Question 1

Which of the following best describes the main difference between sexual and asexual reproduction in terms of genetic variation?

Accepted Answer

Sexual reproduction increases genetic variation among offspring due to mechanisms such as crossing over and independent assortment.

Question 2

In humans, how many chromosomes are present in a typical gamete, and what term describes this chromosome number?

Accepted Answer

23 chromosomes; haploid ($$n)$$

Question 3

Which of the following events during meiosis contributes most directly to the production of recombinant chromosomes?

Accepted Answer

Crossing over between non-sister chromatids during prophase I

Question 4

A human cell with 22 autosomes and an X chromosome is best described as:

Accepted Answer

A haploid gamete that could be either an egg or a sperm

Question 5

Which process restores the diploid chromosome number in the human life cycle?

Accepted Answer

Fertilization

Question 6

During which stage of meiosis do homologous chromosomes line up as pairs along the metaphase plate?

Accepted Answer

Metaphase I

Question 7

If a human zygote has 47 chromosomes, which of the following most likely occurred during gamete formation?

Accepted Answer

Nondisjunction occurred during meiosis, resulting in a gamete with an extra chromosome

Question 8

Which of the following best explains why the sperm determines the genetic sex of human offspring?

Accepted Answer

Sperm can carry either an X or a Y chromosome, while eggs only carry an X chromosome.

Question 9

Which of the following is a key difference between mitosis and meiosis in diploid cells?

Accepted Answer

Mitosis involves one cell division, while meiosis involves two consecutive cell divisions.

Question 10

A gene is located at a specific position on a chromosome. What is this position called?

Accepted Answer

Locus

Question 11

Which of the following mechanisms does NOT contribute to genetic variation in sexually reproducing organisms?

Accepted Answer

Replication of DNA during interphase

Question 12

If a cell with a diploid number of $$2n = 8$$ undergoes meiosis, how many chromosomes will each resulting gamete contain?

Accepted Answer

$$4$$

Question 13

Which of the following best describes homologous chromosomes?

Accepted Answer

They carry the same genes at the same loci, but may have different alleles.

Question 14

During which phase of meiosis does crossing over occur, and what is its significance?

Accepted Answer

Prophase I; it increases genetic variation among gametes

Question 15

A male patient’s karyotype shows 44 autosomes and XY sex chromosomes. How many chromosomes are present in his sperm after meiosis?

Accepted Answer

23

Question 16

Which of the following scenarios illustrates independent assortment?

Accepted Answer

Maternal and paternal chromosomes randomly aligning on the metaphase plate during metaphase I

Question 17

If a mutation occurs in a gene located on an autosome, which of the following is true?

Accepted Answer

The mutation can be inherited by either male or female offspring.

Question 18

Which of the following best explains why siblings from the same parents can look very different from each other?

Accepted Answer

Genetic variation arises from independent assortment, crossing over, and random fertilization.

Question 19

Which of the following is true regarding the chromosome number in human somatic cells versus gametes?

Accepted Answer

Somatic cells are diploid ($$2n$$), and gametes are haploid ($$n).$$

Question 20

Which of the following correctly matches the stage of meiosis with its key event?

Accepted Answer

Anaphase I: Homologous chromosomes separate

Study Guide: Meiosis, Sexual Reproduction, and Chromosomal Inheritance

Study Guide - Practice Questions