Question

Exine of pollen grain is made up of
a. Pectocellulose
b. Ligno cellulose
c. Sporopollenin
d. Pollen kit

Answer 1

Hint: Pollen grains are microscopic reproductive structures found in plants. They carry male reproductive cells or male gametes (tube nucleus and generative nuclei) from one plant to another plant.

Complete answer:
> Option A:
Pectocellulose is a special form of cellulose that is found in fibers – flax fiber and in the stem of the family Gramineae.

> Option B:
Lignocellulose is found in lignified tissues. It is present in jute fibers. It is the plant's dry mass and it is one of the most abundant raw materials used for the production of biofuel – ethanol.

> Option C:
Sporopollenin is one of the most inert (chemically) biological polymers. It is found in the outer covering of pollen grains and other plant spores. It is very stable and it remains unaffected in soil and other deposits (sediments) for a longer duration.

> Option D:
Pollen kit is found on the outer covering or exine of pollen grains. It is a sticky covering that is found in the pollen grains of those plants, which are pollinated by insects as it helps to stick to insects and dispersal of pollen.

Hence, the correct answer is option (C).

Note: The pollen grains are produced by male flowers. These are spherical shaped male reproductive structures which contain one tube nuclei and two germinative nucleuses. It is a hard structure that contains two layers or walls. The outer layer is called exine and also called exospore and the internal wall is called intine or endospore. Exine is made up of sporopollenin while intine is made up of cellulose. They germinate when they are transferred on the stigma of female flowers and produce a pollen tube to transfer male gametes into the ovary or pistil.