Question

9. Draw a neat labelled diagram to explain plant fertilization. Write

few points on pollen grains​

Answer 1

Answer:

pollen grains are the male gametophyte that contain the male gametes

A pollen grain consist of two layer covering-

● Outer layer - Exine

● Inner layer - Intine

☆ Exine

it is made up of sporopollenin which make it resistant to environment, acid , pest , temperature

and due to the presence of this sporopollenin , pollen grains are also found in the form of fossils

■■》 At some places the deposition of sporopollenin on exine is absent that is known as germ pore

after pollination, pollen tube emerge from this germ pore

Answer 2

[Diagram is in Attachment !!]

# POLLEN GRAINS :-

1. The anther produces pollen grains.
2. When pollen grains reach the stigma of a plant they release some liquid substance. Which was absorbed by stigma. Then stigma make pollen tube, which ultimately reach the ovule of the ovary.
3. The pollen grains travel through the pollen tube towards ovule.
4. When a pollen grain (male gamete) fuse with egg then it forms zygote, by the process of Fertilization.
5. And when another pollen grain (male gamete) fuse with polar nuclei, then it forms primary endosperm nucleus.

• Sine, fusion occurs times so it is known as Double fertilization in plants.
• After it the zygote develops into embryo and the primary endosperm nucleus into endosperm which provides nourishment to the developing embryo.
• After it the ovary develops into fruit and ovule into seeds.