Question

What words will correct fill $\left(a\right)$ , $\left(b\right)$ , $\left(c,\right)$ and $\left(d\right)$ in the following paragraph?

$\left(a\right)$ develops into a pollen grain. The outer layer is $\left(b\right)$ and inner layer is intine. The inner layer is made up of cellulose and $\left(c\right)$ . In 60% of the angiosperms, pollen grains are shed at $\left(d\right)$ celled stage.

• A. $\left(a\right)$ - Anther, $\left(b\right)$ - Exine, $\left(c\right)$ - Chitin, $\left(d\right)$ - 3
• B. $\left(a\right)$ - Microspore, $\left(b\right)$ - Exine, $\left(c\right)$ - Chitin, $\left(d\right)$ - 2
• C. $\left(a\right)$ - Anther, $\left(b\right)$ - Exine, $\left(c\right)$ - Pectin, $\left(d\right)$ - 2
• D. $\left(a\right)$ - Microspore, $\left(b\right)$ - Exine, $\left(c\right)$ - Pectin, $\left(d\right)$ - 2

Answer 1

Answer: (D)

The microspore develops into a pollen grain. The outer layer is exine. The inner layer is called intine and it is made up of cellulose and pectin. In 60% angiosperms, pollen grains shed at 2 - celled stage. In others, they are shed at 3 celled stages as the generative cell divides mitotically to form 2 male gametes.