BIL150- past study guides
NADH and pyruvate
In addition to ATP, what are the end products of glycolysis? A) CO₂ and H₂O B) CO₂ and pyruvate C) NADH and pyruvate D) CO₂ and NADH
C4 plant
In an experiment studying photosynthesis performed during the day, you provide a plant with radioactive carbon (14C) dioxide as a metabolic tracer. The 14C is incorporated first into oxaloacetate. The plant is best characterized as a A) heterotroph. B) C4 plant. C) C3 plant. D) CAM plant. E) chemoautotroph.
a regulatory protein is removed from DNA
In negative control of transcription, a gene is activated when A) a kinase adds a phosphate to DNA. B) lactose is transported into the cell. C) a regulatory protein binds to DNA. D) a regulatory protein is removed from DNA.
25%
In rabbits, the homozygous CC is normal, Cc results in deformed legs, and cc results in very short legs. The genotype BB produces black fur, Bb brown fur, and bb white fur. If a cross is made between brown rabbits with deformed legs and white rabbits with deformed legs, what percentage of the offspring would be expected to have deformed legs and white fur? A) 25% B) 33% C) 0% D) 100% E) 50%
25%
In tigers, a recessive allele causes a white tiger (absence of fur pigmentation). If two phenotypically normal tigers that are heterozygous at this locus are mated, what percentage of their offspring is expected to be white? A) 50% B) 75% C) about 66% D) about 90% E) 25%
acidification would decrease dissolved carbonate concentrations and hinder growth of corals and shell-building animals
Increased atmospheric CO2 concentrations will make seawater more acidic. How would acidification of seawater affect marine organisms? a) Acidification would decrease dissolved carbonate concentrations and hinder growth of corals and shell-building animals. b) Acidification would increase dissolved carbonate concentrations and promote faster growth of corals and shell-building animals. c) Acidification would increase dissolved bicarbonate concentrations, and cause increased calcification of corals and shellfish. d) Acidification would decrease dissolved carbonate concentrations and promote faster growth of corals and shell-building animals. e) Acidification would increase dissolved carbonate concentrations and hinder growth of corals and shell-building animals.
most enzyme molecules are occupied by substrate at high reactant concentrations
why does the reaction rate plateau at higher reactant concentrations? A) The activation energy for the reaction increases with reactant concentration. B) Most enzyme molecules are occupied by substrate at high reactant concentrations. C) The rate of the reverse reaction increases with reactant concentration. D) Feedback inhibition by product occurs at high reactant concentrations. E) The reaction nears equilibrium at high reactant concentrations.
40
) If a DNA sample were composed of 10% thymine, what would be the percentage of guanine? a) 20 b) 40 c) 80 d) 10 e) impossible to tell from the information given
either hydroxyl or carboxyl groups
16) Molecules with which functional groups may form polymers via dehydration reactions? a) hydroxyl groups b) either hydroxyl or carboxyl groups c) carboxyl groups d) either carbonyl or carboxyl groups carbonyl groups
albino is recessive; black is dominant
A black guinea pig crossed with an albino guinea pig produced 12 black offspring. When the albino was crossed with a second black animal, 6 blacks and 6 albinos were obtained. What is the best explanation for this genetic situation? A) Albino is recessive; black is dominant. B) Albino is dominant; black is incompletely dominant. C) Albino and black are codominant. D) Albino is recessive; black is recessive. E) None of the above applies.
16;16
A group of cells is assayed for DNA content immediately following mitosis and is found to have an average of 8 picograms of DNA per nucleus. How many picograms would be found at the end of S and the end of G2? A) 8; 8 B) 8; 16 C) 16; 8 D) 16; 16
ATPase activity must be pumping calcium from the cytosol to the SR against the concentration gradient
A number of systems for pumping ions across membranes are powered by ATP. Such ATP-powered pumps are often called ATPases although they don't 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 transferring i to the SR to enable this to occur. B) ATPase activity must be pumping calcium from the cytosol to the SR against the concentration gradient. C) ATPase activity must be opening a channel for the calcium ions to diffuse back into the SR along the concentration gradient. D) ATPase activity must be routing calcium ions from the SR to the cytosol, and then to the cell's environment. E) ATPase activity must be powering an inflow of calcium from the outside of the cell into the SR.
