster allele. If this population conforms to Hardy-Weinberg equilibrium for this gene, what percentage of the population must be heterozygous for this trait? A. 32% B. 16% C. 40% D. 48%

D

Tadpoles must undergo a major metamorphosis to become frogs. This change includes reabsorption of the tail, growth of limbs, calcification of the skeleton, increase in rhodopsin in the eye, development of lungs, change in hemoglobin structure, and reformation of the gut from the long gut of an herbivore to the short gut of a carnivore. Amazingly, all of these changes are induced by thyroxine. What is the most likely explanation for such a wide array of effects of thyroxine? A. Some tissues have membrane receptors for thyroxine, while other tissues have thyroxine receptors within the nucleus. B. There are many different forms of thyroxine, each specific to a different tissue. C. Different releasing hormones release thyroxine to different tissues. D. Different tissues have thyroxine receptors that activate different signal transduction pathways.

D

The complement system is ________. A. a group of proteins that includes interferons and interleukins B. a set of proteins involved in innate but not acquired immunity C. a set of proteins that act individually to attack and lyse microbes D. a group of proteins that act together in a cascade fashion

D

The first class of antiviral drugs developed to treat HIV infection, such as AZT, were known as reverse transcriptase inhibitors. How did these drugs carry out their functions? A. The drugs targeted and destroyed the viral genome before it could be reverse transcribed into DNA. B. The drugs prevented host cells from producing the enzymes used by the virus to replicate its genome. C. The drug molecules bonded to the dsDNA genome of the virus in such a way that it could not separate for replication to occur. D. The drug molecules bonded to the viral reverse transcriptase enzyme, thus preventing the virus from making a DNA copy of its RNA genome.

D

The sodium-potassium pump is called an electrogenic pump because it ________. A. pumps equal quantities of Na+ and K+ across the membrane in opposite directions B. decreases the voltage difference across the membrane C. generates voltage across the membrane D. is used to drive the transport of glucose against a concentration gradient

D

The solutions in the two arms of this U-tube are separated by a membrane that is permeable to water and glucose but not to sucrose. Side A is half-filled with a solution of 2 M sucrose and 1 M glucose. Side B is half-filled with 1 M sucrose and 2 M glucose. Initially, the liquid levels on both sides are equal. A U-shaped tube is shown with the water-permeable membrane at the center of the bottom of the U. The left side, labeled A, is filled with a mixture of 2 M sucrose and 1 M glucose. The right side, labeled B, is filled with a mixture of 1 M sucrose and 2 M. glucose. The two sides of the tube are level with each other. In the U-tube illustrated above, ________. A. side A is more turgid than side B B. side A is hypotonic to side B C. side A is hypertonic to side B D. side A is isotonic to side B

D

The solutions in the two arms of this U-tube are separated by a membrane that is permeable to water and glucose but not to sucrose. Side A is half-filled with a solution of 2 M sucrose and 1 M glucose. Side B is half-filled with 1 M sucrose and 2 M glucose. Initially, the liquid levels on both sides are equal. A U-shaped tube is shown with the water-permeable membrane at the center of the bottom of the U. The left side, labeled A, is filled with a mixture of 2 M sucrose and 1 M glucose. The right side, labeled B, is filled with a mixture of 1 M sucrose and 2 M. glucose. The two sides of the tube are level with each other. Which of the following will be true when the system illustrated above reaches equilibrium? A. The water levels will be unchanged. B. The water level will be higher in side B than in side A. C. The concentration of sucrose on side A will be greater than the concentration of sucrose on side B. D. The water level will be higher in side A than in side B.

D

What happens to the free energy released as electrons are passed from photosystem II to photosystem I through a series of electron carriers? A. It excites electrons of the reaction center in photosystem I. B. It is used to synthesize ATP through substrate-level phosphorylation. C. It is used to phosphorylate NAD+ to NADPH. D. It is used to establish and maintain a proton gradient.

D

What was the most significant conclusion that Gregor Mendel drew from his experiments with pea plants? A. There is considerable genetic variation in garden peas. B. Recessive genes occur more frequently in the F1 generation than do dominant ones. C. Genes are composed of DNA. D. Traits are inherited in discrete units and are not the result of "blending."

D

When a plant cell, such as one from a tulip leaf, is submerged in a hypertonic solution, what is likely to occur? A. The cell will become flaccid. B. The cell will burst. C. The cell will become turgid. D. Plasmolysis will shrink the interior of the cell.

