Question 1

Which statement best explains the concept of genetic continuity in eukaryotic cells?

Accepted Answer

Genetic continuity is maintained because all cells arise from pre-existing cells through cell division.

Question 2

In humans, what is the haploid number ($$n) of $$chromosomes found in gametes?

Accepted Answer

$$n = 23$$

Question 3

Which of the following best describes homologous chromosomes?

Accepted Answer

Chromosomes with the same genes in the same position from the same species, but possibly different alleles.

Question 4

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

Accepted Answer

Production of haploid gametes that can fuse during fertilization to restore diploid chromosome number.

Question 5

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

Accepted Answer

Prophase I; it increases genetic variation among gametes.

Question 6

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

Accepted Answer

$$n = 4$$

Question 7

Which of the following is a direct result of crossing over during meiosis?

Accepted Answer

Each sister chromatid becomes genetically different from the others.

Question 8

A mutation in the CFTR gene affects the CFTR gated channel. What is the likely cellular consequence?

Accepted Answer

Impaired chloride ion transport across the cell membrane.

Question 9

Which term describes chromosomes that differ in males and females?

Accepted Answer

Sex chromosomes

Question 10

What is the ploidy level of a zygote formed after fertilization in humans?

Accepted Answer

Diploid ($$2n)$$

Question 11

Which process restores the diploid chromosome number in sexually reproducing organisms?

Accepted Answer

Fertilization

Question 12

Which of the following best describes an allele?

Accepted Answer

A different version of the same gene found at the same locus on homologous chromosomes.

Question 13

During meiosis, when are homologous chromosomes separated into different daughter cells?

Accepted Answer

Meiosis I

Question 14

Which of the following is NOT a source of genetic variation in sexually reproducing organisms?

Accepted Answer

DNA replication during S phase

Question 15

A plant species has a diploid number of $$2n = 18. $$After meiosis, what is the chromosome number in its pollen cells?

Accepted Answer

$$n = 9$$

Question 16

Which event occurs during the S phase of interphase prior to meiosis?

Accepted Answer

Each chromosome replicates to form sister chromatids.

Question 17

Which of the following best describes the difference between autosomes and sex chromosomes?

Accepted Answer

Autosomes do not differ between males and females, while sex chromosomes do.

Question 18

What is the result of meiosis II?

Accepted Answer

Separation of sister chromatids into genetically different daughter cells.

Question 19

Which of the following scenarios would most likely result in a genetic disorder due to abnormal chromosome number?

Accepted Answer

Failure of homologous chromosomes to separate during meiosis I.

Question 20

A dog’s somatic cells are diploid ($$2n). $$During its life cycle, when does the chromosome number reduce to haploid ($$n$$)?

Accepted Answer

During meiosis, when gametes are formed.

Genetic Continuity and Meiosis: Chromosome Structure, Alleles, and Sexual Reproduction

Study Guide - Practice Questions