63 chromosomes, in 21 sets of 3
A triploid cell contains sets of three homologous chromosomes. If a cell of a usually diploid species with 42 chromosomes per cell is triploid, this cell would be expected to have which of the following? A) 63 chromosomes in pairs B) 63 chromosomes in 21 sets of 3 C) 63 chromosomes, each with three chromatids D) 21 chromosome pairs and 21 unique chromosomes
DNA
Among these biological polymers, which has the least structural variety? a) DNA b) proteins c) RNA polysaccharides
carbon, oxygen, nitrogen, hydrogen
About twenty-five of the ninety-two natural elements are known to be essential to life. Which four of these twenty-five elements make up approximately 96 percent of living matter? A) carbon, sodium, hydrogen, nitrogen B) carbon, oxygen, phosphorus, hydrogen C) oxygen, hydrogen, calcium, nitrogen D) carbon, hydrogen, nitrogen, oxygen
II, III, I
Above are the different stages of cell signaling: I. Response II. Reception III. Transduction What is the correct order in which cell signaling occurs? A) I,II,III B) II,I,III C) II,III,I D) I,III,II
cyclic electron flow
As a research scientist, you measure the amount of ATP and NADPH consumed by the Calvin cycle in 1 hour. You find 30,000 molecules of ATP consumed, but only 20,000 molecules of NADPH. Where did the extra ATP molecules come from? A) linear electron flow B) photosystem I C) photosystem II D) cyclic electron flow E) chlorophyll
synthesis of ATP
Assume a thylakoid is somehow punctured so that the interior of the thylakoid is no longer separated from the stroma. This damage will most directly affect the _____. A) splitting of water B) flow of electrons from photosystem II to photosystem I C) synthesis of ATP D) reduction of NADP+
3' ; 5'-to-3' ; continuously; discontinuously
DNA polymerase adds nucleotides to the ____ end of the DNA strand, therefore, DNA is synthesized in the _____ direction on both the leading and lagging strand, with the leading strand being synthesized _____ and the lagging strand being synthesized ______. A. 3' ; 5'-to-3' ; continuously; discontinuously B. 5' ; 5'-to-3' ; continuously; discontinuously C. 3' ; 5'-to-3' ; continuously; continuously D. 5' ; 5'-to-3' ; discontinuously; continuously
α-amanitin efficiently interferes with the action of RNA polymerase II, but not RNA polymerase I or III.
Death cap mushrooms produce a substance called -amanitin. α-amanitin efficiently blocks synthesis of mRNA, but not of tRNA or rRNA in eukaryotic organisms. How is that possible? A) α-amanitin efficiently interferes with the action of RNA polymerase I, but not RNA polymerase II or III. B) α-amanitin efficiently interferes with RNA polymerase III, but not RNA polymerase I and II. C) α-amanitin efficiently blocks the action of one or more basic transcription factors. D) α-amanitin efficiently interferes with the action of RNA polymerase II, but not RNA polymerase I or III.
-20kcal/mol
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) -40 kcal/mol B) +40 kcal/mol C) +20 kcal/mol D) -20 kcal/mol E) 0 kcal/mol
1/2; no
Glucose-6-phosphate dehydrogenase deficiency (G6PD) is inherited as a recessive allele of an X-linked gene in humans. A woman whose father suffered from G6PD marries a normal man. (a) What proportion of their sons is expected to be G6PD? (b) If the husband was not normal but was G6PD deficient, would you change your answer in part (a)? (a) 100%; (b) no (b) (a) zero; (b) no (c) 1/2; (b) yes (d) 1/2; (b) no
a gene library contains many different cloned DNA sequences; a gene clone contains one type of DNA sequence
How does a gene library differ from a gene clone? A) A gene library contains many different cloned DNA sequences; a gene clone contains one type of DNA sequence. B) A gene library contains one type of cloned DNA sequence; a gene clone contains many different DNA sequences. C) A gene library is a much longer DNA sequence than a gene clone. D) A gene library is a much shorter DNA sequence than a gene clone. E) A gene library is sequence information stored in a computerized database; a gene clone is an actual sequence of DNA.
humans have enzymes that can hydrolyze the α glycosidic linkages of starch but not the β glycosidic linkages of cellulose.
