Q: If a heterozygous individual (Aa) has four children, what is the probability that exactly two children inherit the A allele?

$$P = 6 \times (0.5)^4$ = 0.375$$

Question 1

Which of the following best describes genetic drift?

Accepted Answer

A random fluctuation in allele frequencies over time due to chance events.

Question 2

In a population of 10 alleles (5 individuals), if the initial frequency of allele A is $$p = 0.5$$, what is the expected number of A alleles in the next generation due to genetic drift?

Accepted Answer

$$5$$

Question 3

Which of the following statements about genetic drift is FALSE?

Accepted Answer

Genetic drift always increases genetic variation within a population.

Question 4

If a heterozygous individual (Aa) has four children, what is the probability that exactly two children inherit the A allele?

Accepted Answer

$$P = 6 	imes (0.5)^4$ = 0.375$$

Question 5

In a simulation of genetic drift with $$N = 50$$ individuals and initial allele frequency $$p = 0.5$$, which outcome is most likely after many generations?

Accepted Answer

The allele will eventually become either fixed ($$p = 1) or $$extinct ($$p = 0).$$

Question 6

Which of the following best explains why genetic drift has a stronger effect in small populations?

Accepted Answer

Sampling deviations are larger in small populations, leading to greater fluctuations in allele frequencies.

Question 7

A population starts with allele frequency $$p = 0.5. $$After 27 generations, the frequency of allele A is $$p = 1.0. $$What has occurred?

Accepted Answer

Allele A has become fixed in the population.

Question 8

In the context of genetic drift, what does 'fixation' mean?

Accepted Answer

An allele has reached a frequency of $$p = 1 in $$the population.

Question 9

If you simulate genetic drift multiple times with the same starting allele frequency and population size, what is the most likely observation?

Accepted Answer

Each simulation will show different patterns of allele frequency change due to randomness.

Question 10

Which of the following scenarios is an example of a sampling effect leading to genetic drift?

Accepted Answer

A small group of individuals founds a new population, and by chance, some alleles are not represented.

Question 11

Given a population of 4 children from a heterozygous parent (Aa), what is the probability that all four children inherit the a allele?

Accepted Answer

$$P = (0.5)^4$ = 0.0625$$

Question 12

Why does Hardy-Weinberg equilibrium assume an infinite population size?

Accepted Answer

To eliminate sampling deviations that cause allele frequencies to fluctuate by chance.

Question 13

Which of the following is a correct application of the 'and rule' in probability as used in genetic drift calculations?

Accepted Answer

Multiplying the probability of each independent event to find the probability of all events occurring together.

Question 14

If a population of 50 reproductive adults is simulated for 100 generations with an initial allele frequency $$p = 0.5$$, what is the most likely long-term outcome for the allele?

Accepted Answer

The allele will eventually become either fixed ($$p = 1) or $$extinct ($$p = 0).$$

Question 15

Which of the following best describes the effect of genetic drift on genetic variation within a population over time?

Accepted Answer

It tends to decrease genetic variation by leading to fixation or extinction of alleles.

Question 16

A simulation of genetic drift in a population of $$N = 5$$ individuals starts with $$p = 0.5. $$After three generations, the allele frequencies are $$p = 0.6$$, $$p = 0.5$$, and $$p = 0.4. $$What does this illustrate?

Accepted Answer

Allele frequencies can fluctuate randomly from generation to generation.

Question 17

Which of the following is NOT a possible outcome of genetic drift in a finite population?

Accepted Answer

The allele frequency remains exactly the same in every generation.

Question 18

In the context of genetic drift, what is the significance of the 'or rule' in probability?

Accepted Answer

It is used to add the probabilities of mutually exclusive events to find the total probability.

Question 19

Why does genetic drift eventually lead to fixation or extinction of alleles in a population?

Accepted Answer

Random sampling causes allele frequencies to fluctuate until one allele reaches a frequency of 1 or 0.

Genetic Drift: Random Fluctuations in Allele Frequencies

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