Question 1

Transposons can be deleterious to a host genome because they can

Accepted Answer

A)   translate a coding sequence into protein.
B)   act as regulatory elements.
C)   prevent beneficial mutations.
D)   cause recombination errors. D

Question 2

When comparing recombination rates between a dog, with a genome size of 2,410 Mb, and a mustard weed, with a genome size of 100 Mb, which would you expect to have a larger recombination rate per kilobase? Explain your answer.

Accepted Answer

Recombination rate per kb is negatively correlated with genome size. Thus, one would expect the mustard weed to have a larger per-kilobase recombination rate than the dog, because its genome is smaller.

Question 3

Which of the following statements is FALSE regarding viral genomes?

Accepted Answer

A)   Viral genomes tend to be extremely compact and compressed.
B)   DNA-based viruses have genomes comparable in size to most prokaryotes.
C)   Because viruses replicate many times within a host cell, their capsules must be very small, which constrains the amount of genetic material that can be contained inside.
D)   Most viruses undergo strong natural selection for rapid replication. B

Question 4

GC content refers to the

Accepted Answer

A)   G-value paradox.
B)   C-value paradox.
C)   fraction of G and C nucleotides in the genome.
D)   number of genes on a chromosome.

Question 5

What are transcription factors and how do they address the G-value paradox?

Accepted Answer

The answer of What are transcription factors and how do...

Question 6

Certain single-celled amoeba have a genome that is 1,000 times the size of the genome of a complex multicellular puffer fish. This is an example of what phenomenon?

Accepted Answer

A)   the C-value paradox
B)   the G-value paradox
C)   GC skew
D)   codon usage bias

Question 7

What general patterns of recombination have been observed in eukaryotic genomes?

Accepted Answer

The answer of What general patterns of recombination have been...

Question 8

What was the first eukaryotic organism to have its entire genome sequenced?

Accepted Answer

A)   the bacteriophage MS2
B)   the bacterium Haemophilus influenzae
C)   the yeast Saccharomyces cerevisiae
D)   the nematode Caenorhabditis elegans

Question 9

Describe the characteristics of a haplotype block.

Accepted Answer

The answer of Describe the characteristics of a haplotype block....

Question 10

Most prokaryotic genomes are structured as ________ chromosome(s).

Accepted Answer

A)   one single circular
B)   many circular
C)   one single linear
D)   many linear

Question 11

Which of the following makes up the smallest fraction of the human genome?

Accepted Answer

A)   protein-coding genes
B)   LINE elements
C)   SINE elements
D)   introns

Question 12

Viral genomes exhibit extreme compression in size, and this is possible because multiple genes may be packed in the same region of the genome. Which of the following is NOT a way in which this can occur?

Accepted Answer

A)   Multiple genes can be packed in the same reading frame but only partially overlapping.
B)   Multiple genes can be located in the same region but with different reading frames.
C)   Proteins can be produced by reading in the same reading frame but with genes starting in different places using different start codons.
D)   Certain genes are located on multiple chromosomes.

Question 13

What is the source of DNA acquired by a bacterial cell during conjugation?

Accepted Answer

A)   the environment
B)   bacteriophage and other viral pathogens
C)   other bacteria
D)   the eukaryotic host cell

Question 14

Why are transposons considered selfish genetic elements?

Accepted Answer

The answer of Why are transposons considered selfish genetic elements?...

Question 15

Which of the following tends to contribute to an overall increase in genome size over evolutionary time?

Accepted Answer

A)   small genetic elements capable of self-catalyzing their movement
B)   selection on cell size
C)   selection on replication speed
D)   the cell's energetic efficiency as it relates to cell volume

Question 16

A researcher collects a soil sample and sequences the entire genomes of two prokaryotes found in the sample. In these genomes, he finds identical prophage DNA located in different areas of the two genomes. Based on the similarity of the sequences of the prophages and their placement in the prokaryotes' genomes, what could he conclude about the relatedness of the two prokaryotes?

Accepted Answer

The answer of A researcher collects a soil sample and...

Question 17

The exon theory of genes states that

Accepted Answer

A)   genomes consist solely of exons.
B)   introns are deleterious and are purged from the genome.
C)   introns lead to recombination errors.
D)   many current genes arose through the rearrangement of exons into new combinations.

Question 18

A researcher discovers a new prokaryote whose genome is ~8 Mb in size. Based on the figure shown, what type of organism is this likely to be?

Accepted Answer

A)   free-living bacterium
B)   obligate parasitic bacterium
C)   obligate symbiontic bacterium
D)   Archaean

Question 19

For which of the following would a syntenic dot plot NOT be useful?

Accepted Answer

A)   when comparing gene orders among prokaryotes
B)   when identifying chromosomal inversions
C)   when examining genomic evolution in bacteria
D)   when only fragments of DNA are available for sequencing

Question 20

When examining recombination rates across a chromosome, a researcher detects an area of high recombination rates. What could he or she infer based on this observation?

Accepted Answer

A)   This region is likely the centromere.
B)   This region is likely a telomere.
C)   This region is likely a recombination hotspot.
D)   This region is within a protein-coding gene.

Exam 10: Genome Evolution