Question 1

Which process is responsible for reducing the chromosome number from diploid to haploid in sexually reproducing organisms?

Accepted Answer

Meiosis

Question 2

In humans, how many chromosomes are present in a haploid gamete?

Accepted Answer

$$n = 23$$

Question 3

Which event during meiosis is primarily responsible for genetic recombination?

Accepted Answer

Crossing over during prophase I

Question 4

A child inherits half of their chromosomes from each parent. Which biological process ensures this distribution?

Accepted Answer

Independent assortment during meiosis I

Question 5

What is the main difference between asexual and sexual reproduction in terms of genetic diversity?

Accepted Answer

Asexual reproduction produces genetically identical offspring; sexual reproduction produces genetically diverse offspring.

Question 6

During which phase of meiosis do homologous chromosomes separate?

Accepted Answer

Anaphase I

Question 7

If a human cell with a diploid number of $$2n = 46$$ undergoes meiosis, how many chromosomes will each resulting gamete contain?

Accepted Answer

$$23$$

Question 8

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

Accepted Answer

Random fertilization and independent assortment during meiosis

Question 9

What is the expected number of possible chromosome combinations in human gametes due to independent assortment alone?

Accepted Answer

$$2^{23}$$

Question 10

Which statement about crossing over is correct?

Accepted Answer

It occurs during prophase I of meiosis and increases genetic variation.

Question 11

A diploid organism has a total of $$2n = 8$$ chromosomes. After meiosis, how many chromosomes will each gamete have?

Accepted Answer

$$4$$

Question 12

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

Accepted Answer

DNA replication during S phase

Question 13

What is the role of synapsis during meiosis?

Accepted Answer

Pairing of homologous chromosomes to allow crossing over

Question 14

Which phase of meiosis is characterized by the alignment of homologous chromosomes at the metaphase plate?

Accepted Answer

Metaphase I

Question 15

Why is sexual reproduction considered advantageous for evolution?

Accepted Answer

It increases genetic variation, providing raw material for natural selection.

Question 16

Which of the following is a direct result of fertilization in humans?

Accepted Answer

Restoration of the diploid chromosome number

Question 17

During meiosis, what is the significance of the chiasmata?

Accepted Answer

They are sites where crossing over occurs between homologous chromosomes.

Question 18

Which of the following best describes the difference between mitosis and meiosis?

Accepted Answer

Mitosis produces two genetically identical diploid cells; meiosis produces four genetically diverse haploid cells.

Question 19

If a mutation occurs in a gene located on a sex chromosome, which type of cell division will ensure its transmission to offspring?

Accepted Answer

Meiosis

Question 20

Which equation correctly represents the restoration of chromosome number after fertilization in humans?

Accepted Answer

$$n + n = 2n$$

Sexual Life Cycles and Meiosis: Mechanisms and Evolutionary Significance

Study Guide - Practice Questions