Arrange the formation of the following cells in the ovary the sequential order :
i) Ovum
ii) Primary follicle
iii) Primary oocytes
iv) Graffian follicle

Options

A. ii) , i) , iv) , iii)
B. iii) , ii) , i) , iv)
C. iii) , ii) , iv) , i)
D. i) , ii) , iii) , iv)

Answer

To arrange the formation of the cells in the ovary in sequential order, we need to understand the developmental stages of oocytes and follicles. Here’s the step-by-step solution:

1. **Primary Follicle (ii)**: The first stage in the development of an oocyte is the formation of the primary follicle. This structure consists of a primary oocyte surrounded by a layer of granulosa cells.

2. **Primary Oocyte (iii)**: Within the primary follicle, the primary oocyte is present. This is the immature egg cell that has begun the process of oogenesis but is arrested in prophase I of meiosis until ovulation occurs.

3. **Graafian Follicle (iv)**: As the primary follicle matures, it develops into a secondary follicle and eventually into a Graafian follicle. This is a mature follicle that contains a fully developed oocyte and is characterized by the presence of an antrum (a fluid-filled space).

4. **Ovum (i)**: Finally, during ovulation, the mature Graafian follicle releases the ovum, which is the mature egg ready for fertilization.

Putting it all together, the correct sequential order is:
- ii) Primary Follicle
- iii) Primary Oocyte
- iv) Graafian Follicle
- i) Ovum

Thus, the final order is: **ii, iii, iv, i**.