D

When an ionic compound such as sodium chloride (NaCl) is placed in water, the component atoms of the NaCl crystal dissociate into individual sodium ions (Na+) and chloride ions (Cl-). In contrast, the atoms of covalently bonded molecules (e.g., glucose, sucrose, glycerol) do not generally dissociate when placed in aqueous solution. Which of the following solutions would be expected to contain the greatest number of solute particles (molecules or ions)? A. 1 liter of 1.0 M glucose B. 1 liter of 0.5 M NaCl C. 1 liter of 1.0 M NaCl and 1 liter of 1.0 M glucose will contain equal numbers of solute particles. D. 1 liter of 1.0 M NaCl

D

Which of the following are least likely to diffuse through the phospholipid bilayer of a cell membrane? A. carbon dioxide B. small hydrophobic molecules C. large hydrophobic molecules D. small ions

D

Which of the following characteristics is most likely to be associated with an enzyme that catalyzes two different chemical reactions? A. The enzyme is subject to competitive inhibition and allosteric regulation. B. The enzyme is composed of at least two subunits. C. The enzyme contains α-helices and β-pleated sheets. D. Either the enzyme has two distinct active sites or the substrates involved in the two reactions have very similar structures.

D

Which of the following characteristics is typical of the lytic cycle of a bacteriophage? A. The viral genome replicates without destroying the host. B. Viral DNA is incorporated into the host genome. C. The virus-host relationship usually lasts for generations. D. A large number of phages are released at a time.

D

Which of the following characteristics would you expect of a eukaryotic organism that lacks the enzyme telomerase? A. an inability to produce Okazaki fragments B. an inability to repair thymine dimers C. a high probability of somatic cells becoming cancerous D. a reduction in chromosome length in gametes

D

Which of the following effects might be caused by reduced or very little active telomerase activity? A. Cells maintain normal functioning. B. Telomere lengthens in germ cells. C. Cells may become cancerous. D. Cells age and begin to lose function.

D

Which of the following is the correct sequence that describes the excitation and contraction of a skeletal muscle fiber? 1. Tropomyosin shifts and unblocks the cross-bridge binding sites. 2. Calcium is released and binds to the troponin complex. 3. Transverse tubules depolarize the sarcoplasmic reticulum. 4. The thin filaments are ratcheted across the thick filaments by the heads of the myosin molecules using energy from ATP. 5. An action potential in a motor neuron causes the axon to release acetylcholine, which depolarizes the muscle cell membrane. A. 2 → 1 → 3 → 5 → 4 B. 1 → 2 → 3 → 4 → 5 C. 2 → 3 → 4 → 1 → 5 D. 5 → 3 → 2 → 1 → 4

D

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

D

Which of the following metabolic processes take place in the cytosol of a eukaryotic cell? A. fermentation and chemiosmosis B. citric acid cycle C. oxidation of pyruvate to acetyl CoA D. glycolysis and fermentation

D

Which of the following molecules is most similar in structure to ATP? A. a DNA nucleotide B. a pentose sugar C. an amino acid with three phosphate groups attached D. an RNA nucleotide

D

Which of the following phrases correctly defines what one map unit is? A. the physical distance between two linked genes B. 1 nanometer of distance between two genes C. the recombination frequency between two genes assorting independently D. a 1% frequency of recombination between two genes

D

Which of the following processes generates a proton-motive force in mitochondria? A. lowering of pH in the mitochondrial matrix B. the flow of protons through ATP synthase down their concentration gradient C. the reduction of NAD+ by the first electron carrier in the electron transport chain D. pumping of hydrogen ions from the mitochondrial matrix across the inner membrane and into the intermembrane space

D

Which of the following processes is driven by chemiosmosis? A. ATP hydrolysis B. substrate-level phosphorylation C. reduction of NAD+ to NADH D. oxidative phosphorylation

D

Which of the following provides the best evidence that cell-signaling pathways evolved early in the history of life? A. Bacteria and yeast cells signal each other in a process called quorum sensing. B. Most signals in all types of cells are received by cell surface receptors. C. Cell-signaling pathways are seen in "primitive" cells such as bacteria and yeast. D. Signal transduction molecules identified in distantly related organisms are similar.

D

Which of the following scenarios describes an example of epistasis? A. In Drosophila (fruit flies), white eyes can be due to an X-linked gene or to a combination of other genes. B. In cacti, there are several genes for the type of spines. C. Recessive genotypes for each of two genes (aabb) results in an albino corn snake. D. In rabbits and many other mammals, one genotype (ee) prevents any fur color from developing.

D

Which of the following statements accurately describes the lysogenic cycle of lambda (λ) phage? A. After infection, the viral genes immediately turn the host cell into a lambda-producing factory, and the host cell then lyses. B. Most of the prophage genes are activated by the product of a particular prophage gene. C. The phage DNA is copied and exits the cell as a phage. D. The phage genome is integrated in the host chromosome where it is replicated along with the host genome.

