Question

Identify the various shapes and structures of pollen grains.
Briefly explain the reproductive structure of flowering plant

Answer 1

Answer:

ANSWER

The androecium is the male reproductive whorl of the flower which produces male gametes. The stamen is the androecium composed of anther and filament. The anther contains pollen sacs which produce pollen grains.The pollen grain is the male gametophyte which contains the male gametes. The pollen grain is surrounded by two layers as exine which forms the outer layer and intine which forms the inner layer. The generative cell divides to form the two male gametes. The vegetative cell is responsible for the providing nutrition. The intine layer comes out of the germ pore to form the pollen tube.

Answer 2

Answer:

1) Pollen grains vary in size, shape, and surface characteristics depending on the plant species (shown below). In general, pollen grains have a double wall consisting of a thin inner wall composed of cellulose, termed the endospore, and a thick outer wall comprised of sporopollenin, termed the exospore.

2) Sterile parts of flowers are the sepals and petals. When these are similar in size and shape, they are termed tepals. Reproductive parts of the flower are the stamen (male, collectively termed the androecium) and carpel (often the carpel is referred to as the pistil, the female parts collectively termed the gynoecium).

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