AP Biology Mid-Term Exam

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, nucleus disintegration, and new cell generation.
C. signal reception, signal transduction, and cellular response.
D. the alpha, beta, and gamma stages. e. signal reception, cellular response, and cell division.

Which description below is not a way that transposable elements can contribute to genome evolution?

A. by integrating into genes and disrupting their function
B. All the choices describe how transposable elements can contribute to genome evolution.
C. by moving exons from one gene to another, creating proteins with novel combinations of exons
D. by introducing homologous sequences into various locations within the genome, allowing unequal crossing over to occur during meiosis
E. by moving genes to new chromosomal locations

Which of the following is least related to the other items?

A. wobble
B. triplet code
C. anticodon
D. snRNP
E. tRNA

In the late 1950s, Meselson and Stahl grew bacteria in a medium containing "heavy" nitrogen (15N) and then transferred them to a medium containing 14N. Which of the results in the figure above would be expected after one DNA replication in the presence of 14N?

A. A
B. C
C. D
D. B
E. E

A eukaryotic cell lacking telomerase would

A. be highly sensitive to sunlight.
B. be unable to repair thymine dimers.
C. undergo a reduction in chromosome length.
D. produce Okazaki fragments.
E. have a high probability of becoming cancerous.

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. Amino acids (and thus proteins) also have nitrogen atoms; thus, the radioactivity would not distinguish between DNA and proteins.
B. Radioactive nitrogen has a half-life of 100,000 years, and the material would be too dangerous for too long.
C. There is no radioactive isotope of nitrogen.
D. Meselson and Stahl already did this experiment.
E. Although there are more nitrogens in a nucleotide, labeled phosphates actually have 16 extra neutrons; therefore, they are more radioactive.

The genetic code is essentially the same for all organisms. From this, one can logically assume all of the following except

A. different organisms have the same number of different types of amino acids.
B. the same codons in different organisms usually translate into the same amino acids.
C. a gene from an organism could theoretically be expressed by any other organism.
D. all organisms have a common ancestor.
E. DNA was the first genetic material.

Refer to the choices to answer the following question.

A. photosynthesis
B. respiration
C. both photosynthesis and respiration
D. neither photosynthesis nor respiration

reduction of oxygen which forms water

a. A
b. B
c. C
d. D

Refer to the choices to answer the following question.

A. photosynthesis
B. respiration
C. both photosynthesis and respiration
D. neither photosynthesis nor respiration

synthesis of ATP by the chemiosmotic mechanism

a. A
b. B
c. C
d. D

Use the following answers for the following question.

A. transformation
B. transduction
C. conjugation
D. transposition
E. translation

External DNA is assimilated by a cell.

a. A
b. B
c. C
d. D
e. E

Use the following answers for the following question.

A. transduction
B. transformation
C. transposition
D. conjugation
E. translation

A plasmid is exchanged between bacteria through a pilus.

a. A
b. B
c. C
d. D
e. E

Use the following answers for the following question.

A. transduction
B. conjugation
C. transposition
D. transformation
E. translation

DNA is transferred from one bacterium to another by a virus.

a. A
b. B
c. C
d. D
e. E

Use the terms below to answer the following question.

A. transposons
B. multigene family
C. pseudogenes
D. methylated DNA
E. simple sequence DNA

-globins and B-globins are classic examples of which type of DNA?

a. A
b. B
c. C
d. D
e. E

Use the terms below to answer the following question.

A. multigene family
B. methylated DNA
C. transposons
D. simple sequence DNA
E. pseudogenes

This is most commonly found in inactivated DNA regions.

a. A
b. B
c. C
d. D
e. E

According to the fluid mosaic model of cell membranes, which of the following is a true statement about membrane phospholipids?

A. They occur in an uninterrupted bilayer, with membrane proteins restricted to the surface of the membrane.
B. They frequently flip-flop from one side of the membrane to the other.
C. They have hydrophilic tails in the interior of the membrane.
D. They are free to depart from the membrane and dissolve in the surrounding solution.
E. They can move laterally along the plane of the membrane.

