Bio Test 3 Review
Quaking aspen can send out underground stems for asexual reproduction. Sexual reproduction is not as common, but when it does happen, the haploid gametes have 19 chromosomes. How many chromosomes are in the cells of the underground stems? A. 38 B. 19 C. 9 D. 10
A. 38
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 21 sets of 3 B. 63 chromosomes in 31 1/2 pairs C. 21 chromosomes pairs and 21 unique chromosomes D. 63 chromosomes, each with three chromatids
A. 63 chromosomes in 21 sets of 3
The following is a map of four genes on a chromosome Between which 2 genes would you expect the highest frequency of recombination? A. E and G B. A and G C. A and E D. A and W
A. A and G
A particular triplet of bases in the coding sequence of DNA is AAA. The anticodon on the tRNA that binds the mRNA codon is: A. AAA B. UUU C. TTT D. UUA
A. AAA
Which one of the following, if missing, would usually prevent translation from starting? A. AUG codon B. 5' cap C. poly-A tail D. exon
A. AUG codon
CAP is said to be responsible for positive regulation of the lac operon because: A. CAP bound to the CAP-binding site increases the frequency of transcription initiation B. CAP prevents binding of the repressor to the operator C. CAP bind cAMP D. CAP binds to the CAP-binding site
A. CAP bound to the CAP-binding site increases the frequency of transcription initiation
a sexually reproducing animal has 2 unlinked genes, one for head shape (H) and one for tail length (T). its genotype is HhTt. which of the following genotypes is possible in a gamete from this organism? A. HT B. Hh C. T D. HhTt
A. HT
What is the definition of one map unit? A. a 1% frequency of recombination between 2 genes B. the recombination frequency between 2 genes assorting independently C. the physical distance between two linked genes D. 1 nanometer of distance between 2 genes
A. a 1% frequency of recombination between 2 genes
A ribosome is: A. an RNA with catalytic activity B. an enzyme that synthesizes RNA as part of the transcription process C. an enzyme that catalyzes the association between the large and small ribosomal subunits D. a catalyst that uses RNA as a substrate
A. an RNA with catalytic activity
In the yeast signal transduction pathway, after both types of mating cells have released the mating factors and the factors have bound to specific receptors on the correct cells: A. binding induces changes in the cells that lead to cell fusion B. the cells then produce the a factor and the á factor C. one cell nucleus binds the mating factors and produces a new nucleus in the opposite cell D. the cell membranes fall apart, releasing the mating factors that lead to new yeast cells
A. binding induces changes in the cells that lead to cell fusion
In general, a signal transmitted vie phosphorylation of a series of proteins: A. brings a conformational change to each protein B. requires binding of a hormone to a cytosol receptor C. cannot occur in yeasts because they lack protein phosphatases D. requires phosphorylase activity E. allows target cells to change their shape and therefore their activity
A. brings a conformational change to each protein
A mutation that inactivates the regulatory gene of a repressible operon in an E. coli cell would result in: A. continuous transcription of the structural gene controlled by that regulator B. continuous translation of the mRNA because of alteration of its structure C. irreversible binding of the repressor to the operator D. complete inhibition of transcription of the structural gene controlled by that regulator
A. continuous transcription of the structural gene controlled by that regulator
DNA methylation and histone acetylation are examples of: A. epigenetic phenomena B. chromosomal rearrangements C. genetic mutation D. translocation
A. epigenetic phenomena
Eukaryotic telomeres replicate differently than the rest of the chromosome. This is a consequence of which of the following? A. gaps left at the 5' end of the lagging strand B. DNA polymerase that cannot replicate the leading strand template to its 5' end C. the evolution of telomerase enzyme D. gaps left at the 3' end of the lagging strand because of the need for a primer
A. gaps left at the 5' end of the lagging strand
A signal peptide: A. helps target a protein to the ER B. signals the initiation of transcription C. directs an mRNA molecule into the cisternal space of the ER D. terminated translation of messenger RNA
A. helps target a protein to the ER
