Question

There are $10$ flowers in one individual plant of Crotalaria. In each microsporangium of every stamen of all flowers, there are $30$ microspore mother cells. How many pollen grains are formed from the plant?
(A) $4000$
(B) $10,000$
(C) $24,000$
(D) $48,000$

Answer 1

Hint: The Crotalaria is the flower plant that belonged to the Fabaceae. These are otherwise called as the rattle pods and are commonly called by the name sunn hemp. It is used as the crop for the green manure, lignified fiber and a fodder for the cattle.

Complete Answer:
It is given that
- Number of flowers in the plant of Crotalaria = 10
- Number of microspore mother cells in the microsporangium = 30
- In a Crotalaria plant, each flower of this plant has 10 stamens. In each stamen there is 4 microsporangia.
- Number of microsporangia = $10 \times 4$
- Number of microsporangia = 40

In these microsporangia, there will be the microspore mother cells. These mother cells help in the production of the pollen grains. Each microspore mother cell may give rise to 4 pollen grains.
- Number of pollen grains = $40 \times 4$
- Number of pollen grains = 160

There are 30 microspore mother cells in each microsporangium.
- Number of pollen grains = $160 \times 30$
- Number of pollen grains = 4800

It is given that there are 10 flowers in one individual plant of Crotalaria. Hence the number of pollen grains in the plant of the crotalaria is calculated.
- Number of pollen grains = $4800 \times 10$
- Number of pollen grains = 48000 pollen grains
The single plant of crotalaria contains 48000 pollen grains.

Thus, the option (D) is correct.

Note: Some varieties of the crotalaria are toxic in nature. The source of harmfulness is the presence of pyrrolizidine alkaloids, which are noxious to winged animals and huge vertebrates. The pyrrolizidine alkaloids that are present in two sorts as monocrotaline and spectabiline.