Question

Select the correct statement/s from the following:

• [A.] Spermatogonia always undergo meiotic cell division.
• [B.] Primary spermatocytes divide by mitotic cell division.
• [C.] Secondary spermatocytes have 23 chromosomes and undergo second meiotic division.
• [D.] Spermatozoa are transformed into spermatids.

• A. A and C only
• B. C only
• C. D only
• D. B and C only

Hint:

The haploid phase of spermatogenesis begins from secondary spermatocyte stage.

Answer 1

The Correct Option is B

Concept: Spermatogenesis is the process of sperm formation inside seminiferous tubules of testes. It involves three major phases:

• Multiplication phase
• Meiotic phase
• Spermiogenesis

Different stages of spermatogenesis involve different types of cell divisions and chromosome numbers.

Step 1: Analyze statement A carefully.
Spermatogonia are diploid germ cells present at the basal region of seminiferous tubules. Their primary role is to multiply by mitotic divisions to maintain germ cell population. Only some spermatogonia differentiate into primary spermatocytes which later undergo meiosis. Therefore, spermatogonia do not always undergo meiotic division. Hence, statement A is incorrect.

Step 2: Analyze statement B carefully.
Primary spermatocytes are diploid cells formed from spermatogonia. These cells undergo Meiosis I, not mitosis. The first meiotic division reduces chromosome number from diploid to haploid and produces secondary spermatocytes. Hence, statement B is incorrect.

Step 3: Analyze statement C carefully.
Secondary spermatocytes are haploid cells containing 23 chromosomes. These cells undergo Meiosis II to produce spermatids. Since this statement correctly describes chromosome number and type of division, statement C is correct.

Step 4: Analyze statement D carefully.
Spermatids transform into spermatozoa through a differentiation process called spermiogenesis. The statement given in the question reverses the process incorrectly. Therefore, statement D is incorrect.

Step 5: Determine the correct answer.
Only statement C is correct. Hence, the correct answer is: \[ \boxed{\text{C only}} \]