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Micropropagation
In IGCSE biology curriculum, there are five steps in this experiment:
- Small pieces (called explants) are taken from the tips of the stems and the side shoots of the desired plants.
- The explants are sterilised to kill any microorganisms.
- The explants are then grown in vitro – this means they are placed in a petri dish containing a nutrient medium. This medium contains all the nutrients the plant needs to grow. It also contains growth hormones.
- Cells in the explants divide and grow into a small plant.
- The small plants are taken out of the medium, planted in soil and put into glasshouses.
Cloning Adult Mammals
- The nucleus of a sheep’s egg cell is removed, creating an enucleated cell (i.e. a cell without a nucleus).
- A diploid nucleus (with a full set of paired chromosomes) from another sheep is inserted into its place.
- The cell is stimulated by an electric shock so that it starts dividing by mitosis, as if it were a normal fertilised egg.
- The dividing cell is implanted into the uterus of another sheep to develop until it is ready to be born.
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Advantages
There are some ideas you need to remember in IGCSE biology curriculum:
- Useful genetic characteristics can be passed on.
- Makes it possible to produce genetically identical copies of organs for transplantation as they are limited.
- Extinct or endangered species can be repopulated through cloning.
Disadvantages
- Premature aging and early death for the cloned mammal.
- Many, even thousands, of eggs may be required to produce one viable clone, so it is wasteful and expensive.
- If a clone is susceptible to a disease or a change in environment, then all the clones are susceptible as mentioned in IGCSE biology curriculum.
End of this topic!
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Drafted by Gina (Biology)