D

Which of the following statements accurately describes the structure of a eukaryotic chromosome? A. It is composed of a single strand of DNA. B. It is constructed as a series of nucleosomes wrapped around two DNA molecules. C. It has different numbers of genes in different cell types of an organism. D. It is a single linear molecule of double-stranded DNA plus proteins.

D

Which of the following viruses would most likely have reverse transcriptase inside them? A. an RNA-based lytic virus B. a DNA-based lytic virus C. a DNA-based lysogenic virus D. an RNA-based lysogenic virus

D

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

D

Why do hydrolysis reactions occur more readily in solution than dehydration reactions? A. Hydrolysis reactions are exergonic and decrease entropy of the system. B. Hydrolysis reactions are endergonic and increase entropy of the system. C. Hydrolysis reactions increase G, or Gibbs free energy of the system. D. Hydrolysis reactions are exergonic and increase entropy of the system.

D

You briefly expose bacteria undergoing DNA replication to radioactively labeled nucleotides. When you centrifuge the DNA isolated from the bacteria, the DNA separates into two classes. One class of labeled DNA includes very large molecules (thousands or even millions of nucleotides long), and the other includes short stretches of DNA (several hundred to a few thousand nucleotides in length). Which two classes of DNA do these different samples represent? A. leading strands and RNA primers B. Okazaki fragments and RNA primers C. lagging strands and Okazaki fragments D. leading strands and Okazaki fragments

D

https://session.masteringbiology.com/problemAsset/2524839/1/urry11e_tb_03-01.jpg Based on your knowledge of the polarity of water molecules, the solute molecule depicted is most likely ________. A. without charge B. negatively charged C. nonpolar D. positively charged

D

https://session.masteringbiology.com/problemAsset/2524886/1/urry11e_tb_04-11.jpg Which molecule shown above contains a functional group that is a part of the molecule known as the "energy currency of living organisms"? A B C D f

D

https://session.masteringbiology.com/problemAsset/2525076/1/urry11e_tb_08-12.jpg The figure illustrates the energy states associated with the reaction A + B ↔ C + D. Which of the following in the figure would be the same in either an enzyme-catalyzed or a noncatalyzed reaction? a b c d

D

https://session.masteringbiology.com/problemAsset/2525103/1/urry11e_tb_09-03.jpg If pyruvate oxidation is blocked, what will happen to the levels of oxaloacetate and citric acid in the citric acid cycle shown in the accompanying figure? A. Both oxaloacetate and citric acid will accumulate. B. Both oxaloacetate and citric acid will decrease. C. Oxaloacetate will decrease and citric acid will accumulate. D. Oxaloacetate will accumulate and citric acid will decrease.

D

https://session.masteringbiology.com/problemAsset/2525262/1/urry11e_tb_12-04.jpg In the figure, G1 is represented by which numbered part(s) of the cycle? A. III B. II C. IV D. I and V

D

https://session.masteringbiology.com/problemAsset/2525426/1/urry11e_tb_15-04.jpg In a series of mapping experiments, the recombination frequencies for four different linked genes of Drosophila were determined as shown in the figure. Based on this information, what is the order of these genes on a chromosome map? A. rb-cn-vg-b B. vg-cn-b-rb C. cn-rb-b-vg D. b-rb-cn-vg

D

https://session.masteringbiology.com/problemAsset/2525443/1/urry11e_tb_15-10.jpg The pedigree in the figure shows the transmission of a trait in a particular family. Based on this pattern of transmission, the trait is most likely ________. A. sex-linked dominant B. sex-linked recessive C. autosomal dominant D. mitochondrial

D

https://session.masteringbiology.com/problemAsset/2525470/2/urry11e_tb_16-01.jpg In the late 1950s, Meselson and Stahl grew bacteria in a medium containing "heavy" nitrogen (15N) and then transferred them to a medium containing 14N (a lighter isotope). Which of the results in the figure would be expected after one round of DNA replication in the presence of 14N? A B C D

D

https://session.masteringbiology.com/problemAsset/2525500/1/urry11e_tb_17-05.jpg What amino acid sequence will be generated, based on the following mRNA codon sequence? 5-AUG-UCU-UCG-UUA-UCC-UUG-3 A. Met-Ser-Leu-Ser-Leu-Ser B. Met-Glu-Arg-Arg-Glu-Leu C. Met-Arg-Glu-Arg-Glu-Arg D. Met-Ser-Ser-Leu-Ser-Leu

D

https://session.masteringbiology.com/problemAsset/2525501/1/urry11e_tb_17-06.jpg Refer to the figure. Which of the triplets below is a possible anticodon for a tRNA that transports proline to a ribosome? A. 3-UUC-5 B. 3-CCC-5 C. 3-CCG-5 D. 3-GGC-5

D