AP Bio Tri 2 Exam
Based on the experimental results, which of the following describes the most likely defect in muscle cells of patients with type 2 diabetes?
IRS-1 activation is reduced at high insulin concentrations.
Plates that have only ampicillin-resistant bacteria growing include which of the following?
IV only
In the pedigree above, circles represent females, squares represent males, and shaded figures represent individuals expressing a specific trait. The expression of this trait is most likely due to which of the following?
Autosomal recessive inheritance
The students choose a significance level of p=0.01p=0.01. Which of the following statements best completes the next step of the chi-square goodness-of-fit test?
The calculated chi-square value is 10.48, and the critical value is 11.35.
Which of the following is most likely to reduce the binding of the active ligand to its receptor?
A mutation in the receptor gene that causes a substitution of a charged amino acid for a nonpolar amino acid in the ligand binding site of the receptor.
Which of the following statements best describes the role of adenylyl cyclase in the epinephrine signaling pathway?
It accelerates the production of a second messenger.
Which of the following statements best describes the role of cyclic AMP in the signal transduction pathway?
It acts as a second messenger that helps relay and amplify the signal within the cell.
Based on figure 1, which of the following statements best describes the epinephrine signaling pathway?
It involves enzymes activating other enzymes.
Gregor Mendel's pioneering genetic experiments with pea plants occurred before the discovery of the structure and function of chromosomes. Which of the following observations about inheritance in pea plants could be explained only after the discovery that genes may be linked on a chromosome?
Most offspring of a given cross have a combination of traits that is identical to that of either one parent or the other.
Which of the following statements best explains why there are fewer colonies on plate IV than on plate III?
Not all E. coli cells are successfully transformed.
DNA replication occurs
during the S phase of the cell cycle
The banding patterns of the DNA fragments reveal that
the mother cannot be the biological parent of all three children
Probability that the genotype ccdd will be produced by the parents CcDd x CcDd
1/16
Probability that the genotype Aa will be produced by the parents Aa x Aa
1/2
Probability that the genotype Rr will be produced by the parents Rr x rr
1/2
Probability that the genotype TTSs will be produced by the parents TTSs x TtSS
1/4
If three children are born to Matthew and Jane, what are the chances that the first two children will not express the trait but that the third child will be an achondroplastic dwarf?
1/8
In sheep, eye color is controlled by a single gene with two alleles. When a homozygous brown-eyed sheep is crossed with a homozygous green-eyed sheep, blue-eyed offspring are produced. If the blue-eyed sheep are mated with each other, what percent of their offspring will most likely have brown eyes?
25%
The mRNA transcribed from the DNA would read
5' AUC AAG UUU GGC GCA UUG UAA 3'
One of the affected males from the third generation has a child with a female who is a carrier. For the pedigree shown above, which of the following best expresses the probability that the couple's first son will be affected with the disorder?
50%
The probability that Matthew and Jane's first child will be an achondroplastic dwarf is
50%
Which of the following diagrams best represents hormone-activated gene expression?
A
Which of the following is the most plausible explanation for these findings? Pic of embryo
A cell surface protein on cell 4 signals cell 3 to induce formation of the worm's intestine.
Cancer can result from a variety of different mutational events. Which of the following is LEAST likely to result in the initiation of a cancerous tumor?
A defect in a cell-cycle checkpoint prevents a cell from entering the S phase
Damaged tissue releases chemicals that activate platelets and stimulate the formation of blood clots. Which of the following predictions about the activity of platelets best describes a positive feedback mechanism?
Activated platelets release chemicals that activate more platelets.
The vertebrate forelimb initially develops in the embryo as a solid mass of tissue. As development progresses, the solid mass near the end of the forelimb is remodeled into individual digits. Which of the following best explains the role of apoptosis in remodeling of the forelimb?
Apoptosis involves the regulated activation of proteins in specific cells of the developing forelimb that leads to the death of those cells.
Which is a scientific claim that is consistent with the information provided and Figure 1 ?
When bound to the operator, the repressor protein prevents lactose metabolism in E. coli.
Which of the following is probably the genotype of the dark, short-haired parent in cross I?
CCBB
In cross II, the genotype of the dark, short-haired parent is
CcBb
In which of the following would there NOT be a change in the amino acid sequence of the peptide coded for by this DNA?
Changing 3' AAA 5' to read 3' AAG 5'
Which of the following presents a correct interpretation of the changes in chromosome number depicted in figure 1?
Chromosomes enter metaphase containing two chromatids attached by a centromere. During anaphase, the chromatids are separated, each becoming a chromosome. Cytokinesis distributes the chromosomes into two separate cells.
Enzyme used during replication to attach Okazaki fragments to each other
DNA ligase
Enzyme used to position nucleotides during DNA replication
DNA polymerase
Which of the following is most likely to create genetic variation in a population?
DNA polymerase errors during replication
Which of the following correctly explains where DNADNA replication will begin on the strand oriented 5'→3'5′→3′, reading from left to right?
DNA replication will be initiated immediately to the left of the RNA, since DNA polymerase requires an RNA primer.
Which of the following best describes the role of mitosis in the cell cycle?
Distributing replicated chromosomes to daughter nuclei.
Which of the following is shown by the data?
In mutant 3 cells, more time is spent in prophase/prometaphase than in the later stages of mitosis.
