Science Chapter 08: Reproduction in Plants

Class 07 Science NCERT

All organisms multiply or reproduce their own kind. In plants there are two modes of reproduction, asexual and sexual. There are several methods of asexual reproduction such as fragmentation, budding, spore formation and vegetative propagation.

Sexual reproduction involves the fusion of male and female gametes.

In vegetative propagation new plants are produced from different vegetative parts such as leaves, stems and roots.

Flower is the reproductive part of a plant. A flower may be unisexual with either the male or the female reproductive parts. A bisexual flower has both the male and the female reproductive parts.

The male gametes are found inside the pollen grains and female gametes are found in the ovule. Pollination is the process of transfer of pollen grains from the anther of one flower to the stigma of the same or another flower. Pollination is of two types, self-pollination and cross-pollination.

In self-pollination, pollen grains are transferred from the anther to the stigma of the same flower. In cross-pollination, pollen grains are transferred from the anther of one flower to the stigma of another flower of the same kind.

Pollination takes place in plants with the help of wind, water and insects. The fusion of male and female gametes is called fertilisation. Fertilised egg is called zygote. Zygote develops into an embryo.

Fruit is the mature ovary whereas ovule develops into a seed, which contains the developing embryo.

Seed dispersal is aided by wind, water and animals. Seed dispersal helps the plants to (i) prevent overcrowding, (ii) avoid competition for sunlight, water and minerals and (iii) invade new habitats.