Question 1

Which of the following best explains why Mendel chose pea plants for his experiments on inheritance?

Accepted Answer

Pea plants have distinct, easily observable traits and allow controlled mating.

Question 2

A true-breeding purple-flowered pea plant (PP) is crossed with a true-breeding white-flowered pea plant (pp). What is the expected genotype and phenotype of the F₁ generation?

Accepted Answer

Genotype: Pp; Phenotype: all purple flowers

Question 3

Which of the following statements about Mendel’s law of segregation is correct?

Accepted Answer

It states that two alleles for a heritable character separate during gamete formation.

Question 4

In a monohybrid cross between two heterozygous pea plants (Pp × Pp), what is the probability that an offspring will be homozygous recessive?

Accepted Answer

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

Question 5

A plant with genotype Pp is crossed with a plant with genotype pp. What is the probability that an offspring will have the dominant phenotype?

Accepted Answer

$$\frac{1}{2}$$

Question 6

Which of the following best describes the difference between genotype and phenotype?

Accepted Answer

Genotype refers to the genetic makeup, while phenotype refers to the observable traits.

Question 7

A testcross is performed between a pea plant with an unknown genotype showing the dominant phenotype and a homozygous recessive plant. If all offspring display the dominant phenotype, what is the genotype of the unknown parent?

Accepted Answer

Homozygous dominant

Question 8

In a dihybrid cross between two heterozygous individuals (YyRr × YyRr), what is the expected phenotypic ratio in the F₂ generation according to Mendel’s law of independent assortment?

Accepted Answer

9:3:3:1

Question 9

Which scenario is an example of incomplete dominance?

Accepted Answer

A cross between red and white flowers produces pink flowers.

Question 10

A woman with type AB blood and a man with type O blood have a child. What are the possible blood types for their child?

Accepted Answer

Type A or Type B

Question 11

Which of the following best illustrates pleiotropy?

Accepted Answer

A single gene affects multiple traits, such as sickle-cell disease causing anemia, pain, and organ damage.

Question 12

In Labrador retrievers, coat color is determined by two genes. If a black lab (BbEe) is crossed with another black lab (BbEe), what is the expected ratio of black:chocolate:yellow offspring?

Accepted Answer

9:3:4

Question 13

Which of the following is an example of polygenic inheritance?

Accepted Answer

Height in humans

Question 14

A couple, both carriers for cystic fibrosis (a recessive disorder), have a child. What is the probability that their child will have cystic fibrosis?

Accepted Answer

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

Question 15

Which of the following statements about dominant alleles is correct?

Accepted Answer

Dominant alleles are not necessarily more common than recessive alleles.

Question 16

A man with Huntington’s disease (a dominant disorder) has a child with a woman who does not have the disease. If the man is heterozygous, what is the probability that their child will inherit the disease?

Accepted Answer

$$\frac{1}{2}$$

Question 17

Which of the following best describes the evolutionary advantage of the sickle-cell allele in certain populations?

Accepted Answer

Heterozygotes are less susceptible to malaria.

Question 18

Which of the following is an example of a multifactorial trait?

Accepted Answer

Skin pigmentation influenced by both genes and sunlight exposure

Question 19

If two individuals with the genotype AaBbCc (where each gene shows independent assortment and complete dominance) mate, what is the probability that their child will be homozygous recessive for all three genes?

Accepted Answer

$$\frac{1}{64}$$

Question 20

Which of the following best explains why consanguineous matings increase the risk of recessive genetic disorders?

Accepted Answer

They increase the chance that both parents carry the same rare allele.

Mendelian Genetics: Principles, Extensions, and Human Applications

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