Genetics Final Graze Auburn 2019
A student uses the product rule to predict that the probability of flipping a coin twice and getting a head and then a tail is 1/4. a. true b. false
a
A test cross between a heterozygous parent and a homozygous recessive parent is expected to produce a 1:1 genotypic and phenotypic ratio. a. true b. false
a
Duplications and deletions can be detected during meiosis by the presence of extrachromosomal loops that do not pair properly with their homolog. a. True b. False
a
Give the same information for a plant with the genotype Dr/dR a. Parental: 41% Dr, 41%dR; recombinant: 9% DR, 9%dr. b. Parental: 41% DR, 41%dr; recombinant: 9% Dr, 9%dR. c. Parental: 9% DR, 9%dr; recombinant: 41% Dr, 41%dR. d. Parental: 9% Dr, 9%dR; recombinant: 41% DR, 41%dr.
a
If a strain of E. coli acquired a mutation that inactivated DNA polymerase III function, would the cell be able to replicate its DNA? Why or why not? a. The cell would not be able to replicate its DNA because it lacks the enzyme responsible for the bulk of DNA synthesis. b. The cell would not be able to replicate its DNA because it lacks the enzyme responsible for removing the RNA primer. c. The cell would be able to replicate its DNA, though at a much lower rate. d. The cell would be able to replicate its DNA because there are analogs of DNA polymerase III in the cell.
a
Mutation of consensus sequence in the lac promoter. a. Transcription is blocked. b. Transcription is constitutive.
a
Mutation of the CAP binding site of the lac promoter. a. Transcription is blocked. b. Transcription is constitutive.
a
Mutation of the lac I gene affecting the allosteric site of the protein. a. Transcription is blocked. b. Transcription is constitutive.
a
Which histone helps stabilize the solenoid structure? a. H1 b. H2A c. H2B d. H3 e. H4
a
Which of the following outcomes would be most likely if the Hershey-Chase experiments were repeated without the step involving the blender? a. Both preparations of infected bacteria would exhibit radioactivity. b. Neither preparation of infected bacteria would exhibit radioactivity. c. The phage would fail to infect bacteria. d. Both preparations of infected bacteria would contain both P32 and S35.
a
Why are genes for rRNA and tRNA considered to be genes even though they do not produce polypeptides? a. rRNA and tRNA are also gene products along with polypeptides. b. The structures of tRNA and rRNA are similar to the structures of polypeptides. c. The functions of rRNA and tRNA are similar to the functions of polypeptides. d. The statement is false; DNA sequences encoding for rRNA and tRNA are not actually genes.
a
identify the number of chromosomes present at the end of meiotic anaphase 2. a. 48 chromosomes. b. 96 chromosomes. c. 24 chromosomes. d. 12 chromosomes.
a
identify the number of chromosomes present in early prophase 1. a. 48 chromosomes, 96 chromatids. b. 48 chromosomes, 48 chromatids. c. 24 chromosomes, 48 chromatids. d. 96 chromosomes, 96 chromatids.
a
what amount of DNA is contained in each nucleus at the end of S phase? a. There are 36 chromosomes containing 6 ng of DNA. b. There are 18 chromosomes containing 1.5 ng of DNA. c. There are 36 chromosomes containing 3 ng of DNA. d. None of the above.
a
What kind of bond joins the C to the G within a single strand?
a bond
What changes would you recommend to permit expression of this eukaryotic gene in a bacterial cell? Select the four correct answers. a. I would place an intrinsic or rho-dependent termination sequence downstream of the DNA. b. I would place the DNA sequence downstream of a known bacterial promoter. c. I would place the DNA sequence upstream of a known bacterial promoter. d. I would place an enhancer sequence upstream of the eukaryotic promoter to enhance trancription. e. I would make a cDNA copy of the gene which lacks introns. f. I would add termination sequences before each intron to prevent their transcription. g. I would modify the coding sequence upstream of the ATG start codon to contain a Shine-Dalgarno sequence.
a c e g
enhancer sequence is likely to be: Check all that apply. a. located downstream of the gene it controls b. located either nearby or at great distance from the gene it controls c. located whitin a few dozens nucleotides of the gene it controls d. orientation dependent e. orientation independent f. located upstream of the gene it controls
a, b, c, e
Determine which of the following sequences and structures represent part of mature eukaryotic mRNA. Select all that apply. a. start codon b. AAUAAA c. 5′ UTR d. termination sequence e. promoter f. poly-A tail g. 3′ UTR h. stop codon i. 5′ cap j. intron
a, b, c, f, h, i
The purines are a. A b. T c. G d. C
a, c
What are the possible reasons why this eukaryotic gene is not expressed in bacteria? Select the three correct answers. a. The eukaryotic promoter is unlikely to be recognized by bacterial RNA polymerase holoenzyme. b. Eukaryotic proteins consist of amino acids not present in bacterial cells. c. The introns will not be removed from the pre-mRNA, which will result in production of an abnormal protein. d. Sequences required for efficient translation initiation in bacteria are not present. e. Base pairing differs in prokaryotic organisms, so the produced mRNA is not functional.