Which of the following is true for both prokaryotic and eukaryotic gene expression?

A. RNA polymerase binds to the promoter region to begin transcription.
B. After transcription, a 3' poly-A tail and a 5' cap are added to mRNA.
C. mRNA is synthesized in the 3' ? 5' direction.
D. Translation of mRNA can begin before transcription is complete.
E. The mRNA transcript is the exact complement of the gene from which it was copied.

It became apparent to Watson and Crick after completion of their model that the DNA molecule could carry a vast amount of hereditary information in its

A. side groups of nitrogenous bases.
B. sequence of bases.
C. different five-carbon sugars.
D. complementary pairing of bases.
E. phosphate-sugar backbones.

What is the function of reverse transcriptase in retroviruses?

A. It converts host cell RNA into viral DNA.
B. It hydrolyzes the host cell's DNA.
C. It uses viral RNA as a template for DNA synthesis.
D. It translates viral RNA into proteins.
E. It uses viral RNA as a template for making complementary RNA strands.

A part of an mRNA molecule with the following sequence is being read by a ribosome: 5' CCG-ACG 3' (mRNA). The following activated transfer RNA molecules (with their anticodons shown in the 3' to 5' direction) are available. Two of them can correctly match the mRNA so that a dipeptide can form.

The dipeptide that will form will be

A. glycine-cysteine.
B. threonine-glycine.
C. alanine-alanine.
D. cysteine-alanine.
E. proline-threonine.

Which term most precisely describes the cellular process of breaking down large molecules into smaller ones?

A. catalysis
B. anabolism
C. catabolism
D. metabolism
E. dehydration

Which of the following best describes the complete sequence of steps occurring during every cycle of PCR?

1. The primers hybridize to the target DNA.
2. The mixture is heated to a high temperature to denature the double stranded target DNA.
3. Fresh DNA polymerase is added.
4. DNA polymerase extends the primers to make a copy of the target DNA.

A. 1, 3, 2, 4
B. 3, 4, 1, 2
C. 2, 1, 4
D. 3, 4, 2
E. 2, 3, 4

After mixing a heat-killed, phosphorescent strain of bacteria with a living non-phosphorescent strain, you discover that some of the living cells are now phosphorescent. The best evidence that the ability to fluoresce is a heritable trait would be an observation that

A. DNA passed from the heat-killed strain to the living strain.
B. protein passed from the heat-killed strain to the living strain.
C. the phosphorescence in the living strain is especially bright.
D. descendants of the living cells are also phosphorescent.
E. both DNA and protein passed from the heat-killed strain to the living strain.

____ is used to make complementary DNA (cDNA) from RNA

A. DNA ligase
B. gene cloning
C. gel electrophoresis
D. reverse transcriptase
E. restriction enzymes

____ separates molecules by movement due to size and electrical charge

A. gel electrophoresis
B. restriction enzymes
C. reverse transcriptase
D. gene cloning
E. DNA ligase

____ produces multiple identical copies of a gene for basic research or for large-scale production of a gene product

A. restriction enzymes
B. reverse transcriptase
C. DNA ligase
D. gene cloning
E. gel electrophoresis

____ cuts DNA molecules at specific locations

A. restriction enzymes
B. DNA ligase
C. gel electrophoresis
D. gene cloning
E. reverse transcriptase

____ seals the sticky ends of restriction fragments to make recombinant DNA

A. restriction enzymes
B. DNA ligase
C. reverse transcriptase
D. gel electrophoresis
E. gene cloning

What is the enzymatic function of restriction enzymes?

A. to add new nucleotides to the growing strand of DNA
B. to join nucleotides during transcription
C. to join nucleotides during replication
D. to repair breaks in sugar-phosphate backbones
E. to cleave nucleic acids at specific sites

Which of the following statements is false when comparing prokaryotes with eukaryotes?

