In self-pollination, the pollens are deposited on the stigma of either the same flower or another flower on the same plant. In cross-pollination, pollens are deposited from one flower to another flower of the same kind, borne on another plant.
The process of fertilisation takes place after pollination. Pollens on reaching the stigma of the flower germinate to form pollen tubes that carry male gametes. One of the male gametes fuses with female gamete on reaching ovary forming zygote.
In asexual reproduction, single parent gives rise to the offspring without producing seeds whereas, in sexual reproduction two parents of opposite sex participate to produce a seed from which a new individual emerges.
Sexual reproduction is the process of producing offspring by an organism with involvement of male and female sexes. It involves fusion of male and female gametes that leads to the formation of zygote. The male and female gametes are produced by male and female flower parts, respectively. Male part of the plant is stamen that bears male gametes inside the pollens and female part of the plant is pistil that bears ovary containing female gamete or ovum. Pollens fall on stigma of the flower and germinate to form pollen tubes containing male gametes. Pollen tube enters the ovary releasing male gametes. One of the gametes fuses with ovum and undergo fertilisation to form zygote, completing the process of sexual reproduction.
(a) The reproductive part of a plant is the (iv) flower
(b) The process of fusion of the male and the female gametes is called (i) fertilisation
(c) Mature ovary forms the (iv) fruit
(d) A spore producing plant is (ii) bread mould
(e) Bryophyllum can reproduce by its (ii) leaves
Column I | Column II |
(a) Bud | (i) Maple |
(b) Eyes | (ii) Spirogyra |
(c) Fragmentation | (iii) Yeast |
(d) Wings | (iv) Bread mould |
(e) Spores | (v) Potato |
(vi) Rose |
The correctly matched contents of Column I with Column II are as follows:
Column I |
Column II |
(a) Bud |
(iii) Yeast |
(b) Eyes |
(v) Potato |
(c) Fragmentation |
(ii) Spirogyra |
(d) Wings |
(i) Maple |
(e) Spores |
(iv) Bread mould |
Seed are carried by wind, water and animals for dispersal.
Various male and female reproductive parts of the flower can be sketched as follows:
There are four different methods of asexual reproduction which are as follows:
Fragmentation- In this process, an organism, like algae, breaks down into two or more fragments and each fragment gives rise to a new individual. For example, Spirogyra undergoes fragmentation as shown below:
(a) Vegetative propagation
(b) Unisexual flower
(c) Self-pollination
(d) Fertilisation
(e) wind, water and animals
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