a, c, d
What is the role of enhancer sequences in transcription of eukaryotic genes? Select the three correct answers. a. Enhancers increase the level of transcription of genes in an orientation independent manner. b. Enhancers act as alternative promoter sequences that increase the rate of transcription. c. Enhancers increase the level of transcription of genes in a position independent manner. d. Enhancers bind transcription factors that stimulate transcription of one or more genes.
a, c, d
What are the roles and relationships between tRNA anticodon sequences and mRNA codon sequences? Select the three correct answers. a. The tRNA anticodon sequence is a three nucleotide sequence in the tRNA that base-pairs with a codon. b. The mRNA stop codon is the three nucleotide sequence in the mRNA that codes for the terminal amino acid. c. The tRNA anticodon sequence is complementary and anti-parallel to the mRNA codon sequence. d. The tRNA anticodon sequence is the part of the tRNA molecule to which an amino acid is attached. e. The tRNA anticodon sequence is a three nucleotide sequence in the tRNA that base-pairs with stop codons. f. The mRNA codon is the three nucleotide sequence in the mRNA that codes for an amino acid.
a, c, f
Identify two DNA repair mechanisms that remove UV-induced DNA lesions. Select all that apply. a. nucleotide excision b. nonhomologous end joining c. synthesis-dependent strand annealing d. photoreactivation
a, d
which goes with POLYMERASE 3? a. responsible for the bulk of synthesis of dna on the lagging strand. b. removes the rna primer c. fills in gaps with dna d. responsible for the bulk of synthesis of dna on the leading strand
a, d
Name the three processes that commonly modify eukaryotic pre-mRNA. Select the three correct answers. a. 3' polyadenylation b. initiation c. 3' capping d. 5' capping e. intron splicing f. elongation g. termination h. 5' polyadenylation
a, d, e
this picture shows what
anaphase 1 of meiosis
All of the following could result from meiosis in a pericentric inversion heterozygote in which a single crossover occurred within the inversion loop except a _______. a. completely normal chromosome b. chromosome with two centromeres c. chromosome with some deleted regions d. chromosome with some duplicated regions
b
Are bacterial and eukaryotic gene transcripts modified before translation? a. Only bacterial transcripts are modified before translation, eukaryotic transcripts are not. b. Only eukaryotic transcripts are modified before translation, bacterial transcripts are not. c. Both bacterial and eukaryotic transcripts are modified before translation. d. Both bacterial and eukaryotic transcripts are not modified before translation.
b
If a dihybrid cross is performed, the expected genotypic ratio is 9:3:3:1. a. true b. false
b
If a mutation inactivated DNA polymerase I in a strain of E. coli, would the cell be able to replicate its DNA? If so, what kind of abnormalities would you expect to find in the cell? a. The cell would be able to replicate its DNA. The mutation will result in a newly replicated RNA chain instead of a DNA chain. b. The cell would be able to replicate its DNA. The mutation will result in newly replicated DNA containing small segments of RNA. c. The cell would be able to replicate its DNA. The mutation would not cause any abnormalities. d. The cell would not be able to replicate its DNA.
b
If a woman is heterozygous for albinism, an autosomal recessive condition that results in the absence of skin pigment, the proportion of her gametes carrying the allele that allows pigment expression is expected to be 75%. a. true b. false
b
Inversion loops do NOT form during meiosis in paracentric inversion heterozygotes. a. True b. False
b
Is nail-patella syndrome a dominant or a recessive condition? a. Nail-patella syndrome is a recessive trait. b. Nail-patella syndrome is a dominant trait.
b
Mutation of the lac I gene affecting the DNA-binding site of the protein. a. Transcription is blocked. b. Transcription is constitutive.
b
Mutation of the repressor binding site on the operator sequence. a. Transcription is blocked. b. Transcription is constitutive.
b
Part complete Reciprocal crosses that produce identical results demonstrate that a strain is pure-breeding. a. true b. false
b
Recall Mendel's law of segregation for autosomal alleles D and d and consider the behavior of homologous chromosomes in meiosis. Suppose a crossover occurs between the homologous chromosomes. At what stage or stages of M phase could alleles D and d segregate? a. prophase b. anaphase I or II c. metaphase I d. telophase I or II
b
The Hershey and Chase experiments involved the preparation of two different types of radioactively labeled phage. Which of the following best explains why two preparations were required? a. The bacteriophage used in the experiments was a T2 phage. b. It was necessary that each of the two phage components, DNA and protein, be identifiable upon recovery at the end of the experiment. c. Establishing the identity of the genetic material required observation of two phage generations. d. Each scientist had his own method for labeling phage, so each conducted the same experiment using a different isotope.