The Trp operon is a coordinately regulated group of genes (trpA-trpE) that are required for tryptophan biosynthesis in E. coli. Based on the figure above, which of the following correctly describes the regulation of the Trp operon?
In the presence of tryptophan, the repressor is active and binds to the Trp operator, preventing RNA polymerase from transcribing the operon.
Which of the following best explains how the development of phenotypic female Australian dragon lizards with a ZZ genotype occurs when incubation temperatures are above 32°C32°C?
Incubation temperatures above 32°C inhibit the genes on the ZZ chromosome that produce proteins necessary for male development.
Which of the following correctly explains the process shown in Figure 1 ?
Initiation of transcription is occurring because a strand of RNA is being produced from a DNA template strand.
Which of the following correctly describes the relationship of the dark-coat-color allele to the albino condition?
It is dominant.
The genotypes of Matthew and Jane are best represented as
Matt: aa Jane: Aa
Both mitosis and meiosis begin with a parent cell that is diploid. Which of the following best describes how mitosis and meiosis result in daughter cells with different numbers of chromosomes?
Mitosis produces two identical diploid daughter cells after one round of division. Meiosis produces four haploid daughter cells after two rounds of division.
Which of the following best predicts the effect of inhibiting cyclic AMP phosphodiesterase in a muscle cell stimulated by epinephrine?
Phosphorylase kinase will remain active because protein kinase A will no longer be deactivated.
Which of the following statements best explains the structure and importance of plasmids to prokaryotes?
Plasmids are circular, double-stranded DNA molecules that provide genes that may aid in survival of the prokaryotic cell.
Enzyme used in the synthesis of mRNA
RNA polymerase
Enzyme found in retroviruses that produce DNA from an RNA template
Reverse transcriptase
Which of the following is the best explanation for the fragment pattern for individual X ?
She is the mother's child from another marriage.
Most cells that have become transformed into cancer cells have which of the following characteristics when compared to normal, healthy cells?
Shorter cell cycle
Cell communication is critical for the function of both unicellular and multicellular eukaryotes. Which of the following is likely true of cell signaling?
Similar cell signaling pathways in diverse eukaryotes are evidence of conversed evolutionary processes.
Which of the following statements best explains the data set?
Since the %A and the %T are approximately the same in each sample, adenine and thymine molecules must pair up in a double-stranded DNA molecule.
Which of the following conditions will most likely cause a normal body cell to become a cancer cell?
The environment contains mutagens that induce mutations that affect cell-cycle regulator proteins.
The data above represent the results of three different crosses involving the inheritance of a gene that determines whether a certain organism is blue or white. Which of the following best explains the mechanism of inheritance of the gene?
The allele for blue is an X-linked dominant allele because there are no blue male offspring in cross 2.
Which of the following best describes how the amount of DNA in the cell changes during M phase?
The amount of DNA is halved as the cell divides into two daughter cells.
Based on the model of eukaryotic cell cycle regulation shown in the figure, which of the following best describes the effect of a drug that blocks the production of the mitotic cyclin?
The cell would be prevented from entering mitosis, and the cell would stop dividing.
Which of the following statements best explains how the genes for antibiotic resistance can be transmitted between bacteria without the exchange of bacterial chromosomal DNA?
The genes for antibiotic resistance are located on a plasmid that can be passed to neighboring bacteria.
Which of the following statements best describes how a growth factor stimulates cell division from outside a cell?
The growth factor binds to receptors on the cell surface, initiating a signal transduction pathway that activates specific target genes.
Which of the following best explains why there is no growth on plate II?
The initial E. coli culture was not ampicillin-resistant.
Which of the following outcomes will most likely result from the irreversible binding of GDP to the G protein?
The intracellular concentration of glycogen will increase.
The researchers calculate a chi-square value of 4.6 and choose a significance level of p=0.05p=0.05. Which of the following statements best completes the chi-square goodness-of-fit test?
The null hypothesis cannot be rejected because the chi-square value is less than the critical value.
The following the DNA sequence is a small part of the coding (nontemplate) strand from the open reading frame of β-hemoglobin gene. Given the codon chart listed below, what would be the effect of a mutation that deletes the G at the beginning of the DNA sequence?
The reading frame of the sequence would shift, causing a change in the amino acid sequence after that point.
Which of the following is the most likely explanation of the results?
The two genes are linked on an autosome.
Researchers studying cell cycle regulation in budding yeast have observed that a mutation in the CDC15 gene causes cell cycle arrest in telophase when the yeast cells are incubated at an elevated temperature. Which of the following statements best predicts the effect of the cell cycle arrest on proliferating yeast cells?
The yeast cells will replicate their chromosomes but will fail to complete cytokinesis.
A genetic counselor is consulted by a young man who is worried about developing Huntington's disease, an inherited disorder caused by a dominant allele of a single gene. The young man explains that his cousin was recently diagnosed with Huntington's disease, and the news has caused him to consider his own risk of developing the disorder. Which of the following questions will best help the genetic counselor to evaluate the risk of the young man developing Huntington's disease and transmitting it to his children?
Were your parents or grandparents ever diagnosed with Huntington's disease?
Plates I and III were included in the experimental design in order to
demonstrate that the E. coli cultures were viable
