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Slide 2: Forced manipulation of organisms to produce fertile offspring which will be genetically
identical to the parent
Slide 3: The three main types of vegetative propagation are grafting, tissue cultures and taking
cuttings, because they're the easiest, most successful and are more versatile in their application.
Tissue cultures are the most common form of artificial propagation.
Types of propagation by plant
Cuttings: Begonias, Pineapples. Layering, Rubber Tree. Separation/Division: Irises, Lilies. Grafting:
Roses, Walnuts, Apples, and Apricots.
Tissue cultures are used for micro propagation. A small piece of tissue is taken from the plant which is
to be cloned. The tissue is known as the explant. The explant is placed on growth medium, where
cells in the tissue divide, but don't differentiate. Forming a cellular mass of undifferentiated cells-
known as a callus. After a few weeks single callus cells are put onto their own growth medium
where they're treated with hormones to stimulate shoot growth. The developing shoots are then
transferred to another growth medium and are treated with more hormones, which encourage
root growth. The plants are left in the greenhouse until they acclimatise and mature enough to be
able to grow in external conditions.
Advantages Quicker than natural processes, e.g. helpful bacteria used can multiple every twenty
Offspring are genetically identical so can be manipulated to carry specific advantageous traits.
Only one parent is needed which again, saves time and is less hit and miss w/ pollination occurring.
Agriculturists and horticulturists can produce crops such as bananas, sugar cane and potatoes that
don't produce viable seed more easily.
Parent plants that are disease free, will produce offspring with no underlying disease too, cheaper
more efficient, less waste and tissue culture method means that organisms can be specifically
designed to be disease free and sometimes resistant.
Artificial propagation is quicker than natural mechanisms, so organisms can rapidly colonise an area
that they are required to.
Disadvantages There is no genetic variation to allow for natural selection or potentially
advantageous mutations that could results in a more resilient and more fertile organism.
Lots of plants in one place, same nutrients, light, space, water- will become deficient supplies in the
Lack of versatility because all organisms are genetically identical it decreases the chance that they
can adapt to environmental changes.