Question 1

If an environment changes rapidly,organisms with ____ will be more likely to survive and reproduce.

Accepted Answer

Existing beneficial mutations are more likely to survive and reproduce in a rapidly changing environment because they provide an advantage to the organism.

Question 2

In the Hardy-Weinberg equation,p² + 2pq + q² = 1.If the dominant allele frequency is 0.8 what percent of the population will be heterozygous?

Accepted Answer

The frequency of the dominant allele (p) is 0.8, so the frequency of the recessive allele (q) is 0.2. The heterozygous frequency is calculated as 2pq = 2(0.8)(0.2) = 0.32, or 32%.

Question 3

Alleles conferring red plumage to cardinal males are common because red plumage:

Accepted Answer

Red plumage is preferred by female cardinals in choosing a mate. This is supported by studies that have shown that female cardinals prefer males with brighter, redder plumage, as it is an indicator of the male's health and genetic quality. Therefore, alleles conferring red plumage are more likely to be passed on to offspring, as they increase the male's likelihood of mating and reproducing.

Question 4

Ancestors of the Galapagos finches had two different types of seeds to eat on some islands.Some seeds were very small,and required small beaks to handle,other seeds were very large and required large strong beaks to crack.This led to ____ among the Galapagos finches.

Accepted Answer

The fact that the two types of seeds require two different beak sizes means that natural selection is favoring birds with either small beaks or large, strong beaks. This leads to disruptive selection, as the population evolves to have two distinct beak sizes.

Question 5

Darwin made which observation while on his four-year voyage on the Beagle?

Accepted Answer

Darwin observed that organisms are varied and some variations are inherited during his four-year voyage on the Beagle.

Question 6

A cigarette smoker with lung cancer will not pass any smoking-induced lung cancer mutations to his children because the smoking-induced mutations:

Accepted Answer

Smoking-induced mutations would be in somatic cells, which are not involved in the production of reproductive cells (gametes). Therefore, these mutations would not be passed on to the smoker's offspring.

Question 7

Carriers of cystic fibrosis have some protection against intestinal infections such as cholera.However,people with two copies of the cystic fibrosis allele develop a life-threatening disease.The mutant allele is very common in people of northern European descent because of:

Accepted Answer

The answer of Carriers of cystic fibrosis have some protection...

Question 8

Sexually dimorphic features do not include:

Accepted Answer

Intelligence is not a physical trait that varies between sexes and is not considered a sexually dimorphic feature. The rest of the answer choices (A, C, and D) are all examples of physically observable traits that differ between males and females of a species. Option E is incorrect as there are sexually dimorphic features.

Question 9

Hardy-Weinberg equilibrium will not occur in a population in which:

Accepted Answer

Immigration and emigration can change allele frequencies in a population, disrupting the Hardy-Weinberg equilibrium.

Question 10

In the Hardy-Weinberg equation,p² + 2pq + q² = 1: 2pq represents:

Accepted Answer

In the Hardy-Weinberg equation, p represents the frequency of the dominant allele and q represents the frequency of the recessive allele. The term 2pq represents the frequency of heterozygous individuals in the population, where p and q are the frequencies of the two alleles. Therefore, option C is the correct answer.

Question 11

One concern of conservation biologists is that endangered species will have low genetic diversity due to a small population size.Why is this a concern?

Accepted Answer

Low genetic diversity in endangered species can make them vulnerable to diseases, as there may not be individuals with the necessary genetic variation to resist the disease. If all individuals have similar alleles, the entire population can be wiped out by a single disease.

Question 12

Ancestors of giraffes with shorter necks could not reach branches high up in trees for food.This led to ____ for longer necked giraffes.

Accepted Answer

Directional selection describes the process by which a particular phenotype is favored over other phenotypes, resulting in the allele frequency shift toward the favored phenotype. In this case, giraffes with longer necks were favored as they were able to reach higher up branches for food, leading to an increase in the frequency of the allele responsible for the longer neck trait over time.

Question 13

Babies that are at a low birth weight are more likely to have health problems,while women will have difficulty delivering babies with high birth weight.Together this leads to ______ for babies of average birth weight.

Accepted Answer

Stabilizing selection is a type of natural selection that favors individuals with traits that are closer to the average of the population, rather than extreme traits. In this case, babies with average birth weight will have a higher chance of survival and reproductive success than babies with either low or high birth weight. This leads to stabilizing selection, where the population is being stabilized around the average birth weight.

Question 14

Darwin read which of the following in the Essay on the Principle of Population by Malthus?

Accepted Answer

Darwin read about the concept of overpopulation and the struggle for survival in Malthus' "Essay on the Principle of Population". This idea of more individuals being born than can survive to reproduce was key to Darwin's understanding of natural selection.

Question 15

In the Hardy-Weinberg equation,p² + 2pq + q² = 1.If the dominant allele frequency is 0.8,what percent of the population will be homozygous recessive?

Accepted Answer

The frequency of the recessive allele (q) is 1 - 0.8 = 0.2. The percentage of the population that is homozygous recessive is q^2 = (0.2)^2 = 0.04, or 4%.

Question 16

Farmers and horticulturalists bred broccoli,cauliflower,kale,and cabbage from the wild mustard plant through _____.

Accepted Answer

Farmers and horticulturalists intentionally selected and bred individuals with desired traits, such as larger heads or different colors, to create new varieties of broccoli, cauliflower, kale, and cabbage. This process is known as artificial selection. Natural selection, genetic drift, and sexual selection do not accurately describe the process by which these plants were bred. Evolution as a term could be more broadly defined as the change in genetic composition of a population over time, but it does not specifically refer to the intentional breeding of organisms by humans.

Question 17

In the Hardy-Weinberg equation,p² + 2pq + q² = 1.If the dominant allele frequency is 0.8,what percent of the population will be homozygous dominant?

Accepted Answer

According to the Hardy-Weinberg equation, p2 represents the frequency of homozygous dominant individuals. If the dominant allele frequency (p) is 0.8, then p2 would be (0.8)2 = 0.64 or 64%. Therefore, 64% of the population will be homozygous dominant.

Question 18

At Hardy-Weinberg equilibrium:

Accepted Answer

The Hardy-Weinberg equilibrium states that in a non-evolving population, the frequency of alleles and genotypes will remain constant from generation to generation. Therefore, the allele frequencies do not change, and evolution does not occur.

Question 19

Darwin concluded from his observations of nature and readings that:

Accepted Answer

Darwin's theory of natural selection suggests that individuals compete for limited resources, and those best adapted to their environment are more likely to survive and reproduce, passing on advantageous traits to the next generation.

Question 20

In the Hardy-Weinberg equation,p + q = 1,p and q represent the frequency of alleles in a population of diploid organisms if:

Accepted Answer

The Hardy-Weinberg equation assumes that only two alleles exist for a particular gene in the population. The equation predicts the frequencies of these alleles in the gene pool based on the assumption of random mating, no mutations, no migration, no natural selection, and infinitely large population size. Therefore, p and q represent the frequency of dominant and recessive alleles, respectively, and they must add up to 1.

Quiz 11: The Forces of Evolutionary Change