Question 1

Which of the following best explains why the human genome contains only about 20,000 protein-coding genes, yet human cells can produce over 100,000 different polypeptides?

Accepted Answer

Alternative splicing and post-translational modifications allow a single gene to produce multiple polypeptides.

Question 2

A researcher is using the BLAST tool to compare a newly sequenced gene from a bacterium to known sequences in GenBank. What is the primary purpose of this analysis?

Accepted Answer

To identify sequence similarities that may reveal evolutionary relationships or gene function.

Question 3

Which of the following statements about transposable elements is CORRECT?

Accepted Answer

Retrotransposons move via an RNA intermediate and leave a copy at the original site, increasing genome size.

Question 4

A plant species is found to have undergone polyploidy, resulting in extra sets of chromosomes. Which of the following is a likely evolutionary consequence of this event?

Accepted Answer

Duplicated genes may accumulate mutations and evolve new functions, potentially leading to speciation.

Question 5

Which of the following best describes the role of the ENCODE project in genomics?

Accepted Answer

It systematically identified functional elements, including noncoding RNAs and regulatory sequences, in the human genome.

Question 6

A geneticist compares the genomes of humans and chimpanzees and finds that they differ by about 1.2% in single nucleotide substitutions, but by an additional 3% when insertions, deletions, and duplications are included. What does this suggest about the evolutionary divergence between these species?

Accepted Answer

Structural variations such as insertions, deletions, and duplications contribute significantly to genomic divergence.

Question 7

Which of the following mechanisms is most likely to result in the formation of a multigene family?

Accepted Answer

Gene duplication followed by divergence of gene copies.

Question 8

A patient’s cancer cells are sequenced, and a unique mutation is identified that is not present in their normal cells. How can this information be used in personalized medicine?

Accepted Answer

By designing a targeted therapy that specifically inhibits the mutated protein in the cancer cells.

Question 9

Which of the following statements about homeobox-containing genes is TRUE?

Accepted Answer

They encode transcription factors that regulate developmental processes and are highly conserved across animals.

Question 10

Which of the following best explains why prokaryotic genomes are generally smaller and more gene-dense than eukaryotic genomes?

Accepted Answer

Prokaryotic genomes contain little noncoding DNA and lack introns, resulting in higher gene density.

Question 11

A scientist discovers a DNA sequence in humans that is nearly identical in rats and mice, but does not code for a protein. What is the most likely explanation for the conservation of this sequence?

Accepted Answer

It is a highly conserved noncoding region likely to have an important regulatory or structural function.

Question 12

Which of the following is a direct consequence of unequal crossing over during meiosis?

Accepted Answer

Duplication of gene regions on one chromatid and deletion on the other.

Question 13

Which of the following best describes the function of the FOXP2 gene in humans?

Accepted Answer

It is crucial for the development of speech and language, with mutations causing severe speech impairment.

Question 14

Which of the following statements about the whole-genome shotgun sequencing approach is CORRECT?

Accepted Answer

It involves randomly breaking the genome into fragments, sequencing them, and assembling the sequences using overlapping regions.

Question 15

Short tandem repeats (STRs) are widely used in forensic genetics. Which property of STRs makes them especially useful for genetic profiling?

Accepted Answer

The number of repeat units varies greatly among individuals, providing a unique genetic fingerprint.

Question 16

Which of the following is a likely outcome if a transposable element inserts into the regulatory region of a gene?

Accepted Answer

The gene’s expression may be altered, potentially increasing or decreasing protein production.

Question 17

Which of the following best illustrates the concept of exon shuffling in genome evolution?

Accepted Answer

A gene acquires a new exon from another gene, resulting in a protein with a novel combination of functional domains.

Question 18

Which of the following statements about comparative genomics is TRUE?

Accepted Answer

It can reveal evolutionary relationships by comparing gene sequences across species.

Question 19

A chromosomal inversion is found to increase reproductive success in a population of Icelandic females. According to evolutionary theory, what is the most likely outcome for the frequency of this inversion over generations?

Accepted Answer

The inversion will increase in frequency due to natural selection.

Genomics and Genome Evolution: Structure, Function, and Comparative Analysis

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