Question 1

Which of the following best explains why Mendel chose the garden pea as his model organism for genetic experiments?

Accepted Answer

Peas produce large numbers of seeds, have a short generation time, and allow controlled matings.

Question 2

Mendel’s principle of segregation states that:

Accepted Answer

Two members of each gene pair segregate into different gametes during egg and sperm formation.

Question 3

In a dihybrid cross between two heterozygous pea plants (RrYy × RrYy), what is the expected phenotypic ratio of the offspring if the genes assort independently?

Accepted Answer

$$9:3:3:1$$

Question 4

A testcross is used to determine the genotype of a parent with a dominant phenotype. Which cross would you perform?

Accepted Answer

Cross the dominant phenotype parent with a homozygous recessive parent.

Question 5

Which of the following best describes the principle of independent assortment?

Accepted Answer

Alleles of different genes are transmitted independently of one another during meiosis.

Question 6

If two genes are located close together on the same chromosome, which of the following is most likely?

Accepted Answer

They will be inherited together more often than not (genetic linkage).

Question 7

The frequency of recombinant offspring can be used to estimate:

Accepted Answer

The relative distance between genes on a chromosome.

Question 8

Which of the following is an example of codominance in humans?

Accepted Answer

A person with type AB blood expressing both A and B antigens.

Question 9

In incomplete dominance, the heterozygote has which type of phenotype?

Accepted Answer

A phenotype intermediate between the two homozygotes.

Question 10

A plant with red flowers (RR) is crossed with a plant with white flowers (rr). If the offspring all have pink flowers, what type of inheritance is this?

Accepted Answer

Incomplete dominance

Question 11

Which of the following statements about quantitative traits is correct?

Accepted Answer

They result from the combined effect of many genes and often show a bell-shaped distribution.

Question 12

A pedigree shows a trait that appears in every generation and affects both males and females equally. What is the most likely mode of inheritance?

Accepted Answer

Autosomal dominant

Question 13

Which of the following best describes the inheritance pattern of red-green color blindness in humans?

Accepted Answer

X-linked recessive

Question 14

If a male with an X-linked recessive disorder has children with a female who is a carrier, what is the probability that a son will be affected?

Accepted Answer

$$0.25$$

Question 15

Which of the following is true regarding the ABO blood group system in humans?

Accepted Answer

The IA and IB alleles are codominant, and both are dominant over the i allele.

Question 16

A genetic map is constructed by:

Accepted Answer

Analyzing the frequency of recombination between genes.

Question 17

Which scenario best illustrates the effect of environment on phenotype?

Accepted Answer

Identical twins raised in different environments show differences in height and weight.

Question 18

If a trait is controlled by multiple genes and shows continuous variation, it is best described as:

Accepted Answer

A quantitative trait

Question 19

Which of the following is a correct statement about gene linkage and crossing over?

Accepted Answer

The farther apart two genes are on a chromosome, the more likely they are to be separated by crossing over.

Question 20

A woman with genotype $$I^A I^i$$ and a man with genotype $$I^B I^i$$ have a child. What is the probability that the child will have blood type AB?

Accepted Answer

$$0.25$$

Mendel and the Gene: Foundations and Extensions of Mendelian Genetics

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