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 following cells in the ovary in sequential order, we will analyze the development stages of oogenesis:

1. **Primary Oocyte**: The process begins with the formation of gamete mother cells known as oogonia. After birth, these oogonia undergo mitotic divisions to form primary oocytes. Therefore, the first step in our sequence is the formation of the primary oocyte.

2. **Primary Follicle**: Once the primary oocyte is formed, it becomes surrounded by a layer of granulosa cells. This structure, consisting of the primary oocyte and the surrounding granulosa cells, is referred to as the primary follicle. Thus, the second step in our sequence is the formation of the primary follicle.

3. **Graafian Follicle**: The primary follicle undergoes further development to become a Graafian follicle (also known as a mature follicle). This follicle is characterized by a larger size and the presence of a mature oocyte. Therefore, the third step in our sequence is the formation of the Graafian follicle.

4. **Ovum**: Finally, during the process of ovulation, the Graafian follicle releases the mature ovum. This is the last step in our sequence.

Putting it all together, the correct sequential order of formation is:
1. Primary Oocyte
2. Primary Follicle
3. Graafian Follicle
4. Ovum

### Summary of the Sequential Order:
1. Primary Oocyte
2. Primary Follicle
3. Graafian Follicle
4. Ovum