Quiz: Cell Division: Mitosis and Meiosis — 11 questions

1. What sequence of events defines the cell cycle?

A. Genetic-material exchange, cell migration, and tissue repair

B. Growth, protein breakdown, and fusion into a larger cell

C. Growth, genetic-material duplication, and distribution into daughter cells

D. Chromosome pairing, mutation formation, and cell specialization

Answer: (C)

Explanation

The cell cycle is the ordered process in which a mother cell grows, duplicates its genetic material, and distributes it into forming daughter cells. Chromosome pairing and cell specialization can occur in particular contexts but do not define the complete cycle.

2. What is the cell cycle?

A. A cycle that only occurs in germ cells during gamete formation.

B. The sequence of events by which a mother cell grows, duplicates its genetic material, and distributes it into daughter cells.

C. A process where cells die and are replaced by new cells.

D. The process of cell differentiation into specialized cell types.

Answer: (B)

Explanation

The cell cycle describes the series of events where a mother cell grows, duplicates its genetic material, and divides into daughter cells. The other options describe different cellular processes, not the overall cycle.

3. Which sequence correctly distinguishes interphase from phase M?

A. Interphase includes mitosis and cytokinesis, whereas phase M includes G1, S, and G2

B. Interphase includes G1 and mitosis, whereas phase M includes S, G2, and cytokinesis

C. Interphase includes G1, S, and G2, whereas phase M includes mitosis and cytokinesis

D. Interphase includes S and cytokinesis, whereas phase M includes G1, G2, and mitosis

Answer: (C)

Explanation

Interphase consists of G1, S, and G2, while phase M consists of mitosis and cytokinesis. The main confusion is assigning the growth and DNA-replication stages to phase M rather than to interphase.

4. In the context of the cell cycle, what does the term 'semi-conservative replication' specifically refer to?

A. It describes the duplication of the entire genome in a single replication event, resulting in two identical sets.

B. It means that the genetic material is divided equally between two daughter cells during mitosis.

C. It refers to the process where each chromosome is duplicated into two chromatids without changing the chromosome number.

D. It indicates that only one strand of the DNA double helix is replicated during the S phase.

Answer: (C)

Explanation

Semi-conservative replication means each chromosome is duplicated into two chromatids, but the chromosome number remains unchanged. The distractor suggesting genome duplication in a single event describes replication but not the semi-conservative mechanism.

5. A human cell completes mitosis. What chromosome and chromatid content does each resulting cell have?

A. 23 chromosomes, with one chromatid per chromosome

B. 46 chromosomes, with two chromatids per chromosome

C. 23 chromosomes, with two chromatids per chromosome

D. 46 chromosomes, with one chromatid per chromosome

Answer: (D)

Explanation

Mitosis in humans produces two cells, each containing 46 chromosomes with one chromatid per chromosome. The 23-chromosome outcome describes the products of meiosis rather than mitosis.

6. What is the primary purpose of mitotic phases and cytokinesis in the cell cycle?

A. To increase genetic diversity through crossing-over and random assortment

B. To reduce the chromosome number by half in germ cells

C. To prepare the cell for meiosis by pairing homologous chromosomes

D. To ensure accurate duplication and distribution of genetic material into daughter cells

Answer: (D)

Explanation

The main role of mitotic phases and cytokinesis is to accurately duplicate and evenly distribute genetic material into two genetically identical daughter cells. Crossing-over and random assortment are specific to meiosis, not mitosis.

7. Which statement correctly distinguishes homologous chromosomes from sister chromatids?

A. Homologous chromosomes are the two products of cytokinesis, whereas sister chromatids are chromosomes from different cells

B. Homologous chromosomes are paired chromosomes of one type, whereas sister chromatids are copies within one chromosome

C. Homologous chromosomes are copies within one chromosome, whereas sister chromatids are paired chromosomes of one type

D. Homologous chromosomes are duplicated DNA strands, whereas sister chromatids are unrelated chromosomes with similar genes

Answer: (B)

Explanation

Homologous chromosomes form a pair of chromosomes of the same type, while sister chromatids are the two copies produced when one chromosome replicates. Confusing these terms reverses a chromosome pair with the copies contained within one replicated chromosome.

8. During which phase of meiosis do homologous chromosomes pair up into bivalents before the subsequent divisions?

A. Prophase I

B. Telophase I

C. Metaphase I

D. Anaphase I

Answer: (A)

Explanation

Homologous chromosomes pair into bivalents during prophase I of meiosis, which is essential for crossing-over and genetic recombination. In contrast, metaphase I aligns these pairs at the metaphase plate, but pairing occurs earlier in prophase I.

9. How does the process of genetic mixing in meiosis differ from that in mitosis?

A. Mitosis involves homologous chromosome separation, whereas meiosis separates sister chromatids.

B. Meiosis only occurs in somatic cells, unlike mitosis which occurs in germinal cells.

C. Meiosis results in identical genetic material in daughter cells, while mitosis involves crossing-over and genetic variation.

D. Meiosis involves crossing-over and random assortment, increasing genetic diversity, whereas mitosis produces genetically identical daughter cells without such mixing.

Answer: (D)

Explanation

Meiosis includes crossing-over and the random distribution of homologous chromosomes, both of which contribute to genetic diversity. In contrast, mitosis produces genetically identical daughter cells without these mixing processes.

10. Who proposed the concept that meiosis involves two successive divisions following a single DNA replication, leading to the formation of haploid cells?

A. Theodor Boveri

B. Walter Sutton

C. Hugo de Vries

D. August Weismann

Answer: (B)

Explanation

Walter Sutton proposed the chromosomal theory of inheritance and described how meiosis involves two divisions, which produce haploid cells from a diploid parent. The other scientists contributed to genetics but did not specifically formulate this meiotic process.

11. What is the primary consequence of meiosis I being reductional in nature?

A. It prevents crossing-over between homologous chromosomes.

B. It doubles the chromosome number in the daughter cells.

C. It reduces the chromosome number from diploid to haploid in the daughter cells.

D. It results in the formation of genetically identical daughter cells.

Answer: (C)

Explanation

Meiosis I is reductional because it separates homologous chromosomes, reducing the chromosome number from diploid (2n) to haploid (n). This is essential for producing gametes with half the chromosome number of somatic cells, ensuring genetic stability across generations.