Science Class 7 - Reproduction In-Plants Notes

Reproduction in Plants

Welcome to the chapter on Reproduction in Plants for Class 7. In this chapter, you will learn how plants make new plants, the different ways plants reproduce, and why reproduction is important for the survival of plants. By the end of this chapter, you will understand the main methods of plant reproduction and be able to explain them with examples!

Introduction

Reproduction is the process by which living things produce more of their own kind. Plants reproduce to ensure their species continues to live and grow. There are different ways plants reproduce.

Types of Plant Reproduction

• Sexual Reproduction: Involves flowers, seeds, and fruits.
• Asexual Reproduction: Does not involve seeds. New plants grow from roots, stems, or leaves.

Sexual Reproduction in Plants

Most plants reproduce sexually. The main parts involved are flowers, which have male and female parts.

• Stamen: The male part that makes pollen.
• Pistil: The female part that receives pollen.

When pollen from the stamen reaches the pistil, fertilization happens and seeds are formed. Seeds grow into new plants.

Asexual Reproduction in Plants

Some plants can make new plants without seeds. This is called asexual reproduction. It happens in different ways:

• By Roots: New plants grow from roots. Example: Carrot, sweet potato.
• By Stems: New plants grow from stems. Example: Potato (from tubers), ginger.
• By Leaves: New plants grow from leaves. Example: Bryophyllum.
• By Cuttings: A piece of stem or leaf is planted in soil to grow a new plant. Example: Rose, money plant.

Dispersal of Seeds

Seeds need to move away from the parent plant to grow well. This is called dispersal. Seeds are dispersed by:

• Wind (e.g., dandelion)
• Water (e.g., coconut)
• Animals (e.g., mango, berries)
• Explosion (e.g., pea, balsam)

Importance of Reproduction

• Helps plants survive and increase in number.
• Ensures food for animals and humans.
• Maintains balance in nature.

Fun Activity: Grow a Plant from a Cutting!

Take a small stem cutting from a money plant or rose. Put it in soil and water it. Watch how it grows into a new plant!

Summary

• Plants reproduce by sexual and asexual methods.
• Flowers, seeds, and fruits are important for sexual reproduction.
• Roots, stems, leaves, and cuttings help in asexual reproduction.
• Seed dispersal helps new plants grow in different places.

Practice Questions

1. Name two ways plants reproduce asexually.
2. What is the male part of a flower called?
3. How are seeds dispersed by animals?
4. Give one example of a plant that grows from a leaf.
5. Why is reproduction important for plants?

Challenge Yourself

• Draw and label the parts of a flower.
• List three plants that reproduce by stem cuttings.

Did You Know?

• Some seeds can stay in the soil for years before growing!
• Banana plants grow new plants from their underground stem called a rhizome.

Glossary

• Reproduction: Making new living things.
• Sexual reproduction: Making new plants using seeds from flowers.
• Asexual reproduction: Making new plants without seeds.
• Dispersal: Spreading seeds away from the parent plant.

Answers to Practice Questions

1. By stem cuttings, by leaves, by roots.
2. Stamen.
3. Animals eat fruits and drop seeds in new places.
4. Bryophyllum.
5. It helps plants survive and increase in number.

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Observe plants around you and see how they grow and reproduce!