Growth in OrganismsEdexcel GCSE Biology: Revision notes
Section 1
How Do Animals Grow?
Growth in animals happens through cell division followed by differentiation: cells divide by mitosis then differentiate; most animal cells lose the ability to differentiate once mature. Growth is mainly an increase in cell number.
Animal growth is mainly an increase in cell number, not cell size.
Section 2
How Do Plants Grow?
Plant growth involves cell division at meristems (root and shoot tips), followed by elongation (cells absorb water and expand), then differentiation. Many plant cells retain the ability to differentiate throughout life.
Growth in plants = cell division at the meristem, then cell elongation.
Section 3
Why Does Cell Differentiation Matter?
Differentiation lets cells develop specific structures suited to function, enabling division of labour in tissues and organs.
Red blood cells lose their nucleus for more haemoglobin space; root hair cells grow long extensions for water uptake.
Section 4
How Do We Monitor Growth?
Percentile charts compare a child's growth (mass/height) against expected ranges for age/sex. A child usually follows one percentile line; crossing lines may indicate a health issue.
Must Know
- Animal growth: cell division + differentiation, mainly increase in cell number.
- Plant growth: cell division, elongation, differentiation.
- Differentiation enables specialised cells and division of labour.
- Percentile charts monitor growth against population norms.
That's the notes covered.
Carry on to the next subtopic.