Question 1

Which of the following best explains why Mendel's experiments with pea plants were more successful than previous studies of heredity?

Accepted Answer

He used a quantitative approach, controlled matings, and selected characters with two distinct forms.

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 white flowers? (Assume P = purple, p = white)

Accepted Answer

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

Question 3

Which of the following statements about alleles is CORRECT according to Mendel's model?

Accepted Answer

An organism inherits two alleles for each gene, one from each parent.

Question 4

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

Accepted Answer

PP

Question 5

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

Accepted Answer

Alleles for different genes segregate independently if they are on different chromosomes.

Question 6

In a dihybrid cross between two heterozygous pea plants (YyRr × YyRr), what is the probability of obtaining an offspring with genotype yyrr?

Accepted Answer

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

Question 7

A woman is a carrier for cystic fibrosis (genotype Nn, where n is the disease allele) and her partner is also a carrier. What is the probability that their first child will be a carrier?

Accepted Answer

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

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 of BbEe × BbEe?

Accepted Answer

9 black : 3 chocolate : 4 yellow

Question 10

A couple, both with a brother who died from a recessively inherited disease, want to know the probability that their child will have the disease. If each has a $$\frac{2}{3}$$ chance of being a carrier, what is the probability their child will be affected?

Accepted Answer

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

Question 11

Which of the following best illustrates incomplete dominance?

Accepted Answer

A cross between red and white snapdragons produces pink flowers.

Question 12

Which statement about the relationship between genotype and phenotype is correct?

Accepted Answer

Organisms with genotype PP and Pp have the same phenotype but different genotypes.

Question 13

Which of the following is true about dominant alleles?

Accepted Answer

Dominant alleles are not necessarily more frequent than recessive alleles.

Question 14

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

Accepted Answer

A or B

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 genetic counselor is working with a couple where both are carriers for sickle-cell disease. What is the probability that their child will be homozygous normal?

Accepted Answer

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

Question 17

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

Accepted Answer

Heart disease

Question 18

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

Accepted Answer

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

Question 19

Which of the following statements about Huntington’s disease is correct?

Accepted Answer

It is a dominant disorder with late onset symptoms.

Question 20

Which of the following best describes the use of the multiplication rule in genetics?

Accepted Answer

It is used to calculate the probability that two or more independent events will occur together.

Mendelian Genetics: Principles, Patterns, and Human Applications

Study Guide - Practice Questions

Study Guide - Flashcards