Fission

For an organism made of one cell, dividing that cell is the way to reproduce. It needs only one parent, so it is a kind of asexual reproduction. There are two patterns:

• Binary fission: the cell splits into two equal halves. Many bacteria and protozoa do this. In Amoeba the split can happen in any plane. In Leishmania, which causes kala-azar, it happens in a set direction.
• Multiple fission: the cell divides into many daughter cells at the same time. The malaria parasite, Plasmodium, does this.

Yeast is different. It puts out small buds that break off and grow, so it reproduces by budding.

A small example

One bacterium divides into 2. Each of those divides, making 4, and then 8. The new cells are very similar. There are only minor differences between them, from small errors in copying the DNA.

Where marks go

CBSE's 2026-27 sample paper has no question on fission. In a 1-mark question, the marking scheme gives the mark only for the exact answer. "It divides" is not enough if the question wants binary or multiple fission.

The key skill is matching an organism to its way of reproducing. Amoeba and Leishmania go with binary fission, and Plasmodium with multiple fission. See where the marks go in CBSE Science.

About the author

Deepti Sardana

Founder Member & Academic Lead

An IIT alumna (M.Sc., M.Phil.) with over 25 years in teaching, child psychology and learning assessment. As Academic Lead at EduBrahma, she leads the method TRUtesting uses to find where and why a child loses marks.

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