Humans can digest starch but not cellulose because a) the monomer of starch is glucose, while the monomer of cellulose is glucose with a nitrogen-containing group. b) humans have enzymes that can hydrolyze the α glycosidic linkages of starch but not the β glycosidic linkages of cellulose. c) humans have enzymes that can hydrolyze the β glycosidic linkages of starch but not the α glycosidic linkages of cellulose. d) humans harbor starch-digesting bacteria in the digestive tract. e) the monomer of starch is glucose, while the monomer of cellulose is galactose.
it has half the amount of DNA as the cell that began meiosis
If a cell has completed meiosis I and is just beginning meiosis II, which of the following is an appropriate description of its contents? A) It has half the amount of DNA as the cell that began meiosis. B) It has half the chromosomes but twice the DNA of the originating cell. C) It has one-fourth the DNA and one-half the chromosomes as the originating cell. D) It is identical in content to another cell formed from the same meiosis I event
concentration of OH- has decreased to one-tenth what it was at pH 9
If the pH of a solution is decreased from 9 to 8, it means that the______ a) concentration of H+ has increased tenfold (10X) compared to what it was at pH 9. b) concentration of H+ has increased tenfold (10X) and the concentration of OH- has decreased to one-tenth (1/10) what they were at pH 9. c) concentration of OH- has decreased to one-tenth (1/10) what it was at pH 9. d) concentration of OH- has increased tenfold (10X) compared to what it was at pH 9. e) concentration of H+ has decreased to one-tenth (1/10) what it was at pH 9.
when vitamin B12 binds to the repressor, the repressor binds to the operator
Imagine that you discover a bacterial operon involved in the synthesis of vitamin B12. This operon is regulated by a repressor protein that binds to an operator sequence. Vitamin B12 is the allosteric effector of the repressor—the molecule that binds to the repressor to affect its activity. Predict how vitamin B12 will influence repressor activity. A) When vitamin B12 binds to the repressor, the repressor binds to the operator. B) When vitamin B12 binds to the repressor, the repressor cannot bind to the operator. C) When vitamin B12 binds to the repressor, the repressor can bind to RNA polymerase. D) When vitamin B12 binds to the repressor, the repressor cannot bind to RNA polymerase.
competitive inhibition
Increasing the substrate concentration in an enzymatic reaction could overcome which of the following? A) insufficient cofactors B) allosteric inhibition C) saturation of the enzyme activity D) denaturization of the enzyme E) competitive inhibition .
the absorption of heat by the breaking of hydrogen bonds
Many mammals control their body temperature by sweating. Which property of water is most directly responsible for the ability of sweat to lower body temperature? a) water's ability to dissolve molecules in the air b) water's high surface tension c) the absorption of heat by the breaking of hydrogen bonds d) the release of heat by the formation of hydrogen bonds
G2
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) G1 B) S C) G2 D) M
telomerase
Of the enzymes listed associated with DNA replication, which would also be most associated with cancer cell proliferation? A. DNA polymerase I B. Telomerase C. Primase D. Nuclease
translocation
Once a peptide has been formed between the amino acid attached to the tRNA in the P site and the amino acid associated with the tRNA in the A site, which process on the list occurs next? A) translocation B) reading of the next codon of mRNA C) initiation D) the codon-anticodon hydrogen bonds holding the tRNA in the A site are broken
messenger RNA is transcribed from a single gene and transfers information from the DNA in the nucleus to the cytoplasm, where protein synthesis takes place
Once researchers identified DNA as the unit of inheritance, they asked how information was transferred from the DNA in the nucleus to the site of protein synthesis in the cytoplasm. What is the mechanism of information transfer? A) DNA from a single gene is replicated and transferred to the cytoplasm, where it serves as a template for protein synthesis. B) Messenger RNA is transcribed from a single gene and transfers information from the DNA in the nucleus to the cytoplasm, where protein synthesis takes place. C) Proteins transfer information from the nucleus to the ribosome, where protein synthesis takes place. D) Lipids are soluble in the nuclear membrane and serve to transfer information from the DNA to the cytoplasm, where protein synthesis takes place.
