Question

Polar body is produced during formation of
(a) Sperm
(b) Secondary oocyte
(c) Oogonium
(d) Spermatocytes

Answer 1

Hint: Oocyte produced after the meiosis-I of the primary oocyte. The new offspring will depend on this oocyte for the cytoplasm, cellular material, so this oocyte undergoes unequal division to form two to three polar bodies.

Complete answer:
The primary oocytes that are diploid (2n) are arrested (paused) at prophase I of meiosis I. When a female undergoes ovulation once a month, one of these follicles with the primary oocyte matures. It fully undergoes meiosis- I and result in two different structure:
One haploid (n) secondary oocyte. It contains half the number of chromosomes but still has sister chromatids.
One haploid (n) structure is called the polar body.
The Polar body does not go to become an egg. Through unequal cytokinesis, the secondary oocytes get most of the cytoplasm and the polar body left with little cytoplasm.
So, the correct answer is, ‘secondary oocyte.’

Additional Information:
- Oogenesis is the period of growth differentiation and maturation occurring in the female gonads or ovaries during which the egg or ovum acquires its developmental potential.
- Ovum is a unique cell which has all the properties to develop into a new individual when segregated from the organism.
- There are 5 stages of oogenesis process:
Stage I- The germinal epithelial cells divide repeatedly until many diploid oogonia are formed.
Stage II- The oogonia grow to form primary oocytes that surround by a layer of follicle cells.
Stage III- The follicle cells surrounding the primary follicle develop into the secondary follicle.
Stage IV- The follicle layer of the secondary oocytes thickness and folds to form the graafian follicle.
Stage V- When the grain follicle becomes mature, it will move towards the surface of the very wall and rupture to release the secondary oocyte.

Note:
- Phase of oogenesis:
Pre meiotic phase
- The primordial germ cell migrates from the endosperm.
- They multiply to form oogonia initiating the multiplication phase.
- Thus leading to the formation of primary oocytes.
Meiotic phase
- This is a differentiation phase where primary and secondary oocytes formation takes place.
- It include various sub- stages namely:
   Pre-Vitellogenesis
   Vitellogenesis