Question 1

Which of the following best explains why humans and chimpanzees have approximately 98% DNA similarity, yet display significant differences in physical and behavioral traits?

Accepted Answer

Differences in regulatory sequences and gene expression patterns contribute to the variation.

Question 2

The Human Genome Project (HGP) revealed that only about 1.5% of the human genome codes for proteins. Which of the following best describes the function of the remaining noncoding DNA?

Accepted Answer

It includes regulatory sequences, introns, and various types of repetitive DNA, some of which play roles in gene regulation.

Question 3

A mutation occurs in a gene, but the amino acid sequence of the resulting protein does not change. What type of mutation is this?

Accepted Answer

Silent mutation

Question 4

Which equation best represents the mutation rate per site per generation in roundworms, given 26 mutations found in 771,672 base pairs over 214 generations?

Accepted Answer

$\frac{26}{771672 	imes 214}$

Question 5

Which of the following is NOT a mechanism by which genetic variation is generated?

Accepted Answer

Horizontal gene transfer in humans

Question 6

Frame shift mutations are most likely caused by which of the following genetic events?

Accepted Answer

Insertion or deletion of nucleotides not in multiples of three

Question 7

Which of the following best describes the process of exon shuffling?

Accepted Answer

Exons from different genes are combined during meiotic errors, potentially creating new genes with novel functions.

Question 8

Which of the following statements about polyploidy is correct?

Accepted Answer

Polyploidy results in organisms with more than two sets of chromosomes and is a major mechanism of speciation in plants.

Question 9

Which of the following best explains why fetal hemoglobin has a higher affinity for oxygen than adult hemoglobin?

Accepted Answer

Fetal hemoglobin is coded by different globin genes that allow for enhanced oxygen transfer from mother to offspring.

Question 10

Which of the following is a plausible outcome of unequal crossing over during meiosis?

Accepted Answer

Creation of multigene families through gene duplication

Question 11

Which of the following best describes the function of homeotic (Hox) genes?

Accepted Answer

They regulate the spatial arrangement of body segments during development.

Question 12

Which of the following equations represents the number of possible combinations of chromosomes due to independent assortment in a diploid organism with $n$ chromosome pairs?

Accepted Answer

$2^n$

Question 13

A chromosome inversion occurs when:

Accepted Answer

A section of chromosome is broken at both ends, detaches, and flips, altering the order of genes.

Question 14

Which of the following is a consequence of gene duplication followed by mutation?

Accepted Answer

Formation of multigene families with similar but not identical functions

Question 15

Which of the following best describes the colinearity of Hox genes in vertebrates?

Accepted Answer

The order of Hox genes in DNA matches their order of expression along the anterior-posterior body axis.

Question 16

Which of the following is a plausible effect of a mutation in the regulatory sequence of a gene?

Accepted Answer

The gene may be expressed at the wrong time or in the wrong tissue, potentially causing developmental abnormalities.

Question 17

Which of the following is true about pseudogenes?

Accepted Answer

They are former genes that have accumulated mutations and are nonfunctional.

Question 18

Which of the following best describes the role of transposons in genome evolution?

Accepted Answer

Transposons can move within the genome, causing mutations and contributing to genetic variation.

Question 19

Which of the following is a likely outcome of two duplications of Hox genes in the vertebrate lineage?

Accepted Answer

Evolution of new vertebrate characteristics due to increased complexity in developmental regulation.

Ch 21

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