are synthesized from subunits by dehydration reactions
Polysaccharides, triacylglycerides, and proteins are similar in that they a) are synthesized as a result of peptide bond formation between monomers. b) all contain nitrogen in their monomer building blocks. c) are synthesized from subunits by dehydration reactions. d) are synthesized from monomers by the process of hydrolysis. e) are decomposed into their subunits by dehydration reactions.
the change in a protein's charge leading to a conformational change
Protein kinases are enzymes that catalyze phosphorylation of target proteins at specific sites, whereas protein phosphatases catalyze removal of phosphate(s) from phosphorylated proteins. Phosphorylation and dephosphorylation can function as an on-off switch for a protein's activity, most likely through A) a change in the optimal temperature at which a reaction will occur. B) the change in a protein's charge leading to a conformational change. C) the excision of one or more peptides. D) the change in a protein's charge leading to cleavage. E) a change in the optimal pH at which a reaction will occur.
are mirror images of one another
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 one another. b) differ in the location of their double bonds. c) have identical chemical formulas but differ in the branching of their carbon skeletons. d) differ in the arrangement of atoms around their double bonds. e) exist in either linear chain or ring forms.
to test for liberation of O2 in the light
Some photosynthetic organisms contain chloroplasts that lack photosystem II, yet are able to survive. The best way to detect the lack of photosystem II in these organisms would be A) to do experiments to generate an action spectrum. B) to determine if they have thylakoids in the chloroplasts. C) to test for liberation of O2 in the light. D) to test for CO2 fixation in the dark. E) to test for production of either sucrose or starch.
it is a competitive inhibitor
Succinate dehydrogenase catalyzes the conversion of succinate to fumarate in the Citric Acid Cycle. The reaction is inhibited by malonic acid, which resembles succinate but cannot be acted upon by succinate dehydrogenase. Increasing the ratio of succinate to malonic acid reduces the inhibitory effect of malonic acid. What is malonic acid's role with respect to succinate dehydrogenase? A) It blocks the binding of fumarate. B) It is able to bind to succinate. C) It is an allosteric regulator. D) It is a competitive inhibitor. E) It is a noncompetitive inhibitor.
1/64
Suppose two AaBbCc individuals are mated. Assuming that the genes are not linked, what fraction of the offspring are expected to be homozygous recessive for the three traits? A) 1/4 B) 1/8 C) 1/16 D) 1/64 E) 1/256
binding with a receptor protein that enters the nucleus and activates specific genes
Testosterone functions inside a cell by A) acting as a steroid signal receptor that activates ion channel proteins. B) acting as a signal receptor that activates tyrosine kinases. C) coordinating a phosphorylation cascade that increases spermatogenesis. D) becoming a second messenger that inhibits adenylyl cyclase. E) binding with a receptor protein that enters the nucleus and activates specific genes.
substrate level phosphorylation
The ATP made during glycolysis is generated by A) substrate-level phosphorylation. B) electron transport. C) photophosphorylation. D) oxidation of NADH to NAD⁺.
leucine would be in the interior and serine would be on the exterior of the globular protein
The R group or side chain of the amino acid serine is -CH2-OH. The R group or side chain of the amino acid leucine is -CH2-CH-(CH3)2. Where would you expect to find these amino acids in a globular protein in aqueous solution? a) Serine would be in the interior, and leucine would be on the exterior of the globular protein. b) Both serine and leucine would be in the interior and on the exterior of the globular protein. c) Both serine and leucine would be on the exterior of the globular protein. d) Leucine would be in the interior, and serine would be on the exterior of the globular protein. e) Both serine and leucine would be in the interior of the globular protein.
