Question 1

Which field or approach is most likely to lead directly to a reduction in the negative side effects associated with a drug used to treat diabetes?

Accepted Answer

Pharmacogenomics is the study of how an individual's genetic makeup influences their response to drugs. By identifying genetic variations in individuals that affect drug metabolism or efficacy, personalized treatment plans can be created to reduce negative side effects associated with the drug.

Question 2

The Alu element, which accounts for over 10 percent of the human genome, uses an RNA intermediate and employs a "copy and paste" mechanism of replication.It is not translated.It is thus an example of a

Accepted Answer

The presence of an RNA intermediate and "copy and paste" mechanism of replication are characteristic features of SINEs, of which Alu elements are a well-known example. Alu elements are not translated, meaning they do not code for proteins or function as genes. The other choices listed are not characteristic of Alu elements.

Question 3

Two graduate students are working in the same lab.Jane is investigating the mariner transposon, a DNA transposon.Sam is studying Alu, a SINE.What property is shared by Jane's and Sam's elements?

Accepted Answer

The answer of Two graduate students are working in the...

Question 4

The Denisovans are an extinct species of human that lived in Siberia several tens of thousands of years ago.We now have sequence information from these Denisovans.What evidence would best support Denisovans having had the capacity for speech?

Accepted Answer

The FOXP2 gene has been linked to the capacity for speech in humans. The fact that the Denisovan FOXP2 gene resembled the human variant suggests that they may have also had the capacity for speech. The other options do not provide direct evidence related to speech ability.

Question 5

Which statement comparing the human and Neanderthal genomes is true?

Accepted Answer

Genetic analysis has shown that humans and Neanderthals interbred and modern humans today have traces of Neanderthal DNA in their genomes.

Answer: B
 Studies have shown that the MC1R gene, which gives rise to red hair and pale skin in humans, was more active in some Neanderthals than in others. This suggests that some Neanderthals may have also had pale skin and red hair.

The other statements are not entirely true. While the Neanderthal genome is not identical to human DNA, it is actually about 99.7% similar. While the FOXP2 gene has been linked to speech in humans, the differences in the Neanderthal version of the gene do not necessarily mean they were unable to speak. And while there may be some genetic differences between humans and Neanderthals due to point mutations, this does not mean there are no unique human DNA sequences.

Question 6

Which statement about the globin genes is true?

Accepted Answer

Different tissues in mammals will express different globin genes, allowing for specialized oxygen binding in different parts of the body.

Answer: B
 The globin genes first arose in invertebrates, specifically the ancestors of modern-day polychaete worms.

Answer: E
 All forms of human globins do not bind oxygen with the same affinity. For example, fetal hemoglobin binds oxygen more tightly than adult hemoglobin.

Therefore, the correct statement about the globin genes is C: Different tissues in mammals will express different globin genes.

Question 7

In some species of moths, the genes that make the protein-rich chorion for the eggshell are found in multiple copies in order to maximize the production of chorion at specific times.In this regard, these chorion genes are most like

Accepted Answer

rRNA genes are also found in multiple copies in the genome to meet the high demand for ribosomal RNA production during protein synthesis, similar to how multiple copies of chorion genes ensure sufficient production of the protein-rich chorion.

Question 8

Genomic analysis of a fish reveals that this species has dozens of functional copies of a gene that are all nearly identical to one another.What is the most likely explanation for this finding?

Accepted Answer

The presence of multiple functional copies of a gene that are nearly identical suggests that a large amount of the gene product is needed in a relatively short time period. This could be due to a high demand for the protein that the gene encodes, or because the protein needs to be produced rapidly in response to certain stimuli.

Question 9

What is the biggest difference between the human genome and the genomes of model animal species such as Drosophila?

Accepted Answer

The answer of What is the biggest difference between the...

Question 10

A piece of DNA that is 3 kb in length is found in many locations throughout the genome.How would you decide whether this was a LINE or a DNA transposon?

Accepted Answer

LINEs (Long Interspersed Nuclear Elements) are a type of retrotransposon that replicate through an RNA intermediate. This distinguishes them from DNA transposons, which do not use an RNA intermediate but move directly as DNA.