b
The outcome of a trihybrid cross is predicted by the law of segregation. a. true b. false
b
The second order of chromatin packing occurs when nucleosomes coil together to form a fiber that is 300 nm in diameter. a. True b. False
b
What is the first order of chromatin packing? a. Looping of 300‑nm fibers b. Coiling around nucleosomes c. Formation of a solenoid d. Formation of a 300‑nm fiber
b
What kind of lesion does UV energy cause? a. deamination b. pyrimidine dimerization c. frameshift mutation d. induction of DNA strand breaks
b
What makes up the protein component of a nucleosome core? a. One tetramer of histone proteins b. Two tetramers of histone proteins c. Eight different histone proteins d. Histone H1 protein
b
Which of the following statements best represents the central conclusion of the Hershey-Chase experiments? a. When radioactive sulfur is supplied in a growth medium, it is primarily DNA that incorporates radioactive label. b. DNA is the identity of the hereditary material in phage T2. c. Phage T2 is capable of replicating within a bacterial host. d. Some viruses can infect bacteria.
b
which goes with POLYMERASE 1? a. responsible for the bulk of synthesis of dna on the lagging strand. b. removes the rna primer c. fills in gaps with dna d. responsible for the bulk of synthesis of dna on the leading strand
b, c
Speculate about why enhancers are not part of transcription of bacterial genes. Select the three correct answers. a. The high level of mutation in bacterial genomes would likely alter these conservative sequences rendering them nonfunctional. b. There is little to no intergenic space on bacterial chromosomes, which makes long-range-acting enhancer sequences unnecessary. c. Bacterial operons make coordinate regulation of protein synthesis by enhancers unnecessary. d. Enhancers often provide a mechanism for cell-specific transcription of genes, and most bacteria lack differentiated cell types. e. Bacteria mostly regulate gene expression at the level of translation, making transcription enhancers unnecessary.
b, c, d
What are the roles and relationships between tRNA synthetases and tRNA molecules? Select the four correct answers. a. tRNA synthetases are enzymes that participate in transcription of tRNA genes and splicing of premature tRNA molecules into functional tRNAs. b. tRNA synthetases are enzymes that "charge tRNAs" by catalyzing the covalent attachment of an amino acid to the 3' end of the tRNA. c. There are 20 different tRNA synthetases, one for each amino acid. d. One tRNA synthetase charges all the tRNAs that carry the cognate amino acids. e. One tRNA synthetase charges all the tRNAs that carry any amino acid. f. There are 61 different tRNA synthetases, one for each tRNA. tRNAs act as peptidyl transferases catalyzing peptide bond formation between the amino acid at the P site and the newly recruited amino acid at the A site. g. tRNAs are the adaptor molecules that convert the sequence of codons in mRNAs into the sequence of amino acids in polypeptides.
b, c, d, g
The pyrimidines are a. A b. T c. G d. C
b, d
What kind of bonds join the C in one strand to the G in the complementary strand?
bonds
A plant with the genotype DR/dr produces gametes. Identify gamete genotypes, label parental and recombinant gametes, and give the frequency of each gamete genotype. a. Parental: 9% DR, 9%dr; recombinant: 41% Dr, 41%dR. b. Parental: 41% Dr, 41%dR; recombinant: 9% DR, 9%dr. c. Parental: 41% DR, 41%dr; recombinant: 9% Dr, 9%dR. d. Parental: 9% Dr, 9%dR; recombinant: 41% DR, 41%dr.
c
During which stage of M phase do these two alleles segregate from one another? (Assuming no crossovers between homologs). a. telophase I b. prophase I c. anaphase I d. metaphase I
c
How does RNA participate in DNA replication? a. RNA prevents reannealling of separated DNA strands. b. RNA transports free nucleotide triphosphates to the phosphodiester bond formation site of DNA polymerase III. c. RNA serves as a primer for elongation by DNA polymerase. d. RNA relaxes supercoilling of DNA strands.
c
What general role does acetylation of histone protein amino acids play in the transcription of eukaryotic genes? a. Histone acetylation events are most often associated with transcription proofreading. b. Histone acetylation events are most often associated with transcription termination. c. Histone acetylation events are most often associated with transcription activation. d. Histone acetylation events are most often associated with transcription repression.
