Question 1

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

Accepted Answer

Two alleles for a gene separate during gamete formation, so each gamete receives only one allele.

Question 2

In a dihybrid cross between plants with genotypes YYRR and yyrr, what phenotypic ratio is expected in the F₂ generation if the genes assort independently?

Accepted Answer

$$9:3:3:1$$

Question 3

A plant with genotype Pp is self-fertilized. What is the probability that an offspring will have white flowers, assuming purple (P) is dominant to white (p)?

Accepted Answer

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

Question 4

Which experimental result provided the first solid evidence that genes are located on chromosomes?

Accepted Answer

Morgan's fruit fly crosses showing X-linked inheritance of eye color

Question 5

A male fruit fly with white eyes (XʳY) is crossed with a female with red eyes (XᴿXʳ). What proportion of their male offspring will have white eyes?

Accepted Answer

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

Question 6

Which statement about human sex chromosomes is correct?

Accepted Answer

The X chromosome contains many genes unrelated to sex determination.

Question 7

A woman who is a carrier for an X-linked recessive disorder and a man who is unaffected have a child. What is the probability that their son will be affected?

Accepted Answer

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

Question 8

Which of the following best explains why tortoiseshell cats are almost always female?

Accepted Answer

X-inactivation in females leads to mosaic expression of coat color alleles.

Question 9

If two genes are located close together on the same chromosome, which of the following is most likely?

Accepted Answer

They are linked and tend to be inherited together.

Question 10

A testcross between a dihybrid and a double recessive individual yields 1000 offspring: 800 parental type and 200 recombinant type. What is the recombination frequency between the two genes?

Accepted Answer

$$20\%$$

Question 11

Which chromosomal alteration is most likely to result in a genetic disorder due to the loss of essential genes?

Accepted Answer

Deletion

Question 12

A father with an X-linked dominant disorder and an unaffected mother have children. Which of the following is true about their offspring?

Accepted Answer

All daughters will be affected.

Question 13

Which of the following best describes the function of pseudoautosomal regions (PARs) on sex chromosomes?

Accepted Answer

They allow X and Y chromosomes to pair and recombine during meiosis.

Question 14

Which chromosomal alteration is associated with chronic myelogenous leukemia (CML)?

Accepted Answer

Translocation

Question 15

A woman with genotype XᴿXʳ (red eyes) and a man with genotype XʳY (white eyes) have children. What is the probability that a daughter will have white eyes?

Accepted Answer

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

Question 16

Which of the following is a real-world example of a disorder caused by a chromosomal deletion?

Accepted Answer

Cri du chat syndrome

Question 17

If a gene is located far from another gene on the same chromosome, what can be inferred about their recombination frequency?

Accepted Answer

It will be high because crossing over is more likely to occur between them.

Question 18

Which of the following best explains why X-inactivation is important in female mammals?

Accepted Answer

It balances the expression of X-linked genes between males and females.

Question 19

A chromosomal inversion occurs. Which of the following is a possible consequence?

Accepted Answer

Genes may not function properly if regulatory regions are disrupted.

Question 20

Which of the following statements about linked genes is correct?

Accepted Answer

Crossing over can separate linked genes, resulting in genetic recombination.

Chromosomal Basis of Inheritance: Mendelian Laws, Chromosome Theory, and Linkage

Guida di studio - Domande di pratica

Study guide - Flashcard