Question 1

What is a point mutation that does NOT result in a change to the amino acid for which it is coded?

Accepted Answer

A synonymous mutation is a point mutation that does not result in a change to the amino acid for which it is coded. Instead, it codes for the same amino acid as before, due to the redundancy of the genetic code.

Question 2

How can humans become infected with malaria?

Accepted Answer

Malaria is caused by the transmission of the Plasmodium parasite from an infected mosquito to a human host while feeding on their blood. This is the primary mode of transmission. Drinking bad water or eating spoiled food does not transmit the disease. There is no evidence to suggest that malaria is caused by a genetic mutation.

Question 3

What are all of the alleles contained within a group of interbreeding individuals together known as?

Accepted Answer

A group of interbreeding individuals together is known as a population. The total sum of all the alleles at all gene loci in a population is called the gene pool. Therefore, A is the correct answer. Choice B describes the group of individuals, but not their genetic variation. Choice C refers to a gradual change in traits across a geographic region. Choice D refers to the presence of multiple alleles at a particular gene locus within a population.

Question 4

Australian aborigines are an endogamous society.This means that marriage and reproduction take place within the group.What does this lead to?

Accepted Answer

Endogamy typically leads to decreased genetic diversity due to a lack of admixture with other populations. Since marriage and reproduction take place within the group, there is limited genetic input from outside the group, resulting in a more homogenous gene pool.

Question 5

The type of selection that favored progressively larger brain size in human evolution is ________ selection.

Accepted Answer

Directional selection is a type of natural selection that favors individuals with traits that are at one extreme of the distribution. In the case of human evolution, larger brain size was a trait that provided a selective advantage, leading to directional selection favoring individuals with progressively larger brain sizes over time.

Question 6

The southern migration of which African people may have led to a significant increase in the incidence of malaria?

Accepted Answer

The Bantu people are known to have migrated southward in Africa around 1,500 BCE, settling in areas where malaria was endemic. With their settlement, the incidence of malaria increased due to their lack of immunity to the disease. This is evidenced by the high prevalence of sickle cell traits in Bantu populations, which is a genetic adaptation to malaria. The other options (Masai, Turkana, and Efe) are not known to have migrated in a way that significantly affected the incidence of malaria.

Question 7

What is the cause of the significant difference between the ABO and MN blood-type frequencies of the Dunkers and those of current American and German populations?

Accepted Answer

Genetic drift is the random fluctuation of allele frequencies in a small population. The Dunkers are a closed community that has undergone significant genetic drift, leading to a difference in their ABO and MN blood-type frequencies compared to the larger American and German populations. This is not likely due to natural selection as there is no known advantage or disadvantage associated with ABO and MN blood types. Gene flow and mutation may also influence allele frequencies, but they are less likely to cause such a significant difference in a small, isolated population.

Question 8

What is the physical location of a gene within the genome called?

Accepted Answer

The physical location of a gene within the genome is called its locus. A locus refers to the specific location of a gene on a chromosome or within a genome.

Question 9

Transposable elements are DNA sequences that:

Accepted Answer

Transposable elements are capable of moving to different locations within a genome, either by replicating themselves and inserting the copy at a new site, or by excising and reinserting themselves elsewhere in the genome. Therefore, option D is the correct choice. Options A, B, and C do not accurately describe transposable elements.

Question 10

Some genetic disorders decrease susceptibility to malaria.What is an example of a genetic disorder that has this effect?

Accepted Answer

G6PD deficiency, also known as favism, decreases susceptibility to malaria by causing hemolysis (destruction of red blood cells), making it difficult for the malaria parasite to survive in the body. This genetic disorder is most commonly found in individuals of Mediterranean or African descent.

Question 11

When individuals of the same species are reproductively isolated,genetic differences may accumulate in sufficient number so that new species could emerge.What would such an event be an example of?

Accepted Answer

The event described in the question is an example of macroevolution, which refers to large-scale evolutionary changes, such as the emergence of new species. Reproductive isolation is a key factor in the formation of new species, as it allows genetic differences to accumulate and potentially give rise to distinct populations that can no longer interbreed. Neither spontaneous mutation, balanced polymorphism, nor equilibrium fully capture the significance and complexity of this evolutionary process.

Question 12

Which of the evolutionary forces is most likely to decrease variation between populations?

Accepted Answer

Gene flow occurs when individuals move from one population to another, bringing their genes with them. This can decrease the genetic differences between populations, making them more similar. Therefore, gene flow is the evolutionary force most likely to decrease variation between populations.

Question 13

In certain species of nonhuman primates there are groups where only one dominant female has access to mates.The other females must wait until the opportunity to mate presents itself.This will have direct impact on "fitness," influencing which of the following?

Accepted Answer

The dominant female's exclusive access to mates means that the reproductive success of the other females in the group will be impacted, as they must wait for an opportunity to mate. This means that the dominant female will likely have higher reproductive success than the other females in the group, given that she can mate whenever she wants. Therefore, choice A, reproductive success, is the best option. Choices B, C, and D are not directly impacted by the exclusivity of the dominant female's access to mates.

Question 14

Evolution is complicated and manifest in many ways,but at the root of it all physical anthropologists define it as:

Accepted Answer

Physical anthropologists define evolution as a change in allele frequencies in a breeding population over time, which can lead to the development of new species. This definition encompasses the gradual changes that occur over time, rather than sudden changes in an individual's DNA or short-term processes.

Question 15

Mutations in DNA found in which cells are most likely to have significant evolutionary consequences?

Accepted Answer

Mutations in cells that produce gametes (such as sperm and egg cells) directly affect the genetic makeup of the offspring and can potentially lead to significant evolutionary changes over time. Mutations in other cells may have little impact on evolution.

Question 16

What is likely the cause of the clinal decrease in type B blood from East Asia to Western Europe?

Accepted Answer

Gene flow, or the movement of individuals and their genes from one population to another, is the most likely cause of the clinal decrease in type B blood from East Asia to Western Europe. This is because populations that are geographically closer are more likely to exchange genes than those that are farther apart. As a result, gene flow can lead to a decrease in the frequency of certain alleles or traits in a particular population over time.

Question 17

While conducting research with a small population in South America,you note that an overwhelming majority of individuals exhibit signs of a specific genetic abnormality.What is most likely the cause of this?

Accepted Answer

The founder effect occurs when a small group of individuals from a larger population colonize a new area. The new population may have reduced genetic diversity, and certain traits or genetic abnormalities may become more common due to chance. This could explain why there is an overwhelming majority of individuals exhibiting a specific genetic abnormality in this small population in South America.

Question 18

What is another name for the evolutionary force called gene flow?

Accepted Answer

Admixture is another name for gene flow. Admixture refers to the incorporation of genetic material from one population into another population through interbreeding. This process can occur when individuals from different populations come together and mate, or when a population expands and individuals disperse to new areas. Gene flow can introduce new genetic variants into a population, which can increase genetic diversity and potentially change the genetic makeup of the population over time.

Question 19

What does the Hardy-Weinberg law of equilibrium assume?

Accepted Answer

The Hardy-Weinberg law of equilibrium assumes no gene flow, mutation, or natural selection.

Question 20

How do we know that Upper Paleolithic food foragers in Europe are ancestors to modern European populations?

Accepted Answer

Recent genetic research has shown that Upper Paleolithic food foragers in Europe are ancestors to modern European populations based on comparisons of DNA from ancient skeletal remains with DNA from living Europeans.

Quiz 4: Genes and Their Evolution: Population Genetics