water
The electrons of photosystem II are excited and transferred to electron carriers. From which molecule or structure do the photosystem II replacement electrons come? A) the electron carrier, plastocyanin B) photosystem I C) water D) oxygen
glycogen
The enzyme amylase can break glycosidic linkages between glucose monomers only if the monomers are the α form. Which of the following could amylase break down? a) cellulose b) chitin c) glycogen and chitin only d) glycogen e) glycogen, cellulose, and chitin
arrangement of carbon, hydrogen, and oxygen atoms
The figure shows the structures of glucose and fructose. These two molecules differ in the a) number of oxygen atoms joined to carbon atoms by double covalent bonds. b) number of carbon, hydrogen, and oxygen atoms. c) number of carbon, hydrogen, and oxygen atoms; the types of carbon, hydrogen, and oxygen atoms; and the arrangement of carbon, hydrogen, and oxygen atoms. d) types of carbon, hydrogen, and oxygen atoms. e) arrangement of carbon, hydrogen, and oxygen atoms.
most of the free energy available from the oxidation of glucose remains in pyruvate, one of the products of glycolysis
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) Glycolysis consists of many enzymatic reactions, each of which extracts some energy from the glucose molecule. C) Glycolysis is a very inefficient reaction, with much of the energy of glucose released as heat. D) There is no CO2 or water produced as products of glycolysis. E) Most of the free energy available from the oxidation of glucose is used in the production of ATP in glycolysis.
will form hydrogen bonds with water molecules
The illustration shows a representation of formic acid. A formic acid molecule a) consists of largely nonpolar covalent bonds. b) is held together by hydrogen bonds. c) has a tetrahedral configuration of hybrid electron orbitals for the carbon atom. d) will form hydrogen bonds with water molecules. e) has a tetrahedral shape and will form hydrogen bonds with water molecules.
the hydrogenated vegetable oil stays solid at room temperature
The label on a container of margarine lists "hydrogenated vegetable oil" as the major ingredient. What is the result of adding hydrogens to vegetable oil? a) The hydrogenated vegetable oil stays solid at room temperature. b) The hydrogenated vegetable oil has a lower melting point. c) The hydrogenated vegetable oil has more "kinks" in the fatty acid chains. d) The hydrogenated vegetable oil is less likely to clog arteries. e) The hydrogenated vegetable oil has fewer trans fatty acids.
photosynthesis preferentially uses carbon dioxide molecules with carbon-12 and the lower carbon-13/carbon-12 ratio propagates through the food chain
The organic molecules in living organisms have a measurably lower ratio of carbon-13/carbon-12, two stable isotopes of carbon that comprise approximately 1.1% and 98.9% of atmospheric carbon, respectively. What is a reasonable explanation for this phenomenon? a) Carbon dioxide molecules with carbon-13 stay in the upper atmosphere and are less available to terrestrial plants and algae. b) Carbon-13 has a different valence electron configuration and is therefore less chemically reactive than carbon-12. c) Carbon dioxide molecules containing carbon-13 are heavier and sink into the ocean depths, making them less available to living organisms. d) Oxygen atoms preferentially react with carbon-13, thereby enriching the atmosphere with carbon dioxide molecules containing carbon-13 atoms. e) Photosynthesis preferentially uses carbon dioxide molecules with carbon-12, and the lower carbon-13/carbon-12 ratio propagates through the food chain.
the electrons shared between the oxygen and hydrogen atoms spend more time around the oxygen atom nucleus than around the hydrogen atom nucleus
The partial negative charge in a molecule of water occurs because a) the electrons shared between the oxygen and hydrogen atoms spend more time around the oxygen atom nucleus than around the hydrogen atom nucleus. b) the oxygen atom has two pairs of electrons in its valence shell that are not neutralized by hydrogen atoms. c) one of the hydrogen atoms donates an electron to the oxygen atom. d) the oxygen atom forms hybrid orbitals that distribute electrons unequally around the oxygen nucleus. e) the oxygen atom acquires an additional electron.
