Q: Which equation would you use to calculate the probability of two independent events both occurring?

$$P(A \text{ and } B) = P(A) \times P(B)$$

Question 1

Which of the following best describes incomplete dominance in genetic inheritance?

Accepted Answer

The heterozygote expresses a phenotype that is intermediate between the two homozygotes.

Question 2

In a monohybrid cross involving a recessive lethal allele, what is the expected phenotypic ratio among the surviving offspring?

Accepted Answer

2:1

Question 3

A woman with blood type AB and a man with blood type O have children. Which blood types are possible for their offspring?

Accepted Answer

A and B

Question 4

Which equation would you use to calculate the probability of two independent events both occurring?

Accepted Answer

$$P(A 	ext{ and } B) = P(A) 	imes P(B)$$

Question 5

Which of the following best describes pleiotropy?

Accepted Answer

A single gene influences multiple, seemingly unrelated phenotypic traits.

Question 6

In a dihybrid cross involving two genes with epistatic interaction, which modified phenotypic ratio might you observe instead of the classic 9:3:3:1 ratio?

Accepted Answer

9:7

Question 7

Which of the following statements about sex-linked traits is correct?

Accepted Answer

Males are more likely to express recessive X-linked traits because they are hemizygous for the X chromosome.

Question 8

How many pairs of chromosomes are found in a wild-type human karyotype?

Accepted Answer

23

Question 9

Which term describes the phenomenon where an individual has only one copy of a gene in a diploid organism, such as males for genes on the X chromosome?

Accepted Answer

Hemizygosity

Question 10

Which sex is heterogametic in humans, and what does this mean?

Accepted Answer

Males; they produce two types of gametes (X and Y).

Question 11

A trait shows 80% penetrance. If 100 individuals have the genotype, how many are expected to express the phenotype?

Accepted Answer

80

Question 12

Which of the following best describes expressivity?

Accepted Answer

The degree to which a genotype is expressed in an individual.

Question 13

Which scenario illustrates environmental influence on phenotypic expression?

Accepted Answer

A Himalayan rabbit develops darker fur on its ears and feet when raised in a cold environment.

Question 14

What is the purpose of a complementation test?

Accepted Answer

To determine whether mutations causing a similar phenotype are in the same gene or in different genes.

Question 15

Which of the following is true about mitochondrial inheritance?

Accepted Answer

Mitochondrial DNA is inherited exclusively from the mother.

Question 16

Which term describes the presence of more than one type of mitochondrial DNA within a cell?

Accepted Answer

Heteroplasmy

Question 17

Which of the following is a characteristic shared by both mitochondrial and chloroplast genomes, but not nuclear genomes?

Accepted Answer

They are typically inherited uniparentally.

Question 18

A dihybrid cross between two plants (AaBb x AaBb) yields a 9:3:4 phenotypic ratio. Which gene interaction is most likely responsible?

Accepted Answer

Recessive epistasis

Question 19

If two parents are both heterozygous for a recessive lethal allele (L), what is the expected genotypic ratio among their offspring?

Accepted Answer

$$1:2 (LL$$:Ll)

Question 20

Which of the following best explains why some genetic diseases caused by mitochondrial mutations can vary in severity among siblings?

Accepted Answer

Different proportions of mutant and normal mitochondria (heteroplasmy) are inherited by each sibling.

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