Reproduction In Plants

a. vegetative propagation.

Vegetative propagation is a type of asexual reproduction in which new plants are produced from roots, stems, leaves and buds.

b. unisexual flowers.

The flowers which contain either only the pistil or only the stamens are called unisexual unisexual unisexual flowers. Example-Papaya and cucumber produce unisexual flower

c. pollination

The means of pollination are wind, water and insects.

d. fertilization

Fertilization results in the formation of zygote which begins to develop into an Embryo.

e. wind, insect, water.

Seeds and fruits of plants are carried away by wind, water and animals.

Various methods of asexual reproduction are:

(1) Vegetative propagation: Vegetative propagation is the method of asexual reproduction in which new plants produced from the vegetative parts of the plant like stems, roots, and leaves. Example: Potato, Bryophyllum can be reproduced by vegetative propagation by using either a piece of its stem or leaves. The leaves of a Bryophyllum have special buds on their margins which may fall on the soil and develop into a new plant

(2) Budding: In budding, the specific site of the parent body grows as an outgrowth called bud which then detaches and becomes a new organism. Example, Yeast, and Hydra reproduce by budding.

(3) Fragmentation: In this method, an organism breaks into smaller pieces or fragments which grow into new organisms. This type of reproduction is common in algae. When water and nutrients are available, algae grow and multiply rapidly by fragmentation. Algae break into two or more fragments which later on grow into new individuals. This process continues, and they cover a large area in a short period. example spirogyra, molds, etc

The reproduction in which fusion of male and female gametes is involved, is called sexual reproduction. The cells involved in sexual reproduction are called gametes. Fertilization is the step of reproduction in which fusion of gametes take place to form zygote. After fertilisation, the zygote gradually divides to form an embryo within the ovule. The ovary of the flower develops and becomes a fruit with seeds inside it. The seeds develop from the ovules. The seed contains an embryo enclosed in a protective seed coat.

The differences between asexual and sexual reproduction are given as below:

The flower is the reproductive part of the plant. The main parts of the plants are:
1) Petals - The leaf like structures that protect the reproductive parts of the flower.

2) Sepals – The sepal’s function is to protect the flower bud.

3) Carpels - It is the female reproductive organ in the plants.

4) Stamens – It is the male reproductive organ in the plants.

Fig. Reproductive Parts

Self-pollination: when pollen grains of a flower are transferred to the stigma of the same flower (or another flower on the same plant) is known as self-pollination.

Cross-pollination: When pollen grains of one flower are transferred to the stigma of another plant is known as cross-pollination.

The figure is shown below:

Fertilization is the union of male and female gametes to form zygote.

Fertilization begins when a pollen grain lands on the stigma of the carpel. Then it bursts open and forms a pollen tube. Pollen tube downwards through the style and finally reaches the ovule in the ovary. The male gamete present in the pollen grain moves through the pollen tube and fertilizes the ovum present in the ovule, i.e., fertilization takes place. The fertilization leads to the formation of zygote which later develops into an embryo. The following picture shows the fertilization in plants:

The process of spreading seeds to different places is called dispersal of seeds. Seeds and fruits are dispersed by different places by wind, water and animals.

(i) By Wind: Some seeds are light-weight and some have hair-like or wing-like structure on them. These seeds float on air and are dispersed by wind. Example- drumstick, maple, etc.

(ii) By Water: Some seeds are dispersed by water. It takes place in some aquatic plants and in some which grow near water body. These fruits or seeds usually develop floating ability in the form of spongy or fibrous outer coat as in coconut.

(iii) By animal: Some seeds are dispersed by animals. Such seeds have spine like structure through which they get attached to the bodies of animals and are carried to distant places. Examples are Xanthium and Urena.

Column I Column II

a. Bud iii. Yeast

In budding, specific site of the parent body grows as an outgrowth called bud which then detaches and becomes a new organism. Yeast reproduces by budding.

b. Eyes v. Potato

Potato have scars on them which are called eyes.

c. Fragmentation ii. Spirogyra

Spirogyra is an alga which grow and multiply rapidly by fragmentation. In this type of reproduction, an alga breaks up into two or more fragments. These fragments or pieces grow into new individuals.

d. Wings i. Maple

Maple seeds are light-weight and have wing-like structure on them. These seeds float on air and are dispersed by wind.

e. Spores iv. Bread mould

Rhizopus fungus (bread mould) reproduces by spore formation. It is asexual method of reproduction.

Answer: Leaves

Bryophyllum can reproduce by vegetative propagation which is a type of asexual reproduction.

The leaves of a Bryophylum have special buds on their margins which may fall on the soil and develop into new plant.

Flower is the reproductive part of a plant. Stamens are the male reproductive part and the pistil is the female reproductive part of a flower.

Fertilization is the union of male and female gametes to form zygote.

After fertilization, the zygote gradually divides to form an embryo within the ovule. The ovary of the flower develops and becomes a fruit with seeds inside it. The seeds develop from the ovules.

Bread mould (a fungus) reproduces by spore formation. It is asexual method of reproduction.