Question 1

The geologist who,in 1830,renewed the idea of uniformitarianism by showing that gradual changes in some organisms could be represented in successive fossil layers was

Accepted Answer

The geologist who renewed the idea of uniformitarianism in 1830 and showed that gradual changes in some organisms could be represented in successive fossil layers was Charles Lyell.

Question 2

An organism's phenotype is

Accepted Answer

An organism's phenotype refers to its observable properties, including its physical characteristics, behavior, and other traits determined by both genetic and environmental factors. It is not solely determined by single genes or traits acquired over the life of the organism, and can be influenced by a wide range of factors.

Question 3

The mode of natural selection in which two or more extreme phenotypes are fitter than the intermediate phenotype is

Accepted Answer

Disruptive (or diversifying) selection favors extreme phenotypes over the intermediate phenotype, leading to divergence of the population into two or more distinct groups. This can occur when different phenotypes are adapted to different aspects of the environment or when individuals with intermediate phenotypes are at a disadvantage in both environments.

Question 4

The relatively short-term changes in allele frequencies within a species or population is

Accepted Answer

The definition accurately describes microevolution, which refers to the genetic changes that occur within a population over a relatively short period of time. Uniformitarianism is a geological theory, artificial selection involves intentional breeding for specific traits, natural selection involves the survival and reproduction of the fittest individuals, and macroevolution refers to larger-scale evolutionary changes over longer periods of time.

Question 5

The three types of natural selection are

Accepted Answer

The three types of natural selection are directional selection, disruptive selection, and stabilizing selection. Option E lists these three types correctly. Option A lists artificial selection as one of the types, but it is not a natural selection process as it is driven by human intervention. Option B lists normalizing selection, which is not a recognized type of natural selection. Option C lists normalizing selection and does not include directional selection, which is a recognized type of natural selection. Option D includes artificial selection, but not directional selection, which is a recognized type of natural selection. Therefore, option E is the best choice.

Question 6

The French naturalist who in 1749 became one of the first scientists to suggest that closely-related species arose from a common ancestor and were changing was

Accepted Answer

While modern evolutionary theory begins in Western Europe,the ancient Greeks had some ideas in the same vein.Please see section 12.2 for more information.

Question 7

At Hardy-Weinberg equilibrium

Accepted Answer

At Hardy-Weinberg equilibrium, allele frequencies remain constant from one generation to the next so evolution does not occur. This means that the genetic makeup of a population is not changing and there is no selection, migration, mutation or genetic drift occurring. Therefore, the population remains stable and does not evolve.

Question 8

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

Accepted Answer

In the Hardy-Weinberg equation, p and q represent the frequencies of the two alleles in a population, and they must add up to 1.

- p^2 represents the frequency of homozygous dominant individuals (AA)
- q^2 represents the frequency of homozygous recessive individuals (aa)
- 2pq represents the frequency of heterozygous individuals (Aa)

Since the equation states that all of these frequencies must add up to 1, 2pq represents the remaining frequency after accounting for homozygous dominant and recessive individuals. Therefore, the best choice is C, which represents the frequency of heterozygous individuals.

Question 9

The mode of natural selection in which one extreme phenotype is fittest and the environment selects against the others is

Accepted Answer

Directional selection favors individuals with extreme phenotypes, which can lead to the evolution of new traits or the loss of existing ones. In this mode of selection, the environment selects against the other phenotypes, leading to a shift in the population towards the extreme phenotype that is fittest. Disruptive selection, on the other hand, favors both extremes and selects against the intermediate phenotype. Stabilizing selection favors the intermediate phenotype and selects against both extremes. Artificial selection is when humans selectively breed animals or plants for desirable traits, and uniformitarianism is a geological theory that describes the slow and steady processes that shape the earth's surface over millions of years.

Question 10

The mode of natural selection in which extreme phenotypes are less fit than the optimal intermediate phenotype is

Accepted Answer

Stabilizing selection favors the optimal intermediate phenotype and tends to eliminate the extreme phenotypes. This type of selection reduces phenotypic variation in a population.

