Cloning and Biotechnology Flashcards
What is asexual reproduction?
A form of cloning that results in offspring produced by mitosis and known as clones.
What is a clone?
An organism that is genetically identical to the parent organism and to other clones.
What is another name for vegetative propagation?
Natural cloning
What happens in vegetative propagation?
A structure forms which develops into a fully differentiated plant which is still genetically identical to the parent that eventually become independent of the parent plant.
Where can the new plant be propagated from?
The stem, leaf, bud or root of the parent depending on the type of parent plant.
What allows plants to survive adverse conditions during vegetative propagation?
Perennating organs.
What are perennating organs?
Organs that contain stored food from photosynthesis and can remain dormant in soil. They are used as a means for asexual reproduction as well as a way of surviving between growth seasons.
Give examples of where natural plant cloning occurs.
Bulbs in daffodils.
Runners in strawberry plants.
Rhizomes in marram grass.
Stem tubers in potatoes.
How do bulbs work?
Leaf bases swell with stored food from photosynthesis, buds form from within and develop into roots and shoots during the next growth season.
How do runners work?
A second stem grows away from the parent plant and roots grow where the runner touches the ground. A new plant will grow here and the runner will eventually become independent.
How do rhizomes work?
A rhizome is a specialised horizontal stem running underground often swollen with stored foods, buds form and new roots develop and eventually this becomes the independent clone.
How do stem tubers work?
The tip of an underground stem becomes swollen with stored food to form a tuber or storage organ. Buds on the storage organ develop to produce new shoots.
How is natural plant cloning used in horticulture?
Farmers and gardeners exploit natural plant cloning to produce new plants.
What are some cheap ways of increasing plant numbers?
Splitting up the bulbs.
Removing young plants from runners.
Cutting up rhizomes.
Taking cutlets of plants.
What are cutlets?
Short sections of stems are taken and planted either directly into the ground or in pots.
What are the advantages of using cutlets?
It is much faster.
Guarantees the quality of the plants.
What is the main disadvantage using cutlets?
There is no genetic variation in the offspring therefore a new pest or disease or a sudden change in climate would wipe put this whole population.
Give an example of some prominent food crops that are propagated by cloning.
Bananas Sugar Cane Sweet Potatoes Cassava Coffee Tea
Explain the process of cloning sugar cane.
1) Short lengths of around 30cm long cane with 3 nodes are cut.
2) They are buried in a clear field in shallow trenches and covered with a thin layer of soil.
3) Per hectare between 10 and 25000 lengths are planted.
What are totipotent cells?
They can differentiate into all of the different types of cells in the plant.
What is micropropagation?
The process of making large numbers of genetically identical offspring from a single parent plant using tissue culture techniques.
In what situations are micropropagation used?
When the plant does not:
If the plant does not produce seeds.
If the plant does not respond well to natural cloning.
If the plant is rare.
If the plant has been genetically modified or selectively bred in the past with difficulty.
