Question

Which statement is true with respect to meiosis?

• A. Meiosis involves two sequential cycles of nuclear and cell division but only a single cycle of DNA replication.
• B. Meiosis involves one cycle of nuclear and cell division but two cycles of DNA replication.
• C. Four diploid cells are formed at the end of meiosis.
• D. Two haploid cells are formed at the end of meiosis.

Hint:

\[ {Meiosis} = 1 { DNA replication} + 2 { cell divisions} \Rightarrow 4 { haploid cells} \] {Remember:} DNA duplicates once before Meiosis I; Meiosis II occurs without another round of replication.

Answer 1

The Correct Option is A

Step 1: Understand the definition of meiosis.
Meiosis is a type of cell division that reduces the chromosome number by half and results in the formation of four haploid daughter cells. It is essential for sexual reproduction and occurs in gamete-producing cells.
Step 2: Know the stages involved in meiosis.
Meiosis consists of two successive divisions: Meiosis I and Meiosis II.
Meiosis I: Homologous chromosomes separate.
Meiosis II: Sister chromatids separate.
Step 3: DNA replication in meiosis.
DNA replication occurs only once — before Meiosis I — during the S-phase of the interphase. No DNA replication takes place before Meiosis II.
Step 4: Analyze the options.
Option (1) is correct: Two nuclear/cell divisions (Meiosis I and II) occur with only one round of DNA replication.
Option (2) is incorrect because it reverses the concept (only one division and two replications — which is false).
Option (3) is incorrect because meiosis produces haploid, not diploid, cells.
Option (4) is incorrect because meiosis results in four haploid cells, not two.