Question 1

The Black Death was a pandemic spreading across Europe between 1348 and 1350.Estimates state that 30% to 60% of Europe's population died from the Black Death.If we look at Europe's population before the pandemic and compare it to the population several generations later,what are we likely to find?

A)More genetic diversity in later generations
B)Less genetic diversity in later generations
C)Less genetic diversity in earlier generations
D)The same degree of genetic diversity in later as in earlier generations

Accepted Answer

The Black Death wiped out a significant portion of Europe's population, resulting in a bottleneck effect. This means that only a small portion of the original population survived to pass on their genes to future generations, resulting in less genetic diversity in later generations.

Question 2

Which term refers to a random change in allele frequencies,not based on natural selection?&#10;A)Population bottleneck&#10;B)Genetic drift&#10;C)Founder effect&#10;D)Migration effect

Accepted Answer

Genetic drift is the random change in allele frequencies within a population, not related to selective pressures, that can occur due to chance events such as founder effects, population bottlenecks, or migration.

Question 3

Which practice is most likely to result in a change in the Hardy-Weinberg equilibrium of a population or geographic area?&#10;A)Random mating from within the established population&#10;B)Geographic isolation of the established population&#10;C)Assimilation of immigrants into the existing population&#10;D)Preponderance of autosomal dominant traits in the existing population

Accepted Answer

Assimilation of immigrants into the existing population is most likely to result in a change in the Hardy-Weinberg equilibrium of a population or geographic area. This is because it introduces new alleles into the population, potentially changing the frequency of existing alleles and disrupting the equilibrium. Random mating, geographic isolation, and the preponderance of autosomal dominant traits in the existing population would not necessarily change the allele frequencies in the population and therefore would not disrupt the equilibrium.

Question 4

A group of eight space travelers,four men and four women,settled on the planet Zebulon.Their descendents had a very high rate of the autosomal dominant disorder,Moonophilia distractens.What factor could explain this phenomenon?

A)Equal exposure to an environmental mutagen
B)Hardy-Weinberg equilibrium
C)Variable expressivity
D)Founder effect

Accepted Answer

The high rate of the autosomal dominant disorder, Moonophilia distractens, among the descendants of the eight space travelers suggests that the disorder may have arisen due to a founder effect. This is because the initial population on Zebulon was derived from a small number of founders (eight people) carrying a specific genetic variation. Over time, due to random genetic drift, the frequency of the mutated gene increased among the descendants, leading to a high prevalence of the disorder. A founder effect is a result of genetic isolation and small population size, and can result in the fixation of genetically distinct traits in a population.

Question 5

What pieces of genetic information tend to be passed down from generation to generation with the least variation?&#10;A)Mitochondrial DNA&#10;B)Nuclear DNA&#10;C)Ribosomal DNA&#10;D)Histone proteins

Accepted Answer

Mitochondrial DNA is typically inherited maternally and has a relatively low mutation rate. It is also not subject to recombination during meiosis, meaning that it is passed down intact from mother to offspring. Nuclear DNA, on the other hand, is subject to recombination and has a higher mutation rate, leading to more variation between individuals. Ribosomal DNA and histone proteins are involved in gene expression and regulation, but are not passed down in a consistent manner from generation to generation.

Question 6

Which statement regarding genetic diversity is most accurate?&#10;A)Larger genes are more likely to display diversity than small genes.&#10;B)Genetic diversity is significant only when a population is isolated.&#10;C)Genetic disorders are more common in populations that have greater genetic diversity.&#10;D)Population bottlenecks result in loss of alleles that provide minimal selection advantage.

Accepted Answer

Genetic diversity in the form of single-nucleotide polymorphisms is much more common in alleles of larger genes than those of smaller genes (one sequence variation for every 200 to 500 nucleotides). Lack of genetic diversity occurs in isolated populations. Genetic disorders are more common in populations with less genetic diversity. When diversity is greater, there are more alleles for genes, reducing the likelihood of inheriting two alleles that cause disease or disorders. When population bottlenecks occur, alleles are lost randomly, without regard to whether the allele confers a selection advantage or not.

Question 7

Why is it important to consider population genetics?&#10;A)Natural selection can increase genetic diversity.&#10;B)Accurate assessment of a person's ethnicity can be identified from DNA.&#10;C)Disease risk can vary as a result of the geographic origin of one's ancestors.&#10;D)Knowing ethnicity allows accurate prediction of Huntington disease risk.

Accepted Answer

Population genetics is important because disease risk can vary as a result of geographic origin, which can affect genetic variation and predisposition to certain conditions. By understanding population genetics, medical professionals can tailor treatments and preventative measures to individuals based on their genetic profile, enhancing personalized medicine.

Deck 18: Genetic and Genomic Variation