Wk4-Starter-Block2-12ASP-2023-2024

Which of the following statements is accurate with regard to a population in Hardy-Weinberg equilibrium?

• Natural selection, gene flow, and genetic drift are acting equally to change allele frequencies.

• Allele frequencies should not change from one generation to the next.

• Two alleles are present in equal proportions.

• Individuals within the population are evolving.

Which of the following statements about genetic variation is accurate?

• Genetic variation is created by the direct action of natural selection.

• Genetic variation arises in response to changes in the environment.

• Genetic variation must be present in a population before natural selection can act upon the population.

• Genetic variation tends to be reduced when diploid organisms produce gametes.

16% of the population is unable to taste the chemical PTC. These non-tasters are recessive for the tasting gene.

1. 1. What percentage of individuals in the population are tasters?

2. 2. What is the frequency of the dominant and recessive allele?

3. 3. What percentage of the population are heterozygous for the trait?

Show the working in your biology notebook.

Answer explanation

Reference video:

https://www.youtube.com/watch?v=xPkOAnK20kw

Which of the following situations leads to microevolution?

• An individual bird has a beak of a particular size that grows larger during a drought.

• Mutations in muscle cells are transferred to the next generation.

• Alleles move between populations that differ in allele frequencies.

• All individuals within a population have the same allele at a particular locus.

A hypothetical population of 10,000 humans has 6840 individuals with the blood type AA, 2860 individuals with blood type AB and 300 individuals with blood type BB. Using this information calculate the following:

a. the frequency of each genotype in this population.

 

 

b. the frequency of the “A” allele.

 

 

 

c. the frequency of the “B” allele.

 

d. if the next generation contained 25,000 individuals, how many individuals would have blood type BB assuming the population is in Hardy-Weinberg equilibrium?

Show the working in your biology notebook.

Cystic fibrosis is a genetic disorder in humans where the person has two homozygous recessive alleles for the gene. If the disease is left untreated, it causes severe health problems in the individual. If 9 in 10,000 newborn babies have the disease, what are the expected frequencies of the dominant (A1) and recessive (A2) alleles according to the Hardy-Weinberg equation? SHOW YOUR WORKING IN YOUR BIOLOGY NOTEBOOK

Bloom's Taxonomy:  Levels 3-4: Applying/Analyzing

• f(A1) = 0.9997, f(A2) = 0.0003

• f(A1) = 0.9800, f(A2) = 0.0200

• f(A1) = 0.9700, f(A2) = 0.0300

• f(A1) = 0.9604, f(A2) = 0.0392