Paracine signaling: A. involved secreting cells acting on nearby target cells by discarding a local regulator into the extracellular fluid B. requires nerve cells to release a neurotransmitter into the synapse C. occurs only in paracrine yeast cells D. has been found in plants but not animals
A. involved secreting cells acting on nearby target cells by discarding a local regulator into the extracellular fluid
What would be 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 C. it would be able to carry out reception and transduction, but would not be able to respond to a signal D. only A and C are true E. A, B, and C are true
A. it would not be able to activate and inactivate the G protein on the cytoplasmic side of the plasma membrane
Crossing over normally takes place during which of the following processes? A. meiosis I B. meiosis II C. mitosis and meiosis II D. mitosis
A. meiosis I
Asexual reproduction occurs during: A. mitosis B. chromosome exchange between organisms of different species C. meiosis D. fertilization
A. mitosis
The toxin of Vibrio cholerae causes profuse diarrhea because it A. modifies a G protein involved in regulating salt and water secretion B. decreases the cytosolic concentration of calcium ions, making the cells hypotonic to the intestinal cells C. binds with adenylyl cyclase and triggers the formation of cAMP D. signals inositol triphosphate to become a second messenger for the release of calcium E. modifies calmodulin and activates a cascade of protein kinases
A. modifies a G protein involved in regulating salt and water secretion
Replication in prokaryotes differs from replication in eukaryotes for which of the following reasons? A. prokaryotic chromosomes have a single origin of replication, whereas eukaryotic chromosomes have many B. the rate of elongation during DNA replication is slower in prokaryotes than in eukaryotes C. prokaryotic chromosomes have histones, whereas eukaryotic chromosomes do not D. prokaryotes produce Okazaki fragments during DNA replication, but eukaryotes do not
A. prokaryotic chromosomes have a single origin of replication, whereas eukaryotic chromosomes have many
What is meant by the description "antiparallel" regarding the strands that make up DNA? A. the 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand B. one strand contains only purines and the other contains only pyrimidines C. base pairings create unequal spacing between the two DNA strands D. the twisting nature of FNA creates nonparallel strands
A. the 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand
A couple has a child with Down syndrome. The mother is 39 years old at the time of delivery. Which of the following is the most probably cause of the child's condition? A. the mother most likely underwent nondisjunction during gamete production B. the mother had a chromosomal duplication C. the woman inherited this tendency from her parents D. one member of the couple underwent nondisjunction in somatic cell production
A. the mother most likely underwent nondisjunction during gamete production
The following questions refers to the pedigree chart in the figure below 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 genotype of individual II-5? A. ww B. Ww C. ww or Ww D. WW
A. ww
Among the newly discovered small noncoding RNAs, one type reestablishes methylation patterns during gamete formation and block expression of some transposons. These are known as A) miRNA B) piRNA C) snRNA D) siRNA
B) piRNA
A recessive allele on the X chromosome is responsible for red-green color blindness in humans. A woman with normal vision whose father is color blind marries a color-blind male. What is the probability that this couple's first son will be colorblind? A. 3/4 B. 1/2 C. 2/3 D. 1/4
B. 1/2
Black fur in mice (B) is dominant to brown fur (b). Short tails (T) are dominant to long tails (t). What fraction of the progeny of crosses BbTt × BBtt will be expected to have black fur and long tails? A. 1/16 B. 1/2 C. 3/8 D. 9/16
B. 1/2
Skin color in a certain species of fish is inherited via a single gene with four different alleles. How many different types of gametes would be possible in this system? A. 8 B. 4 C. 16 D. 2
B. 4
A woman who has blood type A positive has a daughter who is type O positive and a son who is type B negative. Rn positive is a trait that shows simple dominance over Rh negative. Which of the following is a possible phenotype for the father? A. A negative B. B positive C. O negative D. AB negative
B. B positive
