Question

The figure given below shows the sectional view of the ovary. Select the option which gives correct identification of marked structure (A to D) and its feature.

• A. B : Corpus luteum, it cannot be formed and added after birth
  
• B. C : Graafian follicle, mature follicle which ruptures to release secondary oocytes.
  
• C. D : Tertiary follicle, a large number of this mother cell degenerates during the phase from birth to puberty
  
• D. A : Primary follicle, it is also called gamete
  

Answer 1

The correct option is B C : Graafian follicle, mature follicle which ruptures to release secondary oocytes.


Labelled diagram of Ovary
The given image represents the labelled diagram of the sectional view of the ovary.

Label ‘A’
The part labelled as 'A' is the primary follicle. It is the follicle with two layers of granulosa cells. It possesses a primary oocyte arrested at prophase I of meiosis I. A female has only $60,000-80,000$ primary follicles at puberty because from birth to puberty a large number of primary follicles degenerates.

Label ‘B’
The part labelled as 'B' is a tertiary follicle. Tertiary follicle is formed by the transformation of the secondary follicle. It contains a fluid filled cavity called antrum.

Label ‘C’
The part labelled as 'C' is the Graafian follicle. Graafian follicle is formed by the transformation of the tertiary follicle, which ruptures and releases the secondary oocyte by ovulation.

Label ‘D’
The part labelled as 'D' is corpus luteum. Corpus luteum is formed by the transformation of the remnants of Graafian follicle after ovulation. It secretes a large amount of progesterone to maintain the thickness of the endometrium.