Flashcards in Cloning Deck (18):
What asexual production is sometimes called vegetative reproduction?
Vegetative reproduction is in flowering plants, parts of the root, leaf or stem can grow into new plants.
What does vegetative reproduction produce?
Vegetative reproduction produces new plants which are genetically identical (clones) to the parent plant.
Why is vegetative reproduction useful to gardeners?
It is useful to gardeners and farmers who want stocks of plants with preferred characteristics such as disease resistance, fruit colour, flower shape etc.
What is the step-by-step method of making artificial plants?
- Take a healthy plant and cut off a small length of the stem.
- Dip the end of the cut stem into hormone rooting power.
- Put the stem into a flowerpot full of damp compost.
- Cover the pot with a plastic bag to keep it moist
- This will then grow into a new plant.
What is tissue culture?
Tissue culture is a process that involves cutting small pieces of tissue from the parent that is to be cloned.
What are embryo transplants?
- Donor eggs are taken from female animals and fertilised in the laboratory.
- Each embryo that forms is split up into its separate cells.
- Some of the separated cells are transplanted into the womb of a host mother, where they develop into identical embryos.
- The host mother later gives birth to several genetically incidental youngsters. They are clones.
What and when was the first animal cloned?
In 1996 the first animal was cloned. This animal was a sheep named Dolly.
What are the stages in the production of a cloned sheep?
- There are two sheep with donor eggs.
- Sheep A has it's nucleus removed (enucleated)
- Sheep B has it's diploid nucleus removed from cell body and inserted into the enucleated egg cell.
- Electrical stimulation of the diploid nucleus is used to divide by mitosis.
- Diploid cell divides by mitosis and forms an embryo.
- Embryo is implanted into surrogate sheep.
- Lamb is born.
Why are cows being cloned using embryo transplants?
Cows are being cloned using embryo transplants because it might produce cows with a high milk yield.
What are the advantages of cloning?
- All the new plants are genetically identical – they will all have the desired characteristics.
- Organisms that are difficult or slow to breed normally can be reproduced quickly. Some plant varieties do not produce seeds, others have seeds that are dormant for long periods.
- Cloning allows scientists to produce animals with desirable characteristics quickly and reliably.
- It helps build up population of rare animals which might otherwise be threatened by extinction.
What are the disadvantages of cloning?
- If a clone is susceptible to disease or changes in environment, then all the clones will be susceptible.
- It will lead to less variation, and less opportunity to create new varieties in the future.
What can stem cells possibly be used for?
- Making new brain cells to treat people with
- Parkinson's disease
- Rebuilding bones and cartilage
- Repairing damaged immune systems
- Making replacement heart valves
What are embryonic stem cells?
Embryonic stem cells are the cells on the inside of an embryo.
What happens as cells mature?
As cells mature, they can no longer differentiate.
What is stem cell therapy?
If stem cells can be made to multiply and differentiate, we would have an unlimited supply of different types of cells, which could be transplanted into people whose tissues are damaged.
What are the risks of using embryonic stem cells?
- Rejection of the embryonic stem cells.
- The possibility that adult stem cells may carry genetic mutations for disease or may become defective.
- The appearance of side-effects and complications in the recipient; stem cell therapy may trigger adverse immune responses or the development of cancers.
- Claming of the effectiveness of the therapies and treaments offered are sometimes from unregulated sources, whose treatment may be dangerous.
What are the steps of therapeutic cloning?
- Nucleus taken out of a human egg cell
- Nucleus from a patient's cell put into the egg cell
- Egg cell stimulated to develop into an embryo
- Stem cells taken from the embryo
- Stem cells grown in a container of warm nutrients
- Stem cells treated to develop into required cell types