Question 11

Which statement best supports the notion that humans and Neanderthals should be considered separate species?

Accepted Answer

Chromosomal rearrangements are significant genetic differences that usually only occur between species, making it a strong argument for humans and Neanderthals being separate species. The other options do not necessarily indicate species distinction.

Question 12

The hypothetical antianxiety drug Epitome is inactive when taken, but it is activated by the rasputin enzyme a few hours after injection.Alleles 1 and 2 of the gene that encodes rasputin encode enzymes with similar activity levels.Individuals with one or both copies of allele 3, which is very rare, have much higher levels of enzyme activity.Individuals who have both copies of allele 4 have much lower levels of enzyme activity.Heterozygotes of allele 4 have normal levels of enzyme activity.The individuals who are most likely to experience negative side effects from Epitome are those whose genotypes have one copy of allele _______ and one copy of allele _______.

Accepted Answer

Individuals with one copy of allele 2 and one copy of allele 3 would have much higher levels of enzyme activity due to the presence of allele 3, which significantly increases enzyme activity. This could lead to the drug being activated more quickly or more intensely, potentially causing negative side effects.

Question 13

The Denisovans are an extinct species of human that lived in Siberia several tens of thousands of years ago.We now have sequence information from these Denisovans.What evidence would best support Denisovans having had red hair?

Accepted Answer

The MC1R gene is known to influence hair color in humans, with certain variants leading to red hair typically through reduced activity. Therefore, a Denisovan MC1R protein variant with lower activity than the typical human variant would support the hypothesis that Denisovans could have had red hair.

Question 14

Which techniques, tools, or activities would be most directly useful in identifying the genetic variants associated with a complex human disease such as schizophrenia?

Accepted Answer

Haplotype mapping is a technique that can be used to identify regions of the genome that are associated with a disease. Since schizophrenia is a complex disease, it is likely caused by multiple genetic variants, and haplotype mapping can help identify these variants.

Answer: B
 Selective inactivation is a technique that involves selectively turning off certain genes in cells to determine their function. This technique can be useful in identifying genes that are associated with schizophrenia by turning off genes that are suspected to be involved in the disease and observing the effects on cellular function.

Answer: E
 Performing a pseudogene screen involves sequencing the genome to identify pseudogenes, which are non-functional copies of genes that have been mutated over time. Pseudogenes can be used to identify genetic variations that may be associated with complex diseases like schizophrenia.

Question 15

As organisms increase in complexity from yeasts to fruit flies to humans, the number of protein-coding genes in the genome increases _______ than the number of nucleotides, and the proportion of the genome that codes for proteins _______.

Accepted Answer

As organisms become more complex, the number of protein-coding genes increases less than the number of nucleotides, and the proportion of the genome that codes for proteins greatly decreases due to the presence of more non-coding DNA.

Question 16

What percentage of the human genome is DNA that codes for proteins?

Accepted Answer

Only a small fraction of the human genome (less than 5%) codes for proteins. The remaining DNA is either non-coding or has regulatory roles such as controlling gene expression.

Question 17

In which species or population would haplotype mapping be particularly challenging or practically impossible?

Accepted Answer

Haplotype mapping relies on identifying genetic variation within a population. Cheetahs have very little genetic diversity due to a population bottleneck in their recent history, making it very difficult to identify genetic variation and construct haplotypes.

Question 18

Which statement comparing the human genome to those of invertebrates such as Caenorhabditis elegans and Drosophila melanogaster is true?

Accepted Answer

The average human gene can code for more proteins than the average invertebrate gene due to alternative splicing, which allows a single gene to produce multiple proteins.

Question 19

Opsin genes are involved in vision.Which circumstance would most likely lead to the evolution of pseudogenes in the opsins of a salamander?

Accepted Answer

The answer of Opsin genes are involved in vision.Which circumstance...

Question 20

What is the most likely explanation for the abundance of transposons in eukaryotic genomes?

Accepted Answer

Transposons are often referred to as "genomic parasites" because they have a tendency to replicate themselves and insert themselves into new locations within the genome, sometimes disrupting normal gene function.

Quiz 17: Genomes