Question 1

Genetic variation refers to

Accepted Answer

Genetic variation refers to the differences between individuals caused by the genes they inherit. This variation results in unique traits and characteristics that distinguish individuals from one another.

Question 2

According to the hypothesis the specific language impairment (SLI) can be caused by a dominant gene at a single locus, what is the probability that an individual who has SLI and an individual without it will have a child with SLI?

Accepted Answer

If SLI is caused by a dominant gene at a single locus, then an individual with SLI would simply be homozygous or heterozygous for the dominant allele at that locus, while an individual without SLI would be homozygous for the recessive allele. When these two individuals have a child, the child would inherit one allele from each parent, and therefore would have a 50% chance of inheriting the dominant SLI allele and thus developing SLI.

Question 3

Scientists conventionally divide human variation into which two components?

Accepted Answer

Human variation can be divided into genetic and environmental factors, with genetic factors referring to differences in DNA sequence between individuals and environmental factors referring to differences in the physical, social, and cultural environment in which individuals live. This division is widely recognized among scientists studying human variation.

Question 4

Variation refers to

Accepted Answer

Variation can refer to any kind of differences between individuals or populations of individuals, including genetic, environmental, and cultural differences.

Question 5

Non-insulin-dependent diabetes

Accepted Answer

Non-insulin-dependent diabetes, also known as Type II diabetes, has a strong genetic basis. However, lifestyle factors such as diet and exercise also play a significant role in its development. It is not a maladaptive trait, as it has not always existed in human populations and is likely an adaptation to changes in diet and physical activity patterns. It does not cause iron levels to rise above normal.

Question 6

The evolution of lactase persistence in Africa and Europe was the result of

Accepted Answer

The evolution of lactase persistence in Africa and Europe was the result of convergent adaptation. This is because in these two regions, humans independently adapted to consuming milk as a source of nutrition after the domestication of animals like cows, goats, and sheep. Lactase persistence is the ability to digest lactose, the sugar found in milk, into adulthood.

Question 7

Sickle-cell anemia

Accepted Answer

Sickle-cell anemia is caused by a genetic mutation that produces an abnormal form of hemoglobin, the protein that carries oxygen in red blood cells. This abnormal hemoglobin causes red blood cells to become C-shaped, like a sickle, instead of the normal disc-shaped cells. These sickle cells can block blood flow, leading to pain, organ damage, and an increased risk of infections.

Question 8

Where Plasmodium falciparum malaria is present, AS infants are about ________ more likely to reach adulthood than AA infants.

Accepted Answer

The answer of Where Plasmodium falciparum malaria is present, AS...

Question 9

If parents and offspring resemble each other, similarities are likely due to

Accepted Answer

Similarities between parents and offspring are typically due to a combination of shared genes, environments, and culture, as all these factors contribute to familial resemblance.

Question 10

The FOXP2 gene

Accepted Answer

FOXP2 is a gene that shows evidence of directional selection in humans, meaning it has changed significantly over time in response to some selective pressure. It has been linked to language ability and may have played a role in the evolution of human speech.

Question 11

Physical traits such as weight

Accepted Answer

Physical traits such as weight are determined by a combination of genetic, environmental, and cultural factors. Genetics can predispose individuals to certain body types, but environmental factors such as diet and exercise can also play a significant role in determining weight. Additionally, cultural practices such as food choices and body ideals can influence weight as well. Therefore, physical traits such as weight cannot be solely attributed to genetics or cultural practices.

Question 12

Tay-Sachs disease may give partial resistance to tuberculosis

Accepted Answer

Heterozygous individuals for Tay-Sachs disease have been observed to have partial resistance to tuberculosis. This may be an example of a balanced polymorphism, where the harmful Tay-Sachs allele is maintained in the population due to its protective effects against tuberculosis. Additionally, Tay-Sachs disease occurs at a higher rate in Western European Jewish populations than in other Jewish populations.

Question 13

Human groups from different regions around the world

Accepted Answer

Different human groups from around the world can differ in terms of the genetic diseases that affect them. For example, sickle cell anemia is more common in people of African descent, while thalassemia is more common in people of Mediterranean, Middle Eastern, and Southeast Asian descent. Therefore, although there may be some overlap, human groups from different regions do vary in terms of genetic diseases.

Question 14

The normal version of the FOXP2 gene spread throughout human populations less than

Accepted Answer

Studies show that the normal version of the FOXP2 gene originated in humans about 200,000 years ago and became ubiquitous in human populations around that time.

Question 15

Evidence or proof that a trait is caused by a single gene includes

Accepted Answer

Observing Mendelian inheritance patterns is the best evidence or proof that a trait is caused by a single gene. This is because Mendelian inheritance follows predictable patterns of inheritance based on the dominant and recessive nature of genes. If a trait follows a Mendelian pattern of inheritance, it suggests that only one gene is responsible for the expression of that trait.

Question 16

Physical traits such as weight are

Accepted Answer

Physical traits such as weight are influenced by both genetic and environmental factors. Genetic factors may predispose an individual to being overweight, while environmental factors such as diet and exercise can also impact weight. Therefore, weight is determined by an interaction between genes and the environment.

Question 17

Environmental variation includes factors such as

Accepted Answer

Environmental variation refers to differences in the environment that can affect individuals within a population. This includes factors such as climate, topography, and availability of resources. Choices A and B refer to individual characteristics and are not factors that contribute to environmental variation. Choice C refers to genetic variation within a population, which is related but distinct from environmental variation. Therefore, the best choice for factors that contribute to environmental variation is D, differences in climate.

Question 18

We know that milk production played an important role in early pastoral communities in northern Europe because

Accepted Answer

Analyses of pottery show residues of compounds found only in milk, indicating that milk production played an important role in early pastoral communities in northern Europe.

Question 19

Which of the following is (are) example(s) of variation among groups?

Accepted Answer

Variation among groups refers to differences that exist between distinct populations or groups. Tay-Sachs disease is more prevalent in certain Jewish populations, making it an example of variation among groups.

Question 20

Environmental variation refers to

Accepted Answer

The answer of Environmental variation refers to
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Quiz 14: Human Genetic Variation