Growth, repair, cloning and asexual reproduction

Reproduction and inheritance · Cell division, variation and evolution · note 2 of 7

Spec 3.29Download all Cell division, variation and evolution notes (PDF)Download all notes (PDF)6 pages

Growth, repair, cloning and asexual reproductionSpec 3.29

In short

Mitosis occurs during growth, repair, cloning and asexual reproduction, because all of these need new cells that are genetically identical to the parent cell. A multicellular organism grows by making more cells, damaged cells such as cut skin are replaced, and clones and asexual offspring are made with no mixing of genetic information.

Mitosis occurs during growth, repair, cloning and asexual reproduction.

Growth: a multicellular organism grows by making more cells by mitosis. All the new cells are genetically identical, so they have the same instructions.
Repair: damaged or worn-out cells are replaced with new cells made by mitosis, for example when skin is cut.
Cloning: a clone is a group of genetically identical organisms or cells. Clones are made using mitosis, for example plants grown from cuttings.
Asexual reproduction: one parent produces offspring that are genetically identical to it. The offspring are made by mitosis, so there is no mixing of genetic information.

Exam tip:

Asexual reproduction needs only one parent and gives genetically identical offspring. Say both if the question asks you to describe it.

Written and checked against the Edexcel IGCSE Science Double Award (4SD0) specification · Updated October 2026

Frequently asked questions

What is the difference between mitosis and meiosis?

Mitosis produces two diploid cells that are genetically identical to the parent cell and is used for growth, repair, cloning and asexual reproduction. Meiosis produces four haploid gametes, each with half the number of chromosomes and genetically different from each other. In humans, mitosis gives cells with 46 chromosomes and meiosis gives gametes with 23.

How does meiosis create genetic variation?

Meiosis creates genetic variation because the four gametes it makes are genetically different from each other and from the parent cell. Fertilisation is also random, so any sperm can fuse with any egg. This is why brothers and sisters are not identical to each other or to either parent.

How does natural selection lead to evolution?

Natural selection leads to evolution because individuals in a population show genetic variation and compete for resources. Those with characteristics best suited to the environment are more likely to survive and reproduce, passing on their alleles. Over many generations, the proportion of the population with the advantageous alleles increases, so inherited characteristics change.

All 4 questions on Cell division, variation and evolution