Question 1

Which of the following best describes the difference between a somatic cell and a gamete in humans?

Accepted Answer

A somatic cell is diploid (2n = 46) and a gamete is haploid (n = 23).

Question 2

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

Accepted Answer

Crossing over occurs during Prophase I and creates genetic variation among gametes.

Question 3

If a human cell undergoes meiosis, how many chromosomes will each resulting daughter cell contain?

Accepted Answer

Each daughter cell will contain 23 chromosomes.

Question 4

Which of the following events is unique to meiosis I and does NOT occur in mitosis?

Accepted Answer

Formation of tetrads and crossing over between homologous chromosomes.

Question 5

A diploid cell in a human has $$2n = 46$$ chromosomes. After meiosis II, how many chromosomes are present in each gamete?

Accepted Answer

$$n = 23$$

Question 6

Which mechanism is responsible for the shuffling of genes on different chromosomes during gamete formation?

Accepted Answer

Independent assortment

Question 7

What is the result of the Law of Segregation during Anaphase I of meiosis?

Accepted Answer

Each gamete receives only one allele of each gene from the parent.

Question 8

Which of the following best explains why siblings from the same parents are genetically different?

Accepted Answer

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

Question 9

In a human male, what are the possible sex chromosome combinations in sperm cells?

Accepted Answer

Either X or Y chromosome

Question 10

Which of the following is true regarding homologous chromosomes?

Accepted Answer

They carry genes for the same traits but may have different alleles.

Question 11

During which stage of meiosis do homologous chromosomes separate?

Accepted Answer

Anaphase I

Question 12

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

Accepted Answer

Four haploid daughter cells with unreplicated chromosomes

Question 13

A mutation in a gene results in a new allele. What is the significance of this event in a population?

Accepted Answer

It is the original source of genetic diversity.

Question 14

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

Accepted Answer

Replication of chromosomes during mitosis

Question 15

If a plant species has a diploid number of $$2n = 24$$, what is the chromosome number in its gametes?

Accepted Answer

$$n = 12$$

Question 16

Which statement correctly describes the difference between sister chromatids and homologous chromosomes?

Accepted Answer

Sister chromatids are identical copies joined at the centromere; homologous chromosomes are similar but may have different alleles.

Question 17

Why does meiosis require two rounds of cell division?

Accepted Answer

To reduce the chromosome number by half and separate both homologous chromosomes and sister chromatids.

Question 18

Which phase of meiosis is most similar to mitosis, and why?

Accepted Answer

Meiosis II, because sister chromatids separate just as in mitosis.

Question 19

How does random fertilization contribute to genetic diversity in humans?

Accepted Answer

Any sperm can fuse with any egg, resulting in over 70 trillion possible genetic combinations.

Question 20

Which of the following best explains why no chromosome replication occurs between meiosis I and meiosis II?

Accepted Answer

Chromosomes are already replicated before meiosis I begins.

Meiosis & Sexual Life Cycles (Chapter 13) – Study Notes

Study Guide - Practice Questions