Tissue cultureSpec 4.9B
Tissue culture is growing new cells or tissues from small pieces of tissue, using sterile conditions and a growth medium.
- Take a small piece of tissue or a few cells from the parent plant.
- Use aseptic technique so that bacteria and fungi do not contaminate the culture.
- Place the tissue on a sterile nutrient medium (such as agar) containing nutrients and growth hormones.
- The cells divide, forming a mass of cells that grow into small plants, which are genetically identical to the parent.
Advantages in plant breeding programmes
- Many identical plants can be produced quickly, from a very small amount of tissue.
- Plants with desirable characteristics, such as those produced by selective breeding or genetic engineering, can be copied exactly.
- Plants can be produced all year round, in a small space.
- Rare plants can be reproduced to help save them.
Advantages in medical research
- Large numbers of identical cells can be grown for research, so results are reliable.
- New drugs can be tested on cultured cells, reducing the need to test on animals or people.
- Cells can be used to study how diseases develop.
Quick check
What is selective breeding?
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Choosing parents with desired characteristics to breed together, and repeating this over many generations.
Name two characteristics selected for in food plants.
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Any two of: disease resistance, larger fruit or grains, better taste, higher yield.
Why can selective breeding be a risk to a population?
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It reduces genetic variation, so a new disease or change could affect all individuals.