Question 1

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

Accepted Answer

The 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 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 3

In a dihybrid cross between two heterozygous individuals (AaBb x AaBb), what is the probability that an offspring will be homozygous recessive for both traits?

Accepted Answer

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

Question 4

Which scenario illustrates the concept of pleiotropy?

Accepted Answer

A single gene affects multiple symptoms in sickle-cell disease.

Question 5

If a mystery plant with purple flowers is testcrossed with a homozygous recessive plant and some offspring have white flowers, what is the genotype of the mystery plant?

Accepted Answer

Heterozygous (Pp)

Question 6

Which of the following best explains why skin pigmentation in humans shows a wide range of variation?

Accepted Answer

Polygenic inheritance

Question 7

In Labrador retrievers, one gene determines pigment color (B for black, b for brown), and another gene (E for color, e for no color) determines whether pigment is deposited. What is the genotype of a yellow Labrador?

Accepted Answer

Any combination with ee (e.g., Bbee, bbee)

Question 8

A couple, both carriers for albinism (Aa), have a child. What is the probability that their child will have albinism?

Accepted Answer

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

Question 9

Which of the following statements about alleles is correct?

Accepted Answer

Alleles are alternative versions of a gene located at the same locus on homologous chromosomes.

Question 10

A monohybrid cross is performed between two heterozygous individuals (Aa x Aa). What is the expected genotypic ratio among the offspring?

Accepted Answer

1 AA : 2 Aa : 1 aa

Question 11

Which rule would you use to calculate the probability that a child will inherit both a recessive allele for albinism and a recessive allele for cystic fibrosis, assuming the genes are on different chromosomes?

Accepted Answer

Multiplication rule

Question 12

Which of the following is an example of codominance?

Accepted Answer

Both alleles are expressed in the phenotype, such as AB blood type in humans.

Question 13

In a pedigree, which individuals are considered carriers for a recessive disorder?

Accepted Answer

Heterozygous individuals who carry the recessive allele but are phenotypically normal.

Question 14

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

Accepted Answer

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

Question 15

A plant with genotype PP (homozygous dominant) is crossed with a plant with genotype pp (homozygous recessive). What will be the phenotype of all the F1 offspring?

Accepted Answer

All will have the dominant phenotype.

Question 16

Which of the following is NOT true about homozygotes?

Accepted Answer

They have two different alleles for a gene.

Question 17

A child is born with a recessive disorder, but both parents are phenotypically normal. What is the most likely explanation?

Accepted Answer

Both parents are carriers (heterozygous) for the disorder.

Question 18

Which of the following best describes incomplete dominance?

Accepted Answer

The phenotype of the heterozygote is intermediate between the phenotypes of the two parental varieties.

Question 19

If the probability of inheriting a recessive allele from one parent is $$\frac{1}{2}$$, and from the other parent is $$\frac{1}{2}$$, what is the probability that a child will inherit both recessive alleles?

Accepted Answer

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

Question 20

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

Accepted Answer

In Labrador retrievers, the E gene determines whether pigment is deposited, affecting the expression of the B gene for pigment color.

Mendelian Genetics: Principles and Applications

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