A new DNA strand elongates only in the 5' to 3' direction because: A. a replication must progress toward the replication fork B. DNA polymerase can add nucleotides only to the free 3' end C. the polarity of the DNA molecule prevents addition of nucleotides at the 3' end D. DNA polymerase begins adding nucleotides at the 5' end of the template
B. DNA polymerase can add nucleotides only to the free 3' end
You have isolated DNA from three different cell types of the same organism, determined the relative DNA content for each type, and plotted the results on the graph shown in the figure below. Refer to the graph to answer the following question(s). Which sample might represent an animal cell in the G2 phase of the cell cycle? A. I B. II C. III D. both I and II
B. II
The DNA of telomeres has been highly conserved throughout the evolution of eukaryotes. This most likely reflects: A. that new mutations in telomeres have been advantageous B. a critical function of telomeres C. continued evolution of telomeres D. the low frequency of mutations occurring in this DNA
B. a critical function of telomeres
For a science fair project, two students decided to repeat the Hershey and Chase experiment, with modifications. They decided to label the nitrogen of the DNA, rather than the phosphate. They reasoned that each nucleotide has only one phosphate and two to five nitrogens. Thus, labeling the nitrogens would provide a stronger signal than labeling the phosphates. Why won't this experiment work? A. radioactive nitrogen has a half-life of 100,000 years, and the material would be too dangerous for too long B. amino acids (and thus proteins) also have nitrogen atoms; thus, the radioactivity would not distinguish between DNA and proteins C. although there are more nitrogens in a nucleotide, labeled phosphates actually have sixteen extra neutrons; therefore, they are more radioactive D. there is no radioactive isotope of nitrogen
B. amino acids (and thus proteins) also have nitrogen atoms; thus, the radioactivity would not distinguish between DNA and proteins
Testosterone functions inside a cell by: A. acting as a signal receptor that activates ion-channel proteins B. binding with a receptor protein that enters the nucleus activates specific genes C. acting as a steroid signal receptor that activates ion-channel proteins D. they control which genes are expressed E. they are needed to regulate the synthesis of lipids in the cytoplasm
B. binding with a receptor protein that enters the nucleus activates specific genes
Membrane receptors that attach phosphates to specific amino acids in proteins are: A. not found in humans B. called receptor tyrosine-kinases C. a class of GTP G-protein signal receptors D. associated with several bacterial diseases in humans E. important in yeast mating factors that contain amino acids
B. called receptor tyrosine-kinases
Alternative RNA splicing: A. increases the rate of transcription B. can allow the production of proteins of different sizes and functions from a single mRNA C. is a mechanism for increasing the rate of translation D. can allow the production of similar proteins from different RNAs
B. can allow the production of proteins of different sizes and functions from a single mRNA
A nonreciprocal crossover causes which of the following products? A. deletion only B. deletion and duplication C. nondisjunction D. duplication only
B. deletion and duplication
Hydrangea plants of the same genotype are planted in a large flower garden. Some of the plants produce blue flowers and others pink flowers. This can be best explained by which of the following? A. the alleles being co-dominant B. environmental factors such as soil pH C. the allele for blue hydrangea being completely dominant D. the knowledge that multiple alleles are involved
B. environmental factors such as soil pH
Mitochondrial DNA is primarily involved in coding for proteins needed for protein complexes of the electron transport chain and ATP synthase. Therefore, mutations in mitochondrial genes would most affect: A. DNA synthesis in cells of the immune system B. generation of ATP in muscle cells C. the movement of oxygen into erythrocytes D. the storage of urine in the urinary bladder
B. generation of ATP in muscle cells
The human X and Y chromosomes: A. are called autosomes B. include fees that determine and individual's sex C. are the same size and have the same number of genes D. are both present in every somatic cell of males and females
B. include genes that determine an individual's sex
A small molecule that specifically binds to another molecule, usually a larger one: A. is called a signal transducer B. is called a ligand C. is called a polymer D. seldom is involved in hormonal signaling E. usually terminates a signal reception
