Question 1

Which of the following best describes the ploidy of human gametes?

Accepted Answer

Haploid (n)

Question 2

If a human cell contains 46 chromosomes, how many chromosomes will each gamete have after meiosis?

Accepted Answer

23

Question 3

Which event during meiosis is primarily responsible for genetic recombination?

Accepted Answer

Crossing over between nonsister chromatids during prophase I

Question 4

A karyotype of a human cell shows 47 chromosomes, including three copies of chromosome 21. What is this condition called?

Accepted Answer

Aneuploidy (specifically trisomy 21)

Question 5

During which phase of meiosis do homologous chromosomes separate?

Accepted Answer

Anaphase I

Question 6

Which formula correctly represents the chromosome number after meiosis in a diploid organism with $$2n = 6$$?

Accepted Answer

$$n = 3$$

Question 7

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

Accepted Answer

To reduce chromosome number by half and generate genetic diversity

Question 8

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

Accepted Answer

Mitosis produces two diploid cells, meiosis produces four haploid cells

Question 9

Which process is responsible for the random alignment of homologous chromosomes during meiosis, contributing to genetic variation?

Accepted Answer

Independent assortment

Question 10

A cell undergoes nondisjunction during meiosis I. What is the most likely outcome for the gametes produced?

Accepted Answer

Half the gametes will have an extra chromosome, and half will have one less

Question 11

Which term describes the physical location where crossing over occurs between homologous chromosomes?

Accepted Answer

Chiasma

Question 12

In the sexual life cycle of animals, which event restores the diploid chromosome number?

Accepted Answer

Fertilization

Question 13

Which of the following is NOT a source of genetic variation in meiosis?

Accepted Answer

DNA replication

Question 14

A cell with $$2n = 8$$ chromosomes undergoes meiosis. How many chromatids are present after DNA replication but before meiosis I begins?

Accepted Answer

$$16$$

Question 15

Which of the following best describes homologous chromosomes?

Accepted Answer

They carry genes controlling the same inherited characters but may have different alleles

Question 16

Which process in prokaryotes increases genetic variability without sexual reproduction?

Accepted Answer

Horizontal gene transfer

Question 17

During oogenesis, what is the fate of most of the cytoplasm?

Accepted Answer

It is retained in the ovum, while polar bodies receive little cytoplasm

Question 18

Which equation represents the relationship between chromosome number and ploidy in humans?

Accepted Answer

$$2n = 46$$

Question 19

Which stage of meiosis is characterized by the formation of tetrads and crossing over?

Accepted Answer

Prophase I

Question 20

A zygote is formed by the fusion of two gametes. If one gamete has an extra chromosome due to nondisjunction, what is the likely result?

Accepted Answer

The zygote will have an abnormal chromosome number, leading to aneuploidy

Meiosis: Mechanisms, Chromosome Behavior, and Genetic Variation

Study Guide - Practice Questions