Question

Figure A shows the diagrammatic sectional view of ovary and figure B shows the schematic representation of oogenesis in human female.


Identify the correct stage of oocyte or its meiotic product present in the structures X, Y and Z respectively in the diagrammatic sectional view of ovary (Figure A).
Choose the correct option from the table below.
​​​​​​​[0.7 mark]

• A.

  X	Y	Z
  Primary oocyte	Secondary oocyte	Second polar body

• B.

  X	Y	Z
  Oogonia	Primary oocyte	Ovum

• C.

  X	Y	Z
  Oogonia	Secondary oocyte	Ovum

• D.

  X	Y	Z
  Primary oocyte	First polar body	Secondary oocyte

Answer 1

The correct option is D

X	Y	Z
Primary oocyte	First polar body	Secondary oocyte

Primary oocyte surrounded by single layer of granulosa cells is called primary follicle. Primary oocyte starts meiosis-I but get arrested at prophase-I within primary follicle. The oocyte in secondary follicle is also primary oocyte suspended at prophase-I. Primary oocyte completes its 1st meiotic division to form secondary oocyte and first polar body within tertiary follicle. Secondary oocyte starts meiosis-II and get arrested at metaphase-II within tertiary follicle. The oocyte within Graafian follicle is also secondary oocyte suspended at metaphase-II. Hence, the correct option is d.