Cells and specialisation

All living things are made up of tiny, microscopic units which we call cells.

Animal and plant cells

Animal cells

Animal cells are made up of many different elements:

NucleusControl centre of the cell. It contains the cell’s genetic information arranged in chromosomes.
ChromosomesThreadlike structure found in the nucleus. Made of DNA which contains the genetic information of the cell.
CytoplasmChemical reactions take place here.
MitochondriaSite of cell respiration. Very abundant in cells that need a lot of energy (e.g. muscle cells).
Cell membraneA selectively permeable boundary surrounding the cell which allows some substances to enter and leave the cell while preventing others.
Nuclear membraneSurrounds nucleus.

Plant cells

Plant cells contain all of the elements which make up animal cells, but they also include:

Cellulose cell wall A rigid structure outside the cell membrane that provides support.
Large permanent vacuole Contains cell sap and when full pushes the cell membrane against the cell wall, providing support.
Chloroplasts Contain chlorophyll, a green pigment that traps light for photosynthesis.