MHT CET · BIOLOGY · STD 12 - 1. Reproduction in Lower and Higher Plants

Identify the correct ratio of male gametes, vegetative cells, generative cells and microspore mother cells produced in a microsporangium if 80 pollen grains are released from it.

A 1 : 1 : 1 : 1
B 1 : 4 : 4 : 8
C 2 : 1 : 1 : 4
D 8 : 4 : 4 : 1

Verified Solution

Answer & Solution

Correct Answer

(D) 8 : 4 : 4 : 1

Step-by-step Solution

Detailed explanation

i. 1 microspore mother cell gives 4 pollen grains → 80/4 = 20 microspore mother cells
ii. Each pollen grain at maturity has 1 vegetative + 1 generative cell → 80 pollen grains will have 80 generative cells and 80 vegetative cells.
iii. Mitotic division of each generative cell gives rise to 2 male gametes → 80 generative cells x 2 = 160 male gametes.
iv. Ratio = 160 : 80 : 80 : 20
= 8 : 4 : 4 : 1

Apply the relevant identity from the chapter and substitute the values established in the previous step, keeping the original constraint in view.

Use the simplified expression to isolate the unknown, then plug the result back into the question setup to confirm the working is internally consistent.

Cross-check against a boundary or limiting case. Both the dimensional balance and the qualitative behaviour at the extreme should agree with the candidate answer.

Combine the steps above to identify the correct option. The remaining choices each fail at least one of the consistency, dimensional, or boundary checks.

Same subject

Match Assisted Reproductive Technologies in column I with their process in column II and select the correct option

	Column I		Column II
a.	ZIFT	i.	Single sperm cell is injected directly in cytoplasm of an ovum
b.	GIFT	ii.	Fertilized egg is transferred to fallopian tube for further development
c.	ICSI	iii.	Sperms are introduced into the Uterus
d.	IUI	iv.	Ova and sperms are directly injected into regions of the oviduct where fertilization occurs.

MHT CET 2022 Easy

Explore more questions on app

From MHT CET

Explore more questions on app