Question 1

Which of the following best describes Mendel’s law of segregation?

Accepted Answer

Two alleles for a heritable character separate during gamete formation and end up in different gametes.

Question 2

A pea plant with genotype $$Pp is $$self-pollinated. What is the expected phenotypic ratio of purple to white flowers in the F2 generation?

Accepted Answer

$$3:1$$

Question 3

In a testcross between a purple-flowered pea plant of unknown genotype and a white-flowered plant, half the offspring have purple flowers and half have white flowers. What is the genotype of the purple-flowered parent?

Accepted Answer

Pp

Question 4

Which of the following is an example of incomplete dominance?

Accepted Answer

A cross between red-flowered and white-flowered snapdragons produces pink-flowered offspring.

Question 5

A man with blood type AB ($$I^A I^B) $$and a woman with blood type O ($$ii) $$have children. What are the possible blood types of their children?

Accepted Answer

A and B

Question 6

Which genetic phenomenon explains why cystic fibrosis affects the lungs, pancreas, and other organs?

Accepted Answer

Pleiotropy

Question 7

In Labrador retrievers, coat color is determined by two genes. One gene determines pigment color (B = black, b = brown), and another gene determines whether pigment is deposited (E = pigment, e = no pigment). What is the expected phenotypic ratio in the offspring of two dihybrid dogs ($$BbEe 	imes BbEe$$)?

Accepted Answer

$$9:3:4$$

Question 8

Which of the following best describes polygenic inheritance?

Accepted Answer

A single phenotypic character is affected by two or more genes, often resulting in continuous variation.

Question 9

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 their child will have albinism?

Accepted Answer

$$1/4$$

Question 10

Which of the following statements about dominant and recessive alleles is correct?

Accepted Answer

A dominant allele determines the phenotype in a heterozygote, while a recessive allele has no noticeable effect.

Question 11

If a genetic disorder is caused by a dominant allele, what is the probability that a child will inherit the disorder if one parent is heterozygous for the disorder and the other is homozygous normal?

Accepted Answer

$$1/2$$

Question 12

Which of the following scenarios illustrates codominance?

Accepted Answer

A cross between red and white cows produces roan cows with both red and white hairs.

Question 13

Which of the following is NOT a reason why humans are poor subjects for Mendelian genetic research?

Accepted Answer

Human genes do not follow Mendelian inheritance patterns.

Question 14

A plant with genotype $$AaBb is $$crossed with another plant with genotype $$AaBb. If $$the genes assort independently, what is the probability of obtaining an offspring with genotype $$aabb$$?

Accepted Answer

$$1/16$$

Question 15

Which of the following best explains why the F2 generation in Mendel’s monohybrid cross showed a 3:1 phenotypic ratio?

Accepted Answer

The two alleles segregated during gamete formation, resulting in three combinations with the dominant phenotype and one with the recessive.

Question 16

Which of the following is an example of a character with multiple alleles in humans?

Accepted Answer

ABO blood group

Question 17

A genetic counselor is working with a couple, both of whom are carriers for cystic fibrosis. What is the probability that their first child will be a carrier but not affected by the disease?

Accepted Answer

$$1/2$$

Question 18

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

Accepted Answer

Each pair of alleles segregates independently of other pairs during gamete formation.

Question 19

Which of the following is a real-world example of epistasis?

Accepted Answer

The coat color in Labrador retrievers, where one gene affects pigment color and another gene affects pigment deposition.

Mendelian Genetics and the Gene Idea: Patterns and Principles of Inheritance

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