B. is called a ligand
At which stage of mitosis are chromosomes photographed in the preparation of a karyotype? A. interphase B. metaphase C. anaphase D. prophase
B. metaphase
What does it mean when we say the genetic code is redundant? A. the genetic code is universal (the same for all organisms) B. more than one codon can specify the addition of the same amino acid C. the genetic code is different for different domains of organisms D. a single codon can specify the addition of more than one amino acid
B. more than one codon can specify the addition of the same amino acid
Replication in prokaryotes differs from replication in eurkaryotes for which of the following reasons: A. Prokaryotes produce Okazaki fragments during DNA replication, but eukaryotes do not B. prokaryotic chromosomes have a single origin of replication, whereas eukaryotic chromosomes have many C. prokaryotic chromosomes have histones, whereas eukaryotic chromosomes do not D. the rate of elongation during DNA replication is slower in prokaryotes than in eukaryotes
B. prokaryotic chromosomes have a single origin of replication, whereas eukaryotic chromosomes have many
From the perspective of the cell receiving the message, the three stages of cell signaling are: A. the paracrine, local, and synaptic stages B. signal reception, signal transduction, and cellular response C. signal reception, nucleus disintegration, and new cell generation D. the alpha, beta, and gamma stages
B. signal reception, signal transduction, and cellular response
The process of transduction usually begins: A. when the chemical signal is released from the alpha cell B. signal reception, signal transduction, and cellular response C. signal reception, nucleus disintegration, and new cell generation D. the alpha, beta, and gamma stages E. signal reception, cellular response, and cell division
B. signal reception, signal transduction, and cellular response
Which of the following help(s) to hold the DNA strands apart while they are being replicated? A. DNA polymerase B. single-strand DNA binding proteins C. ligase D. primase
B. single-strand DNA binding
Which is true of transcription factors? A. they regulate the synthesis of DNA in response to a signal B. some transcribe ATP into cAMP C. they initiate the epinephrine response in animal cells D. they control which genes are expressed E. they are needed to regulate the synthesis of lipids in the cytoplasm
B. some transcribe ATP into cAMP
Which of the following are chemical messengers that pass through the plasma membrane of cells and have receptors molecules in the cytoplasm? A. insulin B. testosterone C. cAMP D. epinephrine
B. testosterone
Which of the following defines a genome? A. the complete set of an organism's polypeptides B. the complete set of an organism's genes and other DNA sequences C. a karyotype D. the complete set of a species' polypeptides
B. the complete set of an organism's genes and other DNA sequences
Which of the following is an example of monosomy? A. trisomy X B. turner's syndrome C. Klinefelter's syndrome D. down syndrome
B. turner's syndrome
Somatic cells of roundworms have four individual chromosomes per cell. How many chromosomes would you expect to find in an ovum from a roundworm? A. four B. two C. eight D. a diploid number
B. two
Which of the following provides an example of epistasis? A) Recessive genotypes for each of two genes (aabb) results in an albino corn snake. B) In cacti, there are several genes for the type of spines C) In rabbits and many other mammals, one genotype (cc) prevents any fur color from developing. D) In Drosophila (fruit flies), white eyes can be due to an X-linked gene or to a combination of other genes.
C) In rabbits and many other mammals, one genotype (cc) prevents any fur color from developing.
Mendel accounted for the observation that traits which had disappeared in the F1 generation reappeared in the F2 generation by proposing that A) new mutations were frequently generated in the F2 progeny, "reinventing" traits that had been lost in the F1. B) the mechanism controlling the appearance of traits was different between the F1 and the F2 plants. C) traits can be dominant or recessive, and the recessive traits were obscured by the dominant ones in the F1. D) the traits were lost in the F1 due to dominance of the parental traits.
C) traits can be dominant or recessive, and the recessive traits were obscured by the dominant ones in the F1.
