Question 1

Which of the following best describes Mendel’s Law of Segregation?

Accepted Answer

Each organism contains two alleles for each trait, and these alleles segregate during meiosis so that each gamete contains one allele.

Question 2

A pea plant with genotype $$Yy ($$yellow seeds) is crossed with another $$Yy$$ plant. What is the expected phenotypic ratio of yellow to green seeds in the offspring?

Accepted Answer

$$3:1$$

Question 3

Which scenario is an example of incomplete dominance?

Accepted Answer

A cross between red and white flowers produces pink flowers.

Question 4

In a dihybrid cross between two $$RrYy$$ pea plants, what is the expected phenotypic ratio for the offspring?

Accepted Answer

$$9:3:3:1$$

Question 5

Which of the following is true about sex-linked recessive disorders in humans?

Accepted Answer

Males are more likely to express X-linked recessive disorders because they have only one X chromosome.

Question 6

A man with genotype $$IAIB$$ and a woman with genotype $$ii$$ have a child. What is the probability that the child will have blood type A?

Accepted Answer

$$0.5$$

Question 7

Which of the following best explains the concept of pleiotropy?

Accepted Answer

One gene influences multiple phenotypic traits.

Question 8

If a true-breeding tall pea plant ($$TT) is $$crossed with a true-breeding short pea plant ($$tt$$), what will be the genotype of the F1 generation?

Accepted Answer

$$Tt$$

Question 9

Which of the following is an example of codominance?

Accepted Answer

A person with both $$IA$$ and $$IB$$ alleles expresses both A and B antigens in their blood.

Question 10

A woman who is a carrier for an X-linked recessive disorder ($$X^NX^n) $$and a man who does not have the disorder ($$X^NY) $$have a son. What is the probability that their son will have the disorder?

Accepted Answer

$$0.5$$

Question 11

Which of the following statements about linked genes is correct?

Accepted Answer

Linked genes are located close together on the same chromosome and tend to be inherited together.

Question 12

In polygenic inheritance, which of the following is most likely to be observed?

Accepted Answer

A continuous range of phenotypes, such as human height.

Question 13

If a heterozygous pea plant ($$Yy) is $$test-crossed with a homozygous recessive plant ($$yy$$), what is the expected ratio of yellow to green seeds in the offspring?

Accepted Answer

$$1:1$$

Question 14

Which of the following is a real-world example of a disease caused by pleiotropy?

Accepted Answer

Sickle-cell disease, which affects hemoglobin shape and causes anemia and organ damage.

Question 15

A male fruit fly has only one X chromosome. If he inherits a recessive allele for white eyes on the X chromosome, what will be his eye color?

Accepted Answer

White, because there is no dominant allele to mask the recessive allele.

Question 16

Which of the following best describes Mendel’s Law of Independent Assortment?

Accepted Answer

Alleles for different traits segregate independently during gamete formation.

Question 17

A pedigree shows a trait that appears mostly in males and skips generations. What is the most likely mode of inheritance?

Accepted Answer

X-linked recessive

Question 18

If two parents are both heterozygous for cystic fibrosis ($$Ff$$), what is the probability that their child will have cystic fibrosis?

Accepted Answer

$$0.25$$

Question 19

Which of the following is NOT a variation on Mendel’s laws?

Accepted Answer

Mitochondrial inheritance

Question 20

A geneticist uses crossover data to map genes on a chromosome. What does a low recombination frequency between two genes indicate?

Accepted Answer

The genes are close together on the chromosome.

Patterns of Inheritance: Mendelian Genetics and Its Variations

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