A. Prokaryotes produce Okazaki fragments during DNA replication, but eukaryotes do not.
B. The rate of elongation during DNA replication is higher in prokaryotes than in eukaryotes.
C. Prokaryotic chromosomes have a single origin of replication, whereas eukaryotic chromosomes have many.
D. The prokaryotic chromosome is circular, whereas eukaryotic chromosomes are linear.
E. Eukaryotes have telomeres, and prokaryotes do not.

Where does glycolysis takes place?

A. mitochondrial inner membrane
B. mitochondrial outer membrane
C. mitochondrial matrix
D. cytosol
E. mitochondrial intermembrane space

RNA polymerase and DNA polymerase differ in that

A. RNA polymerase binds to single-stranded DNA, and DNA polymerase binds to double-stranded DNA.
B. RNA polymerase can initiate RNA synthesis, but DNA polymerase requires a primer to initiate DNA synthesis.
C. RNA polymerase uses RNA as a template, and DNA polymerase uses a DNA template.
D. RNA polymerase does not need to separate the two strands of DNA in order to synthesize an RNA copy, whereas DNA polymerase must unwind the double helix before it can replicate the DNA.
E. RNA polymerase is much more accurate than DNA polymerase.

The process of transduction usually begins

A. when the hormone is released from the gland into the blood.
B. after the target cell divides.
C. when the chemical signal is released from the alpha cell.
D. when the signal molecule changes the receptor protein in some way.
E. after the third stage of cell signaling is completed.

If a cell were unable to produce histone proteins, which of the following would be expected to occur?

A. Pseudogenes would be transcribed to compensate for the decreased protein in the cell.
B. Amplification of other genes would compensate for the lack of histones.
C. There would be an increase in the amount of "satellite" DNA produced during centrifugation.
D. Spindle fibers would not form during prophase.
E. The cell's DNA couldn't be packed into its nucleus.

Viruses are referred to as obligate parasites because

A. they can incorporate nucleic acids from other viruses.
B. viral DNA always inserts itself into host DNA.
C. they must use enzymes encoded by the virus itself.
D. they invariably kill any cell they infect.
E. they cannot reproduce outside of a host cell.

All of the following molecules are part of the cell membrane except

A. lipids.
B. nucleic acids.
C. proteins.
D. steroids.
E. phosphate groups.

Which of the following is characteristic of the lytic cycle?

A. Viral DNA is incorporated into the host genome.
B. The virus-host relationship usually lasts for generations.
C. The viral genome replicates without destroying the host.
D. Many bacterial cells containing viral DNA are produced.
E. A large number of phages are released at a time.

Which of the following represents a similarity between RNA and DNA?

A. Both are double-stranded.
B. the presence of uracil
C. the presence of an OH group on the 2' carbon of the sugar
D. nucleotides consisting of a phosphate, sugar, and nitrogenous base
E. Both are found exclusively in the nucleus

What is the most logical sequence of steps for splicing foreign DNA into a plasmid and inserting the plasmid into a bacterium?
I. Transform bacteria with recombinant DNA molecule.
II. Cut the plasmid DNA using restriction enzymes.
III. Extract plasmid DNA from bacterial cells.
IV. Hydrogen-bond the plasmid DNA to nonplasmid DNA fragments.
V. Use ligase to seal plasmid DNA to nonplasmid DNA.

A. IV, V, I, II, III
B. III, II, IV, V, I
C. I, II, IV, III, V
D. II, III, V, IV, I
E. III, IV, V, I, II

Which of the following statements is true?

A. Heterochromatin is composed of DNA, whereas euchromatin is made of DNA and RNA.
B. Both heterochromatin and euchromatin are found in the cytoplasm.
C. Heterochromatin is highly condensed, whereas euchromatin is less compact.
D. Euchromatin is not transcribed, whereas heterochromatin is transcribed.
E. Only euchromatin is visible under the light microscope.

Muscle cells and nerve cells in one species of animal owe their differences in structure to

A. having unique ribosomes.
B. having different chromosomes.
C. having different genes.
D. differential gene expression.
E. using different genetic codes.