Albinism is an autosomal (not sex-linked) recessive trait. A man and woman are both of normal pigmentation, but both have one parent who is albino (without melanin pigmentation). What is the probability that their first child will be an albino? A. 0 B) 1 C) 1/4 D. 1/2
C. 1/4
If cell X enters meiosis, and nondisjunction of one chromosome occurs in one of its daughter cells during meiosis II, what will be the result at the completion of meiosis? A. all the gametes descend from cell X will be diploid B. two of the four gametes descended from cell X will be haploid, and two will be diploid C. 1/4 of the gametes descended from cell X will be n+1, 1/4 will be n-1, and 1/2 will be n D. half of the gametes descended from cell X will be n+1, and half will be n-1
C. 1/4 of the gametes descended from cell X will be n+1, 1/4 will be n-1, and 1/2 will be n
A particular triplet of bases in the template strand of DNA is 5' AGT 3'. The corresponding codon for the mRNA transcribed is: A. 3' ACU 5' B. 5' TCA 3' C. 3' UCA 5' D. 3' UGA 5'
C. 3' UCA 5'
The following questions refer to this table of codons A possible sequence of nucleotides in the template strand of DNA that would code for the polypeptide sequence phe-leu-ile-val would be: A. 3'AAA-AAt-ATA-ACA 5' B. 5'AUG-CTG-CAG-TAT 3' C. 3'AAA-GAA-TAA-CAA 5' D. 5'TTG-CTA-CAG-TAG 3'
C. 3'AAA-GAA-TAA-CAA 5'
A particular triplet of bases in the template strand of DNA is 5', AGT 3'. The corresponding codon for the mRNA transcribed is: A. 5'TCA3' B. 3'ACU5' C. 3'UCA5' D. 3'UCA5'
C. 3'UCA5'
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. 3/16 B. 1/16 C. 3/8 D. 1/4
C. 3/8
Which of the following is a correct association? A. kinase activity and the addition of a tyrosine B. phosphodiesterase activity and the removal of phosphate groups C. GTPase activity and hydrolysis of GTP to GDP D. phosphorylase activity and the catabolism of glucose
C. GTPase activity and hydrolysis of GTP to GDP
What do we mean when we use the terms monohybrid cross and dihybrid cross? A. a monohybrid cross is performed for one generation, whereas a dihybrid cross is performed for two generation B. a monohybrid cross involves a single parent, whereas a dihybrid cross involved two parents C. a dihybrid cross involves organisms that are heterozygous for two characters that are being studied, and a monohybrid cross involves organisms that are heterozygous for only one character being studied D. a monohybrid cross results in a 9:3:3:1 ratio whereas a dihybrid cross gives a 3:1 ratio
C. a dihybrid cross involves organisms that are heterozygous for two characters that are being studied, and a monohybrid cross involves organisms that are heterozygous for only one character being studied
Caffeine is an inhibitor of phosphodiesterase. Therefore, the cells of a person who has recently consumed coffee would have increased levels of: A. phosphorylated proteins B. GTP C. cAMP D. adenylyl cyclase
C. cAMP
Alternative RNA splicing: A. increases the rate of transcription B. can allow the production of similar proteins from different RNAs C. can allow the production of proteins of different sizes and functions from a single mRNA D. is a mechanism for increasing the rate of translation
C. can allow the production of proteins of different sizes and functions from a single mRNA
Codons are three-base sequences that specify the addition of a single amino acid. How do eukaryotic codons and prokaryotic codons compare? A. prokaryotic codons usually contain different bases than those of eukaryotes B. the translation of codons is mediated by tRNAs in eukaryotes, but translation requires no intermediate molecules such as tRNAs in prokaryotes C. codons are a nearly universal language among all organisms D. prokaryotic codons usually specify different amino acids than those of eukaryotes
C. codons are a nearly universal language among all organisms
Codons are three-based sequences that specify the addition of a single amino acid. How do eukaryotic codons and prokaryotic codons compare? A. prokaryotic codons usually contain different bases that those of eukaryotes B. the translation of codons is mediated by tRNAs in eukaryotes, but translation requires no intermediate molecules such as tRNAs in prokaryotes C. codons are nearly universal language among all organisms D. prokaryotic codons usually specify different amino acids than those of eukaryotes
C. codons are nearly universal language among all organisms
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 is identical in content to another cell formed from the same meiosis I event B. It has half the chromosomes but twice the DNA of the originating cell C. it has half the amount of DNA as the cell that began meiosis D. it has one-fourth the DNA and one-half the chromosomes as the originating cell
C. it has half the amount of DNA as the cell that began meiosis
In a human karyotype, chromosomes are arranged in 23 pairs. If we choose one of these pairs, such as pair 14, which of the following do the 2 chromosomes of the pair have in common? A. length, centromere position, and staining pattern only B. length and position of the centromere only C. length, centromere position, staining patter, and traits coded for by their genes D. they have nothing in common except that they are X-shaped