the existence of unpaired electrons in the valence shell
The reactivity of an atom arises from a) the existence of unpaired electrons in the valence shell. b) the energy difference between the s and p orbitals. c) the average distance of the outermost electron shell from the nucleus. d) the sum of the potential energies of all the electron shells. e) the potential energy of the valence shell.
the lac operator
The tyrosinase gene used by Cronin et al. contained the protein-coding sequence and the normal mouse regulatory sequences. These regulatory sequences provide positive control of tyrosinase transcription. If nothing else is done to this DNA and it is introduced into a mouse, tyrosinase will always be expressed. Because the goal was to regulate expression of tyrosinase, what portion of the lac operon do you think was added to this mouse gene? A) the lacZ gene B) the lacY gene C) the lacI gene D) the lac operator E) CAP
the CO2 acceptor concentration would increase when the CO2 is cut off, but decrease when the light is cut off
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 stay the same regardless of the CO2 or light. B) The CO2 acceptor concentration would increase when either the CO2 or light are 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. E) The CO2 acceptor concentration would increase when the CO2 is cut off, but decrease when the light is cut off.
no glucose; high lactose
Under what kind of conditions would you expect the expression of the lac gene in E. Coli. to be expressed at the highest rate? A. High glucose, high lactose B. Low glucose, low lactose C. No glucose, high lactose D. Low glucose, high lactose
an electron is excited
What event accompanies energy absorption by chlorophyll (or other pigment molecules of the antenna complex)? A) ATP is synthesized from the energy absorbed. B) A carboxylation reaction of the Calvin cycle occurs. C) Electrons are stripped from NADPH. D) An electron is excited
both the relative abundances of the elements and the emergent properties of the compound made from these elements
What factors are most important in determining which elements are most common in living matter? a) the relative abundances of the elements in Earth's crust and atmosphere b) the chemical stability of the elements c) the reactivity of the elements with water d) both the relative abundances of the elements and the emergent properties of the compounds made from these elements e) the emergent properties of the simple compounds made from these elements
the DNA sequence of the ends of the DNA to be amplified must be known
What information is critical to the success of PCR itself? A) The DNA sequence of the ends of the DNA to be amplified must be known. B) The complete DNA sequence of the DNA to be amplified must be known. C) The sequence of restriction enzyme recognition sites in the DNA to be amplified must be known. D) The sequence of restriction enzyme recognition sites in the DNA to be amplified and in the plasmid where the amplified DNA fragment will be cloned must be known.
they are located close together on the same chromosome
What is the reason that linked genes are inherited together? A) They are located close together on the same chromosome. B) The number of genes in a cell is greater than the number of chromosomes. C) Alleles are paired together during meiosis. D) Genes align that way during metaphase I of meiosis
hydrogen bonds between the amino group of one peptide bond and the carboxyl group of another peptide bond
What maintains the secondary structure of a protein? a) hydrophobic interactions b) hydrogen bonds between the R groups c) peptide bonds d) disulfide bonds e) hydrogen bonds between the amino group of one peptide bond and the carboxyl group of another peptide bond
the anticodon of a properly formed aminoacyl tRNA
What molecule/feature ensures that the correct amino acid is added with reading of a specific codon during translation? A) the anticodon of a properly formed aminoacyl tRNA B) the methyl-guanosine cap of a properly modified mRNA C) the poly (A) tail of a properly modified mRNA D) the twisting number of a properly supercoiled DNA
it is taken to the liver and converted back to pyruvate
When an individual is exercising heavily and when the muscle becomes oxygen-deprived, muscle cells convert pyruvate to lactate. What happens to the lactate in skeletal muscle cells? A) It produces CO2 and water. B) It is converted to NAD+. C) It is taken to the liver and converted back to pyruvate. D) It reduces FADH2 to FAD+. E) It is converted to alcohol.
negative feedback
When the body's blood glucose level rises, the pancreas secretes insulin and, as a result, the blood glucose level declines. When the blood glucose level is low, the pancreas secretes glucagon and, as a result, the blood glucose level rises. Such regulation of the blood glucose level is the result of a)protein-protein interactions. b)negative feedback. c)catalytic feedback. d)bioinformatic regulation. e) positive feedback.
