What is Multiple Fission? – Complete NCERT Notes

Introduction

Multiple fission is a type of asexual reproduction in which a single parent organism divides into many daughter organisms at the same time. Unlike binary fission, where one parent produces two offspring, multiple fission results in the formation of numerous offspring from a single parent cell.

According to NCERT, multiple fission is commonly observed in organisms such as Amoeba under unfavorable conditions and in Plasmodium (the malarial parasite).

Definition of Multiple Fission

Multiple fission is the process of asexual reproduction in which the nucleus of a parent cell divides repeatedly to form many nuclei, followed by division of the cytoplasm, producing numerous daughter cells simultaneously.

Key Points

It is a form of asexual reproduction.
One parent produces many offspring.
The nucleus divides several times before the cell divides.
Offspring are genetically identical to the parent.
Helps organisms reproduce rapidly.

How Does Multiple Fission Occur?

The process takes place in the following steps:

Step	Process
1	The parent organism forms a protective cyst during unfavorable conditions.
2	The nucleus divides repeatedly by mitosis.
3	Many nuclei are formed inside the cyst.
4	Cytoplasm surrounds each nucleus.
5	Numerous daughter cells develop.
6	When conditions become favorable, the cyst breaks open.
7	Daughter organisms are released.

Multiple Fission in Amoeba

During unfavorable environmental conditions such as:

Lack of food
Extreme temperature
Dry surroundings

Amoeba secretes a protective covering called a cyst.

Inside the cyst:

The nucleus divides repeatedly.
Many daughter amoebae are formed.
When favorable conditions return, the cyst bursts.
Young amoebae are released.

Importance

Helps Amoeba survive harsh conditions.
Ensures rapid increase in population when conditions improve.

Multiple Fission in Plasmodium

Plasmodium, the parasite responsible for malaria, reproduces by multiple fission inside human liver cells and red blood cells.

Process

Parasite enters the host cell.
Nucleus divides repeatedly.
Many daughter parasites are formed.
Host cell bursts.
Daughter parasites infect new cells.

Significance

Rapid multiplication of the parasite.
Causes the spread of malaria infection within the body.

Characteristics of Multiple Fission

Main Features

Asexual mode of reproduction.
Only one parent organism involved.
Produces many offspring at once.
Fast method of reproduction.
Offspring are genetically identical.
Common in unicellular organisms.
Often occurs under unfavorable conditions.

Difference Between Binary Fission and Multiple Fission

Feature	Binary Fission	Multiple Fission
Number of offspring	Two	Many
Nuclear division	Once	Repeatedly
Parent cell division	Into two cells	Into many cells
Examples	Amoeba, Paramecium	Amoeba (cyst stage), Plasmodium
Reproduction speed	Moderate	Very rapid

Advantages of Multiple Fission

Produces many offspring rapidly.
Helps survival during unfavorable conditions.
Increases population quickly.
Requires only one parent organism.
Energy-efficient mode of reproduction.

Examples of Multiple Fission

Organism	Reproduction Method
Amoeba (inside cyst)	Multiple Fission
Plasmodium	Multiple Fission
Some algae	Multiple Fission
Certain protozoans	Multiple Fission

NCERT Summary

Multiple fission is an asexual mode of reproduction.
One parent organism produces many offspring.
The nucleus divides repeatedly before cytoplasmic division.
Amoeba performs multiple fission inside a cyst during unfavorable conditions.
Plasmodium reproduces through multiple fission inside the host body.
It helps organisms multiply rapidly and survive adverse conditions.

Practice Questions

Short Answer Questions

1. What is multiple fission?

Answer: Multiple fission is an asexual reproduction process in which one parent organism divides into many daughter organisms simultaneously.

2. Name two organisms that reproduce by multiple fission.

Answer: Amoeba and Plasmodium.

3. Why does Amoeba form a cyst?

Answer: Amoeba forms a cyst to protect itself during unfavorable environmental conditions.

4. How many offspring are produced in multiple fission?

Answer: Many offspring are produced at the same time.

5. Is multiple fission sexual or asexual reproduction?

Answer: It is asexual reproduction.

Fill in the Blanks

Multiple fission is a form of __________ reproduction.
Answer: asexual
Amoeba forms a protective __________ during unfavorable conditions.
Answer: cyst
In multiple fission, the nucleus divides __________ times.
Answer: many
__________ causes malaria in humans.
Answer: Plasmodium
Multiple fission produces __________ daughter organisms.
Answer: many

MCQs (Multiple Choice Questions)

1. Multiple fission is a type of:

A) Sexual reproduction
B) Asexual reproduction
C) Vegetative propagation
D) Pollination

Answer: B

2. Which organism commonly reproduces by multiple fission?

A) Hydra
B) Yeast
C) Plasmodium
D) Rose

Answer: C

3. During multiple fission, the nucleus divides:

A) Once
B) Twice
C) Three times
D) Repeatedly

Answer: D

4. Amoeba performs multiple fission inside:

A) Bud
B) Seed
C) Cyst
D) Spore

Answer: C

5. Multiple fission produces:

A) Two offspring
B) Four offspring only
C) Many offspring
D) One offspring

Answer: C

6. Which condition triggers cyst formation in Amoeba?

A) Favorable conditions
B) Unfavorable conditions
C) Rainfall
D) High oxygen

Answer: B

7. Plasmodium is responsible for:

A) Dengue
B) Tuberculosis
C) Malaria
D) Cholera

Answer: C

8. Multiple fission helps organisms:

A) Decrease population
B) Reproduce rapidly
C) Stop reproduction
D) Reduce growth

Answer: B

9. How many parents are involved in multiple fission?

A) Two
B) Three
C) Many
D) One

Answer: D

10. The daughter cells produced by multiple fission are generally:

A) Different from parent
B) Genetically identical to parent
C) Larger than parent
D) Unrelated to parent

Answer: B

Quick Revision

✔ Multiple fission is an asexual mode of reproduction.
✔ One parent forms many offspring simultaneously.
✔ Amoeba performs multiple fission inside a cyst.
✔ Plasmodium reproduces by multiple fission in the host body.
✔ Repeated nuclear division occurs before cytoplasmic division.
✔ Helps in rapid multiplication and survival during adverse conditions.