Curriculum

Science Grade IX

Science Grade 9

0/13

Worksheets

0/1

Assignments

0/1

Text lesson

Chapter 11: Reproduction: How Life Continues

Grade 9 Science | Chapter 11

Reproduction: How Life Continues

How do living things make more of their own kind? This chapter compares asexual and sexual reproduction and looks at the flower as the reproductive part of a plant.

Core Concepts

Key Principles

Worked Examples

Practice Sets

Contents

Introduction: Why Reproduction Matters

Asexual Reproduction

Sexual Reproduction

The Flower: A Plant’s Reproductive Organ

From Pollination to Seed

Variation and Survival

Key Reasoning (Principles)

Worked Examples (10)

Practice Sets A to D

10.

Summary and Exam Quick-Check

1. Introduction: Why Reproduction Matters

Reproduction is the process by which living things produce new individuals of their own kind. No organism lives forever, so reproduction is how a species continues across generations. There are two broad ways it happens: asexual reproduction, which involves a single parent, and sexual reproduction, which usually involves two.

This chapter, now placed in Class 9, compares the two methods, looks closely at the flower as the reproductive organ of many plants, and explains why the variation produced by sexual reproduction is so valuable for survival.

Core idea

Reproduction produces new individuals so a species can continue. Asexual reproduction needs one parent and gives identical offspring; sexual reproduction usually needs two and gives varied offspring.

2. Asexual Reproduction

In asexual reproduction a single parent produces offspring that are genetically identical to it. Common methods include binary fission, where a single-celled organism splits into two, and budding, where a small outgrowth on the parent grows and then separates. Asexual reproduction is fast and needs no partner, but the offspring show little variation.

Diagram 1 – Asexual Reproduction

Binary fission showing one cell splitting into two, and budding showing a bud growing and separating

Fig 1. In binary fission one cell divides into two identical cells; in budding a small bud grows on the parent and then separates.

3. Sexual Reproduction

In sexual reproduction, special cells called gametes from two parents join in a process called fertilisation. Because the offspring receive a mix of features from both parents, they are not identical to either parent or to one another. This mixing is the source of variation, which is the main advantage of sexual reproduction.

Feature

Asexual

Sexual

Number of parents

One

Usually two

Offspring

Identical to parent

Varied, a mix of both parents

Speed

Fast

Slower

Variation

Very little

Plenty

4. The Flower: A Plant’s Reproductive Organ

In many plants the flower is the reproductive organ. Its outer green sepals protect the bud, and the coloured petals often attract pollinators. The male part, the stamen, has an anther that makes pollen on a stalk called the filament. The female part, the carpel, has a sticky stigma, a style, and an ovary that holds the ovules.

Diagram 2 – Parts of a Flower

Labelled flower showing sepal, petal, anther, filament, stigma, style and ovary

Fig 2. A flower showing sepals, petals, the stamen (anther and filament) and the carpel (stigma, style and ovary).

5. From Pollination to Seed

Pollination is the transfer of pollen from an anther to a stigma, carried by wind, water or animals. After pollination, a male cell from the pollen joins an egg cell in the ovule during fertilisation. The fertilised ovule grows into a seed, and the ovary often grows into a fruit that protects and helps spread the seeds.

6. Variation and Survival

Because sexual reproduction mixes features from two parents, the offspring vary from one another. This variation means that if conditions change, some individuals may have features that help them survive. Over many generations, this is how populations are able to adapt, which is why the variation from sexual reproduction is so important.

Watch out

Asexual offspring are identical, so a single harmful change could affect all of them. Sexual reproduction spreads the risk by producing varied offspring.

7. Key Reasoning (Principles)

Principle 1: One parent gives identical offspring

Asexual reproduction copies a single parent, so the offspring are genetically identical, with very little variation.

Principle 2: Two parents give variation

Sexual reproduction mixes features from two parents, so the offspring differ from each other, creating variation.

Principle 3: Variation aids survival

When offspring vary, some may cope better with a change in conditions, helping the population survive over time.

8. Worked Examples

Example 1

Q: Define reproduction.

▶ Show Solution

Reproduction is the process by which living things produce new individuals of their own kind.

Answer: Producing new individuals of the same kind.

Example 2

Q: Name the two main types of reproduction.

▶ Show Solution

The two types are asexual and sexual reproduction.

Answer: Asexual and sexual reproduction.

Example 3

Q: Which type of reproduction needs only one parent?

▶ Show Solution

Asexual reproduction needs a single parent.

Answer: Asexual reproduction.

Example 4

Q: Name the process where a single cell splits into two.

▶ Show Solution

A single cell dividing into two is binary fission.

Answer: Binary fission.

Example 5

Q: Name the male part of a flower.

▶ Show Solution

The stamen, made of anther and filament, is the male part.

Answer: The stamen (anther and filament).

Example 6

Q: Name the female part of a flower.

▶ Show Solution

The carpel, made of stigma, style and ovary, is the female part.

Answer: The carpel (stigma, style and ovary).

Example 7

Q: What is pollination?

▶ Show Solution

Pollination is the transfer of pollen from an anther to a stigma.