Proteins
Which class of biological polymer has the greatest functional variety? a) DNA b) proteins c) polysaccharides d) RNA
secondary
Which level of protein structure do the α helix and the β pleated sheet represent? a) tertiary b) quaternary c) primary, secondary, tertiary, and quaternary d) secondary e) primary
golgi derived vesicles
Which of the following are primarily responsible for cytokinesis in plant cells but not in animal cells? A) kinetochores B) Golgi-derived vesicles C) actin and myosin D) centrioles and centromeres
replication of DNA
Which of the following does NOT occur during mitosis? A) condensation of the chromosomes B) replication of the DNA C) spindle formation D) separation of the spindle poles
homologous chromosomes of a pair are separated from each other
Which of the following happens at the conclusion of meiosis I? A) Homologous chromosomes of a pair are separated from each other. B) The chromosome number per cell remains the same. C) Sister chromatids are separated. D) Four daughter cells are formed
RrYy
Which of the following illustrates the law of independent assortment in the F1 generation of pea plants (each parent is true breeding for each trait)? A. RrYY B. rryy C. RrYy D. RRYy
It requires genetic variation, results in descent with modification, and involves differential reproductive success.
Which of the following is (are) true of natural selection? a) It requires genetic variation. b) It involves differential reproductive success. c) It requires genetic variation, results in descent with modification, and involves differential reproductive success. d) It results in descent with modification. e) It results in descent with modification and involves differential reproductive success.
it would not be able to activate and inactivate the G protein on the cytoplasmic side of the plasma membrane
Which of the following is true for the signaling system in an animal cell that lacks the ability to produce GTP? A) It would not be able to activate and inactivate the G protein on the cytoplasmic side of the plasma membrane. B) It could activate only the epinephrine system. C) It would employ a transduction pathway directly from an external messenger. D) It would be able to carry out reception and transduction but would not be able to respond to a signal. E) It would use ATP instead of GTP to activate and inactivate the G protein on the cytoplasmic side of the plasma membrane.
photosynthesis stores energy in complex organic molecules, whereas respiration releases it
Which of the following statements best describes the relationship between photosynthesis and respiration? A) Respiration is anabolic and photosynthesis is catabolic. B) Respiration runs the biochemical pathways of photosynthesis in reverse. C) ATP molecules are produced in photosynthesis and used up in respiration. D) Photosynthesis stores energy in complex organic molecules, whereas respiration releases it. E) Photosynthesis occurs only in plants and respiration occurs only in animals.
C6H12O6 is oxidized and O2 is reduced
Which of the following statements describes the results of this reaction? C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy A) C6H12O6 is oxidized and O2 is reduced. B) O2 is oxidized and H2O is reduced. C) C6H12O6 is reduced and CO2 is oxidized. D) O2 is reduced and CO2 is oxidized. E) CO2 is reduced and O2 is oxidized.
Both are made of DNA, but bacterial chromosomes are circular, found in the cytosol, and "naked" while in eukaryotes are linear, have histones, and found in the nucleus.
Which statement is true regarding the ways in which bacterial chromosomes are similar and different from eukaryotic chromosomes? A. Both are made from DNA, but bacterial chromosomes also have histones. B. Both copy chromosomes, the cells grow, then the chromosomes are separated by mitosis; they are found in the nucleus only in eukaryotes. C. Bacterial chromosomes and eukaryotic chromosomes are similar in all respects. D. Both are made of DNA, but bacterial chromosomes are circular, found in the cytosol, and "naked" while in eukaryotes are linear, have histones, and found in the nucleus.
without a control group, there is no basis for knowing if a particular result is due to the variable being tested
Why is it important that an experiment include a control group? a) A control group assures that an experiment will be repeatable. b) Without a control group, there is no basis for knowing if a particular result is due to the variable being tested. c) The control group is the group that the researcher is in control of, the group in which the researcher predetermines the results. d) The control group provides a reserve of experimental subjects. A control group is required for the development of an "If...then" statement
