Question 1

Which of the following best explains why sexual reproduction typically results in greater genetic variation than asexual reproduction?

Accepted Answer

Sexual reproduction involves the uniting of genes from two parents, leading to new combinations of alleles.

Question 2

In humans, what is the chromosome number in a diploid somatic cell and a haploid gamete, respectively?

Accepted Answer

Diploid: 46, Haploid: 23

Question 3

Which event is unique to meiosis and does NOT occur in mitosis?

Accepted Answer

Homologous chromosomes synapse and crossing over occurs.

Question 4

During which phase of meiosis do homologous chromosomes separate, reducing the chromosome number by half?

Accepted Answer

Anaphase I

Question 5

If a human cell with 46 chromosomes undergoes meiosis, how many chromosomes will each resulting gamete contain?

Accepted Answer

$$23$$

Question 6

Which mechanism during meiosis is responsible for the exchange of genetic material between homologous chromosomes?

Accepted Answer

Crossing over at chiasmata

Question 7

How many genetically distinct gametes can be produced by independent assortment in a human, given $$n = 23$$?

Accepted Answer

$$2^{23}$$

Question 8

Which of the following statements about homologous chromosomes is correct?

Accepted Answer

They carry the same genes but may have different alleles.

Question 9

What is the primary purpose of meiosis in sexually reproducing organisms?

Accepted Answer

To reduce the chromosome number by half, forming haploid gametes.

Question 10

Which process restores the diploid chromosome number after meiosis?

Accepted Answer

Fertilization

Question 11

During which stage of meiosis do homologous chromosomes align on the metaphase plate?

Accepted Answer

Metaphase I

Question 12

Which of the following is NOT a mechanism that contributes to genetic variation in sexually reproducing organisms?

Accepted Answer

Replication of DNA without error

Question 13

A male human has a karyotype of 46 chromosomes. How many autosomes and sex chromosomes are present?

Accepted Answer

44 autosomes and 2 sex chromosomes (XY)

Question 14

Which statement correctly describes the difference between mitosis and meiosis?

Accepted Answer

Mitosis produces two identical diploid cells, meiosis produces four unique haploid cells.

Question 15

During crossing over, which chromatids exchange genetic material?

Accepted Answer

Nonsister chromatids of homologous chromosomes

Question 16

Which phase of meiosis is responsible for separating sister chromatids?

Accepted Answer

Anaphase II

Question 17

If a diploid cell contains 8 chromosomes, how many chromosomes will each gamete have after meiosis?

Accepted Answer

$$4$$

Question 18

Which of the following best describes the outcome of meiosis II?

Accepted Answer

Four haploid cells, each with one chromatid per chromosome

Question 19

Which of the following is true regarding the sex chromosomes in human males?

Accepted Answer

Males have one X and one Y chromosome and are haploid for the sex chromosomes.

Question 20

Which of the following best explains the role of fertilization in the human life cycle?

Accepted Answer

It restores the diploid chromosome number by combining two haploid gametes.

Meiosis and Sexual Lifestyles: Chromosome Number, Mechanisms, and Genetic Variation

Study Guide - Practice Questions