C. length, centromere position, staining patter, and traits coded for by their genes
Which of the following is the meaning of the chromosome theory of inheritance as expressed in the early 20th century? A. natural selection acts o certain chromosome arrays rather than on genes B. individuals inherit particular chromosomes attached to genes C. mendelian genes are at specific loci on the chromosome and, in turn, segregate during meiosis D. no more than a single pair of chromosomes can be found in a healthy normal cell
C. mendelian genes are at specific loci on the chromosome and, in turn, segregate during meiosis
When a cell releases a signal molecule into the environment and a number of cells in the immediate vicinity respond, this type of signaling is A. typical of hormones B. autocrine signaling C. paracrine signaling D. endocrine signaling E. synaptic signaling
C. paracrine signaling
Adenylyl cyclase has the opposite effect of which of the following? A. protein kinase B. protein phosphatase C. phosphodiesterase D. phosphorylase
C. phosphodiesterase
The general name for an enzyme that transfers phosphate groups from ATP to a protein is A. phosphorylase B. phosphatase C. protein kinase D. ATPase E. protease
C. protein kinase
What is the function of topoisomerase? A. elongating new DNA at a replication fork by adding nucleotides to the existing chain B. unwinding of the double helix C. relieving strain in the DNA ahead of the replication fork D. stabilizing single-stranded DNA at the replication fork
C. relieving strain in the DNA ahead of the replication fork
The reasons for differences in the sets of proteins expressed in a nerve and a pancreatic cell of the same individual is that nerve and pancreatic cells contain different: A. promoters B. genes C. set of regulatory proteins D. regulatory sequences
C. sets of regulatory proteins
Which of the following statements is true of linkage? A. all of the traits that Mendel studied- seed color, pod shape, flower color, and others- are due to genes linked on the same chromosome B. the observed frequency of recombination of two genes that are far apart from each other has a maximum value of 100% C. the closer two genes are on a chromosome, the lower the probability that a crossover will occur between them D. linked genes are found on different chromosomes
C. the closer two genes are on a chromosome, the lower the probability that a crossover will occur between them
Up to 60% of all medicines used today exert their effects by influencing what structures in the cell membrane? A. tyrosine-kinases receptors B. ligand-gated ion channel receptors C. growth factors D. G proteins E. cholesterol
D. G proteins
Eukaryotic sexual life cycles show tremendous variation. Of the following elements, which do all sexual life cycles have in common? I. Alternation of generations II. Meiosis III. Fertilization IV. Gametes V. Spores A. I, II, and IV B. II, IV, and V C. I, II, III, IV, and V D. II, III, and IV
D. II, III, and IV
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
D. XNXn and XNY
A man who carries an allele of an X-linked gene will pass it on to: A. all of his children B. all of his sons C. half of his daughters D. all of his daughters
D. all of his daughters
How do we describe transformation on in bacteria? A. the creation of a strand of DNA from an RNA molecule B. the creation of a strand of RNA from a DNA molecule C. the infection of cells by a phage DNA molecule D. assimilation of external DNA into a cell
D. assimilation of external DNA into a cell
A lack of which molecule would result in a cell's inability to "turn off" genes? A. promoter B. inducer C. operon D. corepressor
D. corepressor
At puberty, an adolescent female body changes in both structure and function of several organ systems, primarily under the influence of changing concentrations of estrogens and other steroid hormones. How can one hormone, such as estrogen, mediate so many effects? A. estrogen is produced in very large concentration and therefore diffuses widely B. estrogen has specific receptors inside several cell types, but each cell responds in the same way to its binding C. estrogen is kept away from the surface of any cells not able to bind it at the surface D. estrogen binds to specific receptors inside many kinds of cells, each of which have different responses to its binding
D. estrogen binds to specific receptors inside many kinds of cells, each of which have different responses to its binding
Mitochondrial DNA is primarily involved in coding for proteins needed for protein complexes of the electron transport chain and ATP synthase. Therefore, mutations in mitochondrial genes would most affect: A. the storage of urine in the urinary bladder B. the movement of oxygen into erythrocytes C. DNA synthesis in cells of the immune system D. generation of ATP in muscle cells
D. generation of ATP in muscle cells
After telophase I of meiosis, the chromosomal makeup of each daughter cell is A. diploid, and the chromosomes are composed of a single chromatid. B. diploid, and the chromosomes are composed of two chromatids. C. haploid, and the chromosomes are composed of a single chromatid. D. haploid, and the chromosomes are composed of two chromatids.