Answer: Transfer of pollen from anther to stigma.

Example 8

Q: What grows from a fertilised ovule?

▶ Show Solution

A fertilised ovule develops into a seed.

Answer: A seed.

Example 9

Q: Why do offspring from sexual reproduction show variation?

▶ Show Solution

They receive a mix of features from two parents, so they differ.

Answer: Because they mix features from two parents.

Example 10

Q: Give one advantage of asexual reproduction.

▶ Show Solution

It is fast and needs no partner.

Answer: It is fast and needs only one parent.

9. Practice Sets A to D

Set A – Multiple Choice (Basic)

1. Reproduction with a single parent is: (a) sexual (b) asexual (c) pollination (d) fertilisation

2. Binary fission is an example of: (a) sexual reproduction (b) asexual reproduction (c) pollination (d) variation

3. The male part of a flower is the: (a) carpel (b) stigma (c) stamen (d) ovary

4. Transfer of pollen to a stigma is called: (a) fertilisation (b) pollination (c) budding (d) fission

5. A fertilised ovule grows into a: (a) flower (b) seed (c) petal (d) sepal

▶ Reveal Answers

1. (b) asexual.

2. (b) asexual reproduction.

3. (c) stamen.

4. (b) pollination.

5. (b) seed.

Set B – Short Answer (Understanding)

1. State one difference between asexual and sexual reproduction.

2. Name two methods of asexual reproduction.

3. What is fertilisation?

4. Why are the petals of many flowers brightly coloured?

5. What is the main advantage of sexual reproduction?

▶ Reveal Answers

1. Asexual needs one parent and gives identical offspring; sexual usually needs two and gives varied offspring.

2. Binary fission and budding.

3. The joining of a male gamete with a female gamete to form a new cell.

4. To attract pollinators that carry pollen from flower to flower.

5. It produces variation, which can help a population survive changing conditions.

Set C – Application and Reasoning

1. A pond organism reproduces by splitting in two. Name the method.

2. Why do offspring of asexual reproduction look identical to the parent?

3. Identify the parts of the carpel.

4. Explain why a flower needs both an anther and a stigma.

5. Suggest why variation is useful if the climate changes.

▶ Reveal Answers

1. Binary fission.

2. Because they come from a single parent and are genetic copies of it.

3. Stigma, style and ovary.

4. The anther makes pollen (male), and the stigma receives pollen so that fertilisation can occur (female).

5. Some varied individuals may have features that suit the new climate, so they survive and reproduce.

Set D – Higher Order (Challenge)

1. Compare the advantages and disadvantages of asexual and sexual reproduction.

2. Trace the steps from pollination to the forming of a seed.

3. Explain why a disease could wipe out a whole population produced asexually.

4. Why might a plant produce brightly coloured, scented flowers rather than dull ones?

5. Explain how variation links reproduction to the survival of a species.

▶ Reveal Answers

1. Asexual is fast and needs one parent but gives no variation; sexual is slower and needs two parents but gives variation that aids survival.

2. Pollen is transferred to the stigma (pollination), a male cell joins an egg in the ovule (fertilisation), and the fertilised ovule grows into a seed.

3. All the offspring are identical, so if the disease harms one, it can harm them all in the same way.

4. Bright colour and scent attract pollinators, improving the chance of pollination and successful reproduction.

5. Sexual reproduction creates varied offspring; when conditions change, some variants survive, so the species continues.

Chapter Summary

Reproduction

Producing new individuals so a species continues across generations.

Asexual

One parent, identical offspring, fast, with little variation; for example fission and budding.

Sexual

Usually two parents, varied offspring, through gametes and fertilisation.

The Flower

The reproductive organ: sepals, petals, stamen (male) and carpel (female).

Pollination to Seed

Pollen reaches the stigma, fertilisation follows, and the ovule becomes a seed.

Variation

Sexual reproduction mixes features, helping a population survive change.

Quantity

Unit

Symbol

Male part

stamen

anther + filament

Female part

carpel

stigma + style + ovary

Single-parent split

binary fission

–

8-Point Exam Quick-Check

Reproduction produces new individuals so a species continues.

Asexual reproduction needs one parent and gives identical offspring.

Binary fission and budding are forms of asexual reproduction.

Sexual reproduction usually needs two parents and gives varied offspring.

In a flower the stamen is male (anther and filament) and the carpel is female.

Pollination is pollen reaching the stigma; fertilisation follows.

A fertilised ovule develops into a seed.

Variation from sexual reproduction helps a population survive change.

School Revise Virtual Lab

Explore these ideas with interactive simulations and visual tools.

Open the Virtual Lab →

Class 9 Science Chapter 11: Reproduction, How Life Continues, Complete Notes and Practice

This revision guide follows the NCERT 2026 to 27 Exploration syllabus and explains how living things continue, covering asexual reproduction such as binary fission and budding, sexual reproduction and fertilisation, the parts of a flower, pollination and seed formation, and the value of variation for survival, with two labelled diagrams, ten worked examples and graded practice. Visit SchoolRevise.com to revise, practise and excel.