CBSE Class 7 Answered

Hi Shanthini,

Plants reproduce through either sexual or asexual means.

Sexual reproduction involves pollination helped by wind or insects whereas asexual reproduction involves tubers, bulbs and runners known as rhizomes and stolons as well as cuttings taken by humans for commercial and home growing.

For example,

Vegetative Propagation: 

When a new plant is developed by a vegetative part; such as root, stem or leaf; it is known as vegetative propagation. Eg- When the tuber of potato is cut into several pieces and each piece bears an ‘eye’; each piece produces a new plant.  The leaf of bryophyllum produces new plants through its notches.

Sexual Reproduction: 

When two parents are involved in the process, it is called sexual reproduction. Two gametes, viz. male and female gametes, are formed. The fusion of male and female gametes is called fertilization. Zygote is formed after fertilization. The zygote develops into an embryo and finally into a new individual.Flower is a special organ of flowering plants (angiosperms) which works as the reproductive system.

Fertilization in Plants

The fusion of the male gamete and the female gamete is called fertilization. When pollen settles on top of the stigma, it germinates to produce a pollen tube. The pollen tube enters the ovary through the style. Male nuclei are transferred to the ovary, through the pollen tube. The cell formed, just after fertilization, is called zygote. Zygote develops into embryo. Each embryo develops into a seed. The seed is an embryo which is enclosed in a protective coat. The ovary gets transformed into fruit.