c
What is a gene? a. A gene is an RNA, which codes for translation of a protein. b. A gene is the unit of heritage, mutation, recombination and function. c. A gene is a segment of DNA that contains the information for transcription of an RNA. d. A gene is a structural protein that defines a heritable trait.
c
What is a reference genome? a. A reference genome is the initial genome sequence of a species, which is typically determined using DNA from a large number of individual members of the species. b. A reference genome is the whole genome sequence of a species, which is typically determined using DNA from a few individual members of the species. c. A reference genome is the initial genome sequence of a species, which is typically determined using DNA from a few individual members of the species. d. A reference genome is the whole genome sequence of a species, which is typically determined using DNA from a large number of individual members of the species.
c
What phenotype would be expected in balanced translocation heterozygotes in the absence of position effects? a. Normal, even though they have too much genetic material b. Abnormal, because they have too much genetic material c. Normal, because they have a normal amount of genetic material d. Abnormal, because they lack some genetic material
c
Which of the following arrangements would yield the greatest reduction in gamete viability? a. An inversion homozygote for a small inversion b. An inversion homozygote for a large inversion c. An inversion heterozygote for a large inversion d. An inversion heterozygote for a small inversion
c
Which of the following syndromes is not paired with its causative chromosomal aberration? a. Cri du chat syndrome - deletion b. Huntington disease - duplication c. Fragile X syndrome - deletion d. Down syndrome - Robertsonian translocation
c
identify the number of chromosomes present in early mitotic prophase. a. 48 chromosomes, 48 chromatids. b. 24 chromosomes, 24 chromatids. c. 48 chromosomes, 96 chromatids. d. 24 chromosomes, 48 chromatids.
c
what describes the end of mitotic telophase? a. 24 chromosomes: 23 autosomes, 1 sex chromosomes,each chromosome will be composed of a single chromatid. b. 24 chromosomes: 23 autosomes, 1 sex chromosomes,each chromosome will be composed of a double chromatid. c. 48 chromosomes: 46 autosomes, 2 sex chromosomes,each chromosome will be composed of a single chromatid. d. 48 chromosomes: 46 autosomes, 2 sex chromosomes,each chromosome will be composed of a double chromatid.
c
What is a compound that interacts with another protein or compound to form an active repressor?
corepressor
Choose the correct definition of epigenetics. a. Epigenetic refers to heritable traits encoded by extrachromosomal genes (such as those of mitochondrial genes). b. Epigenetic refers to heritable patterns of a gene's transcription activity. c. Epigenetic refers to heritable traits, the expression of which is strongly dependent on environmental factors. d. Epigenetic refers to heritable states of chromatin structure.
d
Which of the following components would be required in a bacterial expression vector, but NOT in a bacterial cloning vector? a. Multi-cloning site b. Bacterial origin of replication c. Bacterial selectable marker d. Bacterial promoter
d
identify the number of chromosomes present in meiotic metaphase 1. a. 24 chromosomes, 24 chromatids. b. 48 chromosomes, 48 chromatids. c. 24 chromosomes, 48 chromatids. d. 48 chromosomes, 96 chromatids.
d
identify the number of chromosomes present in mitotic metaphase. a. 96 chromosomes, 96 chromatids. b. 48 chromosomes, 48 chromatids. c. 24 chromosomes, 48 chromatids. d. 48 chromosomes, 96 chromatids.
d
promoter sequence is likely to be: Check all that apply. a. located within a few dozens nucleotides of the gene it controls b. orientation independent c. located upstream of the gene it controls d. located downstream of the gene it controls e. located either nearby or at great distance from the gene it controls f. orientation dependent
d, f
the beginning of prophase in mitosis and prophase 1 in meiosis both follow completion of ______ phase and _____ phase.
g1, s
what is a compound that induces or activates transcription, such as lactose?
inducer
Transition is described as a purine to purine / pyrimidine to pyrimidine or _______ to ______.
like, like
_________ is a population genetics term referring to the nonrandom association of specific alleles of two or more genes in a population.
linkage disequilibrium
DNA polymerase III determines which free ________ is ________ to the base being copied.
nucleotide triphosphate, complementary
What is a DNA sequence that binds a regulatory protein?
operator
Transversion is described as pyrimidine to purine / purine to pyrimidine or __________.
opposites
DNA polymerase III catalyzes bond formation between the _____ of the incoming ______ and the ______ group of the last nucleotide added to the strand.
phosphodiester, 5' phosphate, nucleotide triphosphate, 3' hydroxyl
What is a DNA sequence that binds RNA polymerase and regulates transcription?
promotor
what is a regulatory protein that may bind DNA to inhibit transcription?
repressor
