Factors that affect cell division

• Availability of energy and materials - Cell division requires energy, enzymes and certain molecules eg nucleotides, proteins. The cell must prepare these before division.

• Stage of life of organism - cell division occurs rapidly during periods of growth and repair in infancy/childhood/early development of animals, following the break of dormancy and during seasonal growth in plants: and after damage when tissue repair is needed.

• Location of cell in organism - mitosis occurs at a higher rate in areas where most growth, repair and replacement of cells is occurring eg skin, hair follicles, bone marrow, root and shoot tips of plants.

• Environmental factors - mitosis and replication involves enzymes so temperature/pH affects rate. Mutagens such as radiation chage rate (rate increases in cancer cells).

• Surface area to volume ratio - greater surface area of cell, greater rate of diffusion into and out of cell. Smaller cell has a greater surface area to volume ratio and greater rate of diffusion than larger cells. cells grow until their size means that the rate of diffusion is too slow to supply cell centre. They then stop and divide into two smaller cells. Plant cells have large fluid filled vacuole in the centre of cell - materials like oxygen quickly diffuse into organelles around vacuole.