Question 1

Which of the following best describes epistasis in gene interaction?

Accepted Answer

One gene masking or modifying the expression of another gene at a different locus.

Question 2

A dihybrid cross between two heterozygotes ($$AaBb 	imes AaBb) $$produces offspring with a 9:7 phenotypic ratio. Which genetic phenomenon most likely explains this result?

Accepted Answer

Complementary gene interaction (duplicate recessive epistasis)

Question 3

Which equation correctly represents the Hardy-Weinberg equilibrium for a gene with two alleles, $$A$$ and $$a$$, with frequencies $$p$$ and $$q$$?

Accepted Answer

$$p^2 + 2pq$$ + $$q^2 = 1$

Question 4

A population of 1000 individuals has 360 $$AA$$, 480 $$Aa$$, and 160 $$aa$$ genotypes. What is the frequency of allele $$A$$?

Accepted Answer

$$0.6$$

Question 5

Which of the following scenarios best illustrates genetic linkage?

Accepted Answer

Two genes located close together on the same chromosome are inherited together more often than expected by chance.

Question 6

During meiosis, crossing over occurs between homologous chromosomes. What is the primary consequence of this process?

Accepted Answer

It generates new combinations of alleles, increasing genetic diversity.

Question 7

A geneticist calculates a recombination frequency of $$12\%$$ between two genes. What does this indicate about their physical relationship?

Accepted Answer

The genes are relatively close together on the same chromosome.

Question 8

Which formula is used to calculate the expected genotype frequencies under Hardy-Weinberg equilibrium for a population with allele frequencies $$p$$ and $$q$$?

Accepted Answer

$$p^2$$ for homozygous dominant, $$2pq$$ for heterozygotes, $$q^2$$ for homozygous recessive

Question 9

In a pedigree analysis, which inheritance pattern is suggested if a trait appears in every generation and affects both males and females equally?

Accepted Answer

Autosomal dominant

Question 10

A researcher uses the chi-square test to compare observed and expected genetic ratios. Which formula should be used?

Accepted Answer

$$\$$chi^2$$ = \sum \frac{(O - E)^2$}{E}$$

Question 11

Which of the following best explains why inbreeding increases the risk of genetic disorders?

Accepted Answer

It increases homozygosity, making recessive alleles more likely to be expressed.

Question 12

Which process is responsible for the exchange of genetic material between non-sister chromatids during meiosis?

Accepted Answer

Crossing over

Question 13

A bacterial cell acquires new genetic material by uptake of naked DNA from its environment. What is this process called?

Accepted Answer

Transformation

Question 14

Which of the following is a function of plasmids in bacteria?

Accepted Answer

Carrying genes for antibiotic resistance

Question 15

A mutation at the DNA level results in a change from $$GAA to$$ $$GAG in $$the coding sequence. What is the likely outcome?

Accepted Answer

No change in the amino acid sequence (silent mutation)

Question 16

Which equation would you use to predict the frequency of heterozygotes in a population under Hardy-Weinberg equilibrium?

Accepted Answer

$$2pq$$

Question 17

Which genetic exchange mechanism in bacteria requires direct cell-to-cell contact and involves the F-factor?

Accepted Answer

Conjugation

Question 18

A population is not in Hardy-Weinberg equilibrium. Which of the following could be a reason?

Accepted Answer

Natural selection is acting on the population

Question 19

Which of the following best describes balancing selection?

Accepted Answer

Selection that maintains multiple alleles in a population

Question 20

In genetic mapping using conjugation experiments, what does a shorter time interval between gene transfer events indicate?

Accepted Answer

The genes are located closer together on the chromosome.

Comprehensive Study Guide: Genetics Exam II

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