Question

Arrange the following stages of oogenesis in order of their occurrence:
(A) Ovum
(B) Oogonia
(C) Primary oocyte
(D) Secondary oocyte
Choose the correct answer from the options given below:

• A. (C), (B), (D), (A)
• B. (B), (C), (D), (A)
• C. (D), (C), (A), (B)
• D. (A), (D), (C), (B)

Answer 1

The Correct Option is B

To understand the correct order of the stages of oogenesis, we should first define each stage: 

• Oogonia (B): These are the initial germ cells in the ovaries, which proliferate by mitosis during fetal development.
• Primary oocyte (C): Oogonia develop into primary oocytes that initiate meiosis but halt at prophase I until puberty.
• Secondary oocyte (D): Upon maturation and ovulation, some primary oocytes resume meiosis and form secondary oocytes. This stage is arrested in metaphase II unless fertilization occurs.
• Ovum (A): The final mature egg cell, formed only if the secondary oocyte completes meiosis II after fertilization.

Following the natural biological progression, the correct sequence of stages during oogenesis is:

1. Oogonia (B)
2. Primary oocyte (C)
3. Secondary oocyte (D)
4. Ovum (A)

Therefore, the correct answer is: (B), (C), (D), (A)

Answer 2

(A) Ovum

The ovum is the final product of oogenesis. It is a mature egg cell that is ready for fertilization.

(B) Oogonia

Oogonia are the initial cells that give rise to the oocytes. They are the starting point of oogenesis.

(C) Primary oocyte

The primary oocyte is formed from the oogonia. It undergoes meiosis I to form the secondary oocyte.

(D) Secondary oocyte

The secondary oocyte is formed from the primary oocyte after meiosis I. It undergoes meiosis II to form the ovum.

Conclusion

The correct order of the stages of oogenesis is (B) Oogonia, (C) Primary oocyte, (D) Secondary oocyte, (A) Ovum. Therefore, the correct answer is (2) (B), (C), (D), (A).