ap bio unit 6 multiple choice questions
Which of the following graphs best predicts the data collected during the experiment?
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When DNA replicates, each strand of the original DNA molecule is used as a template for the synthesis of a second, complementary strand. Which of the following figures most accurately illustrates enzyme-mediated synthesis of new DNA at a replication fork?
3' solid going toward 5' dashed moving away
Which of the following best explains a process occurring between point 1 and point 2 in Figure 3 ?
A poly‑A tail is added to RNARNA.
Which of the following does NOT occur during translation?
DNA information is copied into mRNA to make a polypeptide.
Which of the following correctly explains where DNA replication will begin on the strand oriented 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 helps explain how the process represented in Figure 1 produces DNA molecules that are hybrids of the original and the newly synthesized strands?
Each newly synthesized strand remains associated with its template strand to form two copies of the original DNA molecule.
Which of the following statements best explains the role of Enzyme 1 in the DNA replication process?
Enzyme 1 is a topoisomerase that relieves tension in the overwound DNA in front of a replication fork.
Which description of DNA replication is correct?
Helicases separate the two strands of the double helix, and DNA polymerases then construct two new strands using each of the original strands as templates.
Nucleotide base pairing in DNA is universal across organisms. Each pair (T−A; C−G) consists of a purine and a pyrimidine. Which of the following best explains how the base pairs form?
Hydrogen bonds join a double-ringed structure to a single-ringed structure in each pair.
Which of the following best explains how this model illustrates DNA replication of both strands as a replication fork moves?
I is synthesized continuously in the 5′ to 3′ direction, and III is synthesized in segments in the 5′ to 3′ direction.
A model that represents a process occurring in a cell of a particular organism is shown in Figure 1. Figure 1. Process occurring in a cell 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 best explains what process is represented in Figure 1 ?
New DNA strands are being synthesized in the 5' to 3' direction from their DNA templates.
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.
Which of the following best explains how the pattern of DNA arrangement in chromosomes could be used, in most cases, to determine if an organism was a prokaryote or a eukaryote?
Prokaryotic DNA - Single circular chromosome Eukaryotic DNA - Multiple linear chromosomes
Which of the following statements provides the best explanation of the processes illustrated in Figure 1?
Sections of the pre- rRNA are removed, and the mature rRNA molecules are available to combine with proteins to form the ribosomal subunits.
A woman develops Huntington's disease. Her father had the disorder. Her mother did not, and there is no history of the disorder in the mother's family. Which of the following best explains how the woman inherited Huntington's disease?
She inherited an allele with more than 40 CAG repeats in the HTT gene from her father.
Erwin Chargaff investigated the nucleotide composition of DNA. He analyzed DNA from various organisms and measured the relative amounts of adenine (A), guanine (G), cytosine (C), and thymine (T) present in the DNA of each organism. Table 1 contains a selected data set of his results. Table 1. Nucleotide composition of sample DNA from selected organisms Organism Relative Amounts of Bases %A %G %C %T %(G+C) %(A+T) Octopus 33.2 17.6 17.6 31.6 35.2 64.8 Chicken 28.0 22.0 21.6 28.4 43.7 56.4 Rat 28.6 21.4 20.5 28.4 42.9 56.0 Grasshopper 29.3 20.5 20.7 29.3 41.2 58.6 Wheat 27.3 22.7 22.8 27.1 45.5 54.4 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.
Given the results shown in Figure 1, which of the following correctly describes a relationship between the two species?
Species B has more short fragments of DNA than species A does.
Antibiotics interfere with prokaryotic cell functions. Streptomycin is an antibiotic that affects the small ribosomal subunit in prokaryotes. Specifically, streptomycin interferes with the proper binding of tRNA to mRNA in prokaryotic ribosomes. Which of the following best predicts the most direct effect of exposing prokaryotic cells to streptomycin?
Synthesis of polypeptides will be inhibited.
Which of the following best explains what strand X represents?
The antisense strand, because it is serving as a template
A cell needs to metabolize the substrate illustrated in Figure 1 for a vital cellular function. Which of the following best explains the long-term effect on the cell of splicing that yields only enzyme C mRNA?
The cell will die because it is unable to metabolize the substrate without enzyme A , which is structurally specific for the substrate shown.
Figure 1 represents part of a process that occurs in eukaryotic cells. There are untranslated regions (UTR) in this sequence. Which of the following best explains the process represented by Figure 1 ?
The enzyme-regulated processing of pre‑mRNA into mature mRNA
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 best predicts the phenotype of an individual who is homozygous for this TYR mutation?
The mutation will change all subsequent amino acids in the TYR protein, leading to nonfunctional TYR protein. Individuals with this mutation will lack melanin in their hair, skin, and eyes and will not tan in response to UVUV radiation.
The features of this model provide evidence for which explanation of why all growing strands are synthesized in a 5′ to 3′ direction?
The phosphate group, attached to the 5′ carbon of the dTMP, forms a covalent bond with the oxygen atom attached to the 3′ carbon of the growing strand.
Which of the following best predicts what will happen when a normal cell is exposed to a retrovirus?
The reverse transcriptase will produce DNA from the viral RNA, which can be incorporated into the host's genome and then transcribed and translated.
Which of the following best describes the arrangement of genetic information in a DNA molecule?
The three-nucleotide words of a gene are arranged in a non-overlapping series on the DNA template strand.
Which of the following would be the leading strand, why?
The top strand, because DNA polymerase replicates the template strand in a continuous 5' à 3' direction.
Which of the following best supports the claim that binding of miRNA‑delta to the miRNA binding site inhibits translation of gene Q mRNA?
When the miRNA binding site sequence is altered, translation of Q mRNA occurs in the presence of miRNA-delta.
What technique was most helpful to Watson and Crick in developing their model for the structure of DNA?
X-ray crystallography
Analysis of DNA sequences from two individuals of the same species results in a greater estimate of genetic variability than does analysis of amino acid sequences from the same individuals because
different DNA sequences can code for the same amino acid
During the infection cycle for a typical retrovirus, such as HIV, which uses RNA as genetic material, the genetic variation in the resulting population of new virus particles is very high because of
errors introduced in the DNA molecule through reverse transcription
Which of the following attributes of DNA is most crucial to its accurate duplication?
its specific complementary base pairing and hydrogen bonding
The information in DNA is contained in __________.
the sequence of nucleotides along the length of one strand of the DNA molecule