B3- Cloning

Asexual reproduction

Asexual reproduction produces identical copies. Plants can reproduce asexually, i.e. in the absence of sex cells and fertilisations. Spider plants, strawberry plants and potato plants all reproduce in this way.

Taking cuttings

Plants grown fro cuttings or tissue culture are clones. If a plant has desirable characteristics, it can be reproduced by taking stem, leaf or root cuttings.

1. Select a plant.

2. Take cuttings.

3. Place in damp atmosphere.

4. New genetically identical plants develop.

Commercial Cloning of Plants.

Plants can be cloned to be sold commercially. Advantages include:

• The cloned plants will be genetically identical to the parent, so all the characteristics will be known.
• It is possible to mass-reprodce plants that may be difficult to grow from seeds.

Disadvantages include:

• Any susceptibility to disease, or sensitivity to environmental conditions will affect all the plants.
• The reduction in genetic variation reduces the potential for further selective breeding.

Cloning by tissue culture

Cloned plants can be reproduced by the following method:

1. Select a parent plants with desired characteristics.

2. Scrape off a lot of small pieces of tissue into beakers containing nutrients and hormones. Make sure thn the process is done aseptically (without the presence of bacteria) to avoid the new plants rotting. 

3. Lots of genetically identical plantlets will then grow.

Many older plants are still able to differentiate or specialise, whereas animal cells lose this ability. So, cloning plants is easier than cloning animals.

Cloning Animals

Cloning is an example of asexual reproduction which produces genetically identical copies. Identical twins are naturally occuring clones. 

Animals can be cloned artificially, the most famous being…