Question 1

Which genetic mechanism is primarily responsible for breaking up linkage disequilibrium (LD) between markers in a population?

Accepted Answer

Recombination

Question 2

In a population with high levels of inbreeding, how does the decay of linkage disequilibrium (LD) compare to that in a randomly mating population?

Accepted Answer

LD decays slower in inbred populations

Question 3

Which of the following best describes a 'run of homozygosity' (ROH)?

Accepted Answer

A region of the genome where consecutive DNA markers are uniformly homozygous

Question 4

Which equation best describes the exponential distribution of autozygous segment lengths since a common ancestor?

Accepted Answer

$$f(x) = \frac{1}{\lambda} e$$^{-x/\lambda}$$

Question 5

A selective sweep is most likely to be detected in a population when:

Accepted Answer

A beneficial, heritable trait increases in frequency, carrying linked alleles with it

Question 6

Which of the following is a method used to detect levels of autozygosity or signatures of selection in a genome?

Accepted Answer

Runs of Homozygosity (ROH)

Question 7

If a population undergoes a selective sweep for lactose tolerance, what pattern would you expect to see in the region surrounding the lactase gene (LCT)?

Accepted Answer

A long run of homozygosity with reduced genetic variation

Question 8

Which of the following factors generally has the smallest effect on linkage disequilibrium (LD) in a large population?

Accepted Answer

Genetic drift

Question 9

What is the primary difference between autozygous ROH and a selective sweep ROH?

Accepted Answer

Autozygous ROH are due to inheritance of identical segments from both parents, while selective sweep ROH are due to positive selection

Question 10

Which of the following best describes the effect of migration (gene flow) on linkage disequilibrium (LD) in genetically distinct populations?

Accepted Answer

It increases LD by introducing new non-random associations

Question 11

Which of the following mating strategies is most likely to increase the length and number of ROH in the offspring?

Accepted Answer

Line-breeding

Question 12

A population geneticist observes a long ROH in an individual. What is the most likely explanation?

Accepted Answer

The individual's parents are highly related (recent inbreeding)

Question 13

Which of the following equations would you use to calculate the frequency of the B allele in a population, given genotype frequencies?

Accepted Answer

$$f(B) = f(BB) + \frac{1}{2} f(Bb)$$

Question 14

Which genomic approach is best suited for visualizing the relationship of individuals and population structure?

Accepted Answer

Principal Component Analysis (PCA)

Question 15

Why is it difficult to distinguish an autozygous ROH from a selective sweep ROH?

Accepted Answer

Both result in long homozygous regions with reduced genetic variation

Question 16

Which of the following is NOT a factor that can affect patterns of linkage disequilibrium (LD) in a population?

Accepted Answer

Mitochondrial inheritance

Question 17

A dog breeder wants to maintain genetic diversity and reduce inbreeding in their kennel. Which strategy should they prioritize?

Accepted Answer

Outcrossing

Question 18

Which of the following statements about linkage disequilibrium (LD) is correct?

Accepted Answer

LD can be broken down by recombination events

Question 19

Which of the following best describes the concept of 'hitchhiking' in the context of a selective sweep?

Accepted Answer

Neutral alleles linked to a beneficial allele increase in frequency due to selection on the beneficial allele

Question 20

Which of the following is a real-world example of a selective sweep in humans?

Accepted Answer

The increase in frequency of the lactase persistence allele in populations with a history of dairy farming

Linkage Disequilibrium, Runs of Homozygosity, and Population Structure in Genetics

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