Question 1

Gregor Mendel is known for his foundational work in genetics. Which of the following best describes the significance of Mendel's experiments with pea plants?

Accepted Answer

He demonstrated that traits are inherited in discrete units called genes.

Question 2

In Mendel's monohybrid cross between true-breeding yellow-seeded and green-seeded pea plants, what was the observed ratio of yellow-seeded to green-seeded plants in the F2 generation?

Accepted Answer

$3:1$

Question 3

Which principle states that two alleles for a gene separate during gamete formation, and each gamete receives only one allele?

Accepted Answer

Principle of segregation

Question 4

A pea plant with genotype $Yy$ (Y = yellow, y = green) is self-fertilized. What is the probability that an offspring will have green seeds?

Accepted Answer

$0.25$

Question 5

Which event occurs during anaphase I of meiosis but not during mitosis?

Accepted Answer

Homologous chromosomes separate from each other

Question 6

In a dihybrid cross between pea plants with genotypes $RrYy$ (R = round, r = wrinkled; Y = yellow, y = green), what is the expected phenotypic ratio in the F2 generation?

Accepted Answer

$9:3:3:1$

Question 7

Which of the following best describes incomplete dominance?

Accepted Answer

The heterozygote phenotype is intermediate between the two homozygotes.

Question 8

A man and a woman are both heterozygous for the autosomal recessive allele causing phenylketonuria (PKU). What is the probability that their child will have the normal phenotype?

Accepted Answer

$0.75$

Question 9

Which of the following is an example of a pleiotropic gene?

Accepted Answer

A gene that affects both hemoglobin function and malaria resistance

Question 10

In human blood groups, which genotype(s) result in the AB phenotype?

Accepted Answer

$I^A I^B$

Question 11

A polydactylous man (dominant trait) marries a normal woman. What proportion of their children would be expected to be polydactylous if the man is heterozygous?

Accepted Answer

$0.5$

Question 12

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

Accepted Answer

Alleles of different genes segregate independently into gametes.

Question 13

In Labrador Retrievers, black fur (B) is dominant over brown (b), and normal vision (N) is dominant over blindness (n). If a brown, blind female ($bbnn$) mates with a black, sighted male and they have a black, blind puppy, what was the genotype of the male?

Accepted Answer

$BbNn$

Question 14

Which of the following is true about autosomal recessive genetic diseases?

Accepted Answer

They can skip generations.

Question 15

Familial hypercholesterolemia is an example of which type of inheritance?

Accepted Answer

Autosomal co-dominant (incomplete dominance)

Question 16

Which stage of meiosis is the first when haploid cells are formed?

Accepted Answer

Telophase I

Question 17

Which of the following is NOT a feature of Mendel's experimental design with pea plants?

Accepted Answer

Blending inheritance

Question 18

Which genotype would result in a person with type O blood?

Accepted Answer

$ii$

Question 19

Which of the following best describes a homozygous individual?

Accepted Answer

An individual with two identical alleles for a gene

Question 20

Which of the following is a real-world example of a co-dominant trait in humans?

Accepted Answer

ABO blood group

Mendelian Genetics: Principles, Experiments, and Applications

Study Guide - Practice Questions

Study Guide - Flashcards