Question 11

A gradual change from an ancestral type was referred to by Darwin as

Accepted Answer

The term "descent with modification" refers to the gradual change from an ancestral type, which is a key concept in Darwin's theory of evolution.

Question 12

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 given gene in the population. The equation assumes that the population is in genetic equilibrium, which means that the frequency of these alleles will remain constant from generation to generation, assuming there is no natural selection, mutation, migration, or genetic drift occurring. If there were more than two alleles or if the trait were polygenic, the equation would not be applicable.

Question 13

The entire collection of genes and their alleles is a population's

Accepted Answer

The gene pool refers to the entire collection of genes and their alleles within a population. The genotype refers to the specific genetic makeup of an individual, while the phenotype refers to the observable traits of an individual. Dominant and recessive traits refer to specific modes of inheritance, not the entire collection of genes within a population.

Question 14

Antibiotic resistance is becoming more common in disease-causing bacteria because

Accepted Answer

All of the given reasons contribute to the increased antibiotic resistance in disease-causing bacteria. The overuse and misuse of antibiotics in both human and animal populations is a major factor in the development of antibiotic resistance. Antibiotics are used in feed for livestock, and they are often prescribed for viral infections due to patient pressure. Some patients do not take the antibiotics as directed, leading to incomplete treatment and potential development of resistant bacteria. In addition, antibiotics are also used to treat infections in animals, which can contribute to the overall spread of antibiotic resistance.

Question 15

The French taxonomist who,in 1809,was the first scientist to suggest that organisms that use one part of their body repeatedly would increase their abilities was

Accepted Answer

The idea described in the question is known as Lamarckism, after the French taxonomist Jean Lamarck. Charles Darwin and Alfred Russel Wallace developed the theory of evolution through natural selection, which differed from Lamarckism in several key ways. Georges Buffon was a contemporary of Lamarck's, but did not propose the idea described in the question. Charles Lyell was a geologist, not a biologist.

Question 16

According to Darwin,natural selection usually

Accepted Answer

According to Darwin's theory of natural selection, individuals with favorable variations that enable them to better survive and reproduce are more likely to pass on their traits to the next generation. Meanwhile, individuals with harmful variations that reduce their chances of survival and reproduction are less likely to pass on their traits. Therefore, natural selection preserves favorable variations and rejects harmful variations in a population.

Question 17

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

Accepted Answer

Immigration and emigration can disrupt Hardy-Weinberg equilibrium by introducing new alleles or removing existing ones from the population. This changes the allele frequencies, and therefore violates the assumption that the population is not evolving under the influence of external forces.

Question 18

Individuals whose red blood cells are the correct shape and are able to resist malaria have a better chance of reaching reproductive age.This is known as

Accepted Answer

Heterozygote advantage is when individuals carrying two different alleles for a gene have a higher fitness than individuals carrying only one allele or the other. In this case, individuals carrying both the normal and the sickle cell hemoglobin allele (heterozygous) have an advantage in resisting malaria compared to those carrying only the normal allele (homozygous) or the sickle cell allele (homozygous). This leads to a higher rate of survival and reproduction for heterozygotes, which can result in an increase in the frequency of the heterozygous genotype in the population over time, thus providing an evolutionary advantage.

Question 19

The scientist who published "On the Origin of Species by Means of Natural Selection" in 1859 was

Accepted Answer

"On the Origin of Species by Means of Natural Selection" was published by Charles Darwin in 1859.

Question 20

Genetic change in a population through multiple generations defines which of the following?

Accepted Answer

Genetic change in a population through multiple generations defines evolution. Heredity refers to the passing down of traits from parents to offspring, mitosis is a form of cell division, phenotype refers to the physical characteristics of an individual, and genotype refers to the genetic makeup of an individual.

Quiz 12: Forces of Evolutionary Change