Growth
Growth is a permanent increase in size and dry mass 1.
Permanent, Not Temporary
Both words matter. A seedling that takes up water, or an animal that drinks, becomes larger and heavier without having grown — that increase is reversible and mostly water. Dry mass is measured after the water is removed, so a permanent rise in dry mass is the reliable proof of growth.
How Growth Happens
| Mechanism | Contribution |
|---|---|
| Cell division (mitosis) | Increases cell number; produces genetically identical cells |
| Cell enlargement | Vacuolation and elongation increase cell volume |
| Cell specialisation | Cells differentiate into specialised types with specific functions |
Stem cells are unspecialised cells that divide by mitosis, and mitosis has roles in growth, repair of damaged tissues, replacement of cells and asexual reproduction 1. Growth therefore needs raw materials and energy: nutrition supplies both, and respiration releases the energy for protein synthesis and cell division.
Measuring Growth
Plotting dry mass (or height, or leaf area) against time gives a growth curve. Plants continue to grow throughout life from regions of dividing cells near their tips, while most animals stop growing once mature — human growth slows markedly after puberty.
Related
- Living Thing - Entity carrying out all seven life processes.
- Organism - Individual living thing, unicellular or multicellular.
- Nutrition - Supplies materials and energy for growth.
- Reproduction - Mitosis also underlies asexual reproduction.
- Sensitivity - Responses such as tropisms are growth movements.
- Biology - Cambridge IGCSE life-science area.
Footnotes
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Cambridge IGCSE Biology 0610 syllabus for examination in 2026, 2027 and 2028 - Growth as permanent increase in size and dry mass (1.1d), mitosis and stem cells (17.2). ↩ ↩2