Tissue culture makes genetically identical cells

1. Tissue culture is the growth of cells or small pieces of tissue on a sterile nutrient medium so that many genetically identical cells or organisms are produced.
2. For plants, remove a small piece of tissue called an explant from a parent with the desired characteristics.
3. Sterilise the explant and equipment to prevent bacteria or fungi from outcompeting the plant cells.
4. Place the explant on sterile agar containing minerals, sugar and plant growth regulators.
5. Keep the culture under controlled light and temperature until cells divide by mitosis and form a mass of cells.
6. Transfer small groups of cells to media with suitable hormone balances so shoots and roots develop, then move plantlets to compost and acclimatise them gradually.

Clones give consistency and rapid production

1. A clone is an organism or cell that is genetically identical to another because it was produced from one parent by mitosis.
2. A small sample can produce many plants quickly, at any time of year and in little space.
3. Rare plants can be conserved and crop varieties with high yield or disease resistance can be copied without losing their allele combination.
4. Genetically identical cells allow medical researchers to test treatments while reducing genetic variation between samples.
5. All clones may share the same susceptibility to a pathogen, and mutation or contamination can affect many cultures.