Question 1

Which of the following best describes Mendel’s principle of independent assortment?

Accepted Answer

Unit factors (genes) assort independently during gamete formation, so the inheritance of one trait does not affect the inheritance of another trait.

Question 2

In a dihybrid cross between two heterozygous pea plants (YyRr x YyRr), what is the expected phenotypic ratio in the F2 generation?

Accepted Answer

$$9:3:3:1$$

Question 3

A true-breeding tall pea plant is crossed with a true-breeding dwarf pea plant. All F1 offspring are tall. What does this indicate about the alleles for plant height?

Accepted Answer

The allele for tallness is dominant over the allele for dwarfness.

Question 4

If a plant with genotype Yy is self-fertilized, what proportion of the offspring will be homozygous recessive?

Accepted Answer

$$\frac{1}{4}$$

Question 5

Which of the following statements about Mendel’s experimental approach is FALSE?

Accepted Answer

He used pea plants because they were difficult to grow and had many traits with continuous variation.

Question 6

How many different types of gametes can a human produce due to independent assortment, given $$n = 23$$ pairs of chromosomes?

Accepted Answer

$$2^{23}$$

Question 7

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 8

Which of the following is NOT a criterion for homologous chromosomes?

Accepted Answer

They always carry identical alleles for every gene.

Question 9

What is the probability that two heterozygous parents (Yy) will produce an offspring with the dominant phenotype?

Accepted Answer

$$\frac{3}{4}$$

Question 10

Which of the following best explains why Mendel’s work was not appreciated during his lifetime?

Accepted Answer

The scientific community at the time favored the theory of blending inheritance.

Question 11

A man and woman are both heterozygous for a recessive genetic disorder. What is the probability that their child will be affected by the disorder?

Accepted Answer

$$\frac{1}{4}$$

Question 12

Which of the following is a correct statement about the chromosomal theory of inheritance?

Accepted Answer

Genes are located on chromosomes, and their behavior during meiosis explains Mendel’s principles.

Question 13

In a monohybrid cross, what is the expected genotypic ratio in the F2 generation?

Accepted Answer

$$1:2:1$$

Question 14

Which of the following best describes a Punnett square?

Accepted Answer

A diagram that predicts the genotypic and phenotypic outcomes of a genetic cross.

Question 15

If a plant with genotype YyRr is crossed with a plant with genotype yyrr, what proportion of the offspring will have yellow, round seeds? (Assume Y = yellow, y = green, R = round, r = wrinkled)

Accepted Answer

$$\frac{1}{4}$$

Question 16

Which of the following is an example of a phenotype?

Accepted Answer

Round seeds

Question 17

What is the function of a test cross in genetics?

Accepted Answer

To determine the genotype of an individual with a dominant phenotype by crossing it with a homozygous recessive individual.

Question 18

Which of the following best describes the concept of segregation as proposed by Mendel?

Accepted Answer

Paired unit factors separate randomly into gametes during meiosis.

Question 19

A pedigree analysis reveals that a trait skips generations and appears only in siblings, not in parents. What is the most likely mode of inheritance?

Accepted Answer

Autosomal recessive

Question 20

Which of the following is a direct result of independent assortment during meiosis?

Accepted Answer

Extensive genetic variation among offspring

Mendelian Genetics: Principles and Applications

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