D. haploid, and the chromosomes are composed of two chromatids.
Synaptic signaling between adjacent neurons is like hormone signaling in which of the following ways? A. it sends its signal molecules through the blood B. it sends it signals molecules quite a distance C. it requires calcium ions D. it requires binding of a signaling molecule to a receptor E. it persists over a long period
D. it requires binding of a signaling molecule to a receptor
Codons are part of the molecular structure of: A. rRNA B. tRNA C. a protein D. mRNA
D. mRNA
What does it mean when we say the genetic code is redundant? A. the genetic code is universal (the same for all organisms) B. the genetic code is different for different domains of organisms C. a single codon can specify the addition of more than one amino acid D. more than one codon can specify the addition of the same amino acid
D. more than one codon can specify the addition of the same amino acid
What is an adaptive advantage of recombination between linked genes? A. recombination is required for independent assortment B. recombination must occur or genes will not assort independently C. the forces on the cell during meiosis II results in recombination D. new allele combinations are acted upon by natural selection
D. new allele combinations are acted upon by natural selection
A man who is an achondroplastic dwarf with normal vision marries a color-blind woman of normal height. The man's father was six feet tall, and both the woman's parents were of average height. Achondroplastic dwarfism is autosomal dominant, and red-green color blindness is X-linked recessive. How many of their daughters might be expected to be color-blind dwarfs? A. one out of four B. half C. three out of four D. none
D. none
In E. coli, to repair a thymine dimer by nucleotide excision repair, in which order do the necessary enzymes act? A. helices, DNA polymerase I, DNA ligase B. nuclease, DNA polymerase III, RNA primase C. DNA ligase, nuclease, helicase D. nuclease, DNA polymerase I, DNA ligase
D. nuclease, DNA polymerase I, DNA ligase
Chemical signal pathways: A. operate in animals, but not in plants B. are absent in bacteria, but are plentiful in yeast C. involve the release of hormones into the blood D. often involve the binding of signal molecules to a protein on the surface of a target cell E. use hydrophilic molecules to activate enzymes
D. often involve the binding of signal molecules to a protein on the surface of a target cell
Semiconservative replication involves a template? What is the template? A. DNA polymerase B. an RNA molecule C. single-stranded binding proteins D. one strand of the DNA molecule
D. one strand of the DNA molecule
An inhibitor of which of the following could be used to block the release of calcium from the endoplasmic reticulum? A. tyrosine kinases B. serine/threonine kinases C. phosphodiesterase D. phospholipase C
D. phospholipase C
An inhibitor of phosphodiesterase activity would have which of the following effects? A. block the response of epinephrine B. decrees the amount of cAMP in the cytoplasm C. block the activation of G proteins in response to epinephrine binding to its receptor D. prolong the effect of epinephrine by maintaining elevated cAMP levels in the cytoplasm E. block the activation of protein kinase A
D. prolong the effect of epinephrine by maintaining elevated cAMP levels in the cytoplasm
One of the major categories of receptors in the plasma membrane reacts by forming dimers, adding phosphate groups, and then activating relay proteins. Which type does this? A. G protein-linked receptor B. ligand-gated ion channels C. steroid receptors D. receptor tyrosine kinases
D. receptor tyrosine kinases
The termination phase of cell signaling requires which of the following? A. removal of the receptor B. activation of a different set of relay molecules C. converting ATP to cAMP D. reversing the binding of signal molecule to the receptor
D. reversing the binding of signal molecule to the receptor
Which of the substances below is a protein that can hold several other relay proteins as it binds to an activated membrane receptor? A. active transcription factor B. third messenger C. ligand D. scaffolding protein
D. scaffolding protein
Which of the following occurs in meiosis but not in mitosis? A. alignment of chromosomes at the equator B. condensation of chromosomes C. chromosome replication D. synapsis of chromosomes
D. synapsis of chromosomes
What could happen to the target cells in an animal that lack receptors for local regulators? A. they could compensate by receiving nutrients via an a factor B. they could develop normally in response to neurotransmitters instead C. they could divide but never reach full size D. they would not be able to multiply in response to growth factors from nearby cells
D. they would not be able to multiply in response to growth factors from nearby cells
Which of the following is (are) true of ligand-gated ion channels? A. they are important in the nervous system B. they lead to changes in sodium and calcium concentrations in cells C. they open or close in response to a chemical signal D. only A and B are true E. A, B, and C are true
E. A, B, and C are true