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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.
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!
Drafted by Gina (Biology)