Q: A population of 1000 individuals has two alleles for a gene: A and a. If the frequency of allele A ($$p) is 0.7 $$and allele a ($$q) is 0.3$$, what is the expected frequency of heterozygotes under Hardy-Weinberg equilibrium?

$$2pq = 2 \times 0.7 \times 0.3 = 0.42$$

Q: If the Gross Primary Productivity (GPP) of a forest is 1000 kcal/m²/year and the energy used in cellular respiration (R) is 550 kcal/m²/year, what is the Net Primary Productivity (NPP)?

$$NPP = GPP - R = 1000 - 550 = 450 \ \text{kcal/m}^2/\text{year}$$

Question 1

Which of the following best describes the Hardy-Weinberg principle?

Accepted Answer

It is a mathematical null hypothesis stating that allele and genotype frequencies remain constant from generation to generation in the absence of evolutionary forces.

Question 2

A population of 1000 individuals has two alleles for a gene: A and a. If the frequency of allele A ($$p) is 0.7 $$and allele a ($$q) is 0.3$$, what is the expected frequency of heterozygotes under Hardy-Weinberg equilibrium?

Accepted Answer

$$2pq = 2 	imes 0.7 	imes 0.3 = 0.42$$

Question 3

Which of the following is NOT an assumption of the Hardy-Weinberg model?

Accepted Answer

Natural selection is acting on the population.

Question 4

In a small population of birds, a rare allele becomes fixed within a few generations. Which evolutionary process most likely explains this observation?

Accepted Answer

Genetic drift

Question 5

Which of the following scenarios is an example of disruptive selection?

Accepted Answer

A population of finches where both small and large beak sizes are favored, but medium beak sizes are selected against.

Question 6

Which of the following best explains why inbreeding increases the frequency of homozygotes but does not cause evolution?

Accepted Answer

Inbreeding changes genotype frequencies but not allele frequencies in the population.

Question 7

Which of the following is an example of balancing selection?

Accepted Answer

Both red and green pea aphids persist in a population because each color has a selective advantage under different predation pressures.

Question 8

Which of the following is a real-world example of the founder effect?

Accepted Answer

A small group of lizards colonizes a new island, and their descendants have different allele frequencies than the original population.

Question 9

Which of the following best describes gene flow?

Accepted Answer

The movement of alleles between populations, which tends to homogenize allele frequencies.

Question 10

Which of the following is a consequence of biomagnification in aquatic food chains, as seen with DDT?

Accepted Answer

Top predators, such as birds of prey, accumulate higher concentrations of DDT, leading to reproductive issues.

Question 11

If the Gross Primary Productivity (GPP) of a forest is 1000 kcal/m²/year and the energy used in cellular respiration (R) is 550 kcal/m²/year, what is the Net Primary Productivity (NPP)?

Accepted Answer

$$NPP = GPP - R = 1000 - 550 = 450 \ 	ext{kcal/m}^2/	ext{year}$$

Question 12

Which of the following factors most often limits the rate of decomposition in boreal forest soils compared to tropical wet forests?

Accepted Answer

Low temperatures and low precipitation in boreal forests slow down decomposition.

Question 13

Which of the following best explains why NPP is generally higher on land than in the open ocean?

Accepted Answer

Nutrient availability, sunlight, and temperature are generally higher and more consistent on land.

Question 14

Which of the following is a direct effect of increased atmospheric CO$$_2$$ due to fossil fuel burning?

Accepted Answer

Increased greenhouse effect leading to global warming.

Question 15

Which of the following is an example of positive feedback in climate change?

Accepted Answer

Melting Arctic ice reduces Earth's albedo, causing more solar energy to be absorbed and further warming.

Question 16

Which of the following best describes the process of nitrogen fixation?

Accepted Answer

Conversion of atmospheric N$$_2$$ into ammonia by bacteria or lightning.

Question 17

A population of 500 plants has the following genotype frequencies: 200 AA, 200 Aa, and 100 aa. What are the allele frequencies for A ($$p) $$and a ($$q$$)?

Accepted Answer

$$p = 0.6, \ q = 0.4$$

Question 18

Which of the following is a likely consequence of inbreeding depression in a small, isolated population?

Accepted Answer

Increased expression of deleterious recessive alleles, leading to reduced fitness.

Question 19

Which of the following best describes sexual selection according to the Bateman-Trivers hypothesis?

Accepted Answer

Females are choosy about mates because they invest more in offspring, while males compete for access to females.

Question 20

Which of the following is a direct effect of ocean acidification caused by increased atmospheric CO$$_2$$?

Accepted Answer

Dissolution of calcium carbonate shells in mollusks and corals.

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