Question 1

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

Accepted Answer

Pea plants have many distinct varieties, short generation times, and their mating can be controlled.

Question 2

A pea plant with genotype Pp is crossed with another plant of genotype pp. What is the probability that an offspring will have purple flowers, given that purple is dominant to white?

Accepted Answer

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

Question 3

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

Accepted Answer

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

Question 4

A testcross is performed between a pea plant with purple flowers of unknown genotype and a white-flowered plant. If all offspring have purple flowers, what is the genotype of the purple-flowered parent?

Accepted Answer

Homozygous dominant

Question 5

In a dihybrid cross between two heterozygous individuals (AaBb × AaBb), what is the probability of obtaining an offspring with the genotype aabb?

Accepted Answer

$$\frac{1}{16}$$

Question 6

Which of the following best describes the difference between incomplete dominance and codominance?

Accepted Answer

Incomplete dominance results in a phenotype that is a blend of the two parental traits, while codominance results in both parental traits being fully and separately expressed.

Question 7

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

Accepted Answer

Type A or Type B

Question 8

Which of the following is an example of pleiotropy?

Accepted Answer

A gene that affects multiple symptoms in cystic fibrosis

Question 9

In Labrador retrievers, coat color is determined by two genes: one for pigment color (B = black, b = brown) and one for pigment deposition (E = color, e = no color). What is the expected phenotypic ratio in the F2 generation from a cross between two BbEe dogs?

Accepted Answer

9 black : 3 chocolate : 4 yellow

Question 10

A couple, both of whom had a sibling with a recessively inherited disease, want to know the probability that their child will have the disease. If neither parent nor their parents are affected, what is the probability their child will have the disease?

Accepted Answer

$$\frac{1}{9}$$

Question 11

Which of the following best explains why dominant alleles are not necessarily more common than recessive alleles in a population?

Accepted Answer

Dominant alleles can be rare due to factors such as negative selection or recent mutation, as seen in polydactyly.

Question 12

A genetic counselor is working with a family where both parents are carriers for cystic fibrosis, a recessive disorder. What is the probability that their first two children will both be unaffected by the disease?

Accepted Answer

$$\frac{9}{16}$$

Question 13

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

Accepted Answer

Heart disease

Question 14

If a heterozygous individual for sickle-cell disease (Ss) is crossed with another heterozygote (Ss), what is the probability that their child will be a carrier (heterozygous) for the disease?

Accepted Answer

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

Question 15

Which of the following best describes polygenic inheritance?

Accepted Answer

Multiple genes independently affect a single trait, resulting in continuous variation.

Question 16

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

Accepted Answer

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

Question 17

Which of the following scenarios illustrates the law of independent assortment?

Accepted Answer

A gene for flower color segregates independently from a gene for seed shape during gamete formation.

Question 18

A woman who is a carrier for albinism (Aa) and a man who is also a carrier (Aa) have a child. What is the probability that the child will have normal pigmentation?

Accepted Answer

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

Question 19

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

Accepted Answer

Close relatives are more likely to carry the same rare recessive alleles.

Question 20

Which of the following statements about the relationship between genotype and phenotype is correct?

Accepted Answer

Two organisms with the same phenotype can have different genotypes.

Mendelian Genetics: Principles, Patterns, and Human Applications

Study Guide - Practice Questions

Study Guide - Flashcards