B1 - Cloning Flashcards
Describe how cuttings work
Gardeners can take cuttings from good parent plants and plant them to produce genetically indentical copies
This can be done quickly and cheaply
What are the 2 ways that plants can be cloned?
Cuttings
Tissue culture
Describe how tissue culturing works
A few plant cells are put into a growth medium with hormones and they grow into clones of the parent plant
This is very quick and can be done in very little space and be grown all year
What are the 2 ways of cloning animals?
Embryo transplants
Adult cell cloning
Describe how embryo transplanting works
Sperm is taken from a good father and egg cells are taken from a good mother
The sperm is used to artificially fertilise an egg cell
The embryo is split many times to form many clones before the cells become specialised
These cloned embryos will be implanted into lots of other cows where they will be grow into offspring that will be clones of each other
Describe how adult cell cloning works
An unfertilised egg is taken and the nucleus (genetic material) is removed
A complete set of chromosomes is taken from an adult body cell
The egg cell is stimulated by an electric shock so that it divides like a normal embryo
It is then implanted into an adult female to grow into a clone of the original adult body cell
What are the 2 advantages of cloning?
Can lead to a greater understanding of the development of the embryo
Could help preserve endangered species
What are the 3 issues of cloning?
Leads to a reduced gene pool (fewer different alleles in a population)
Cloned animals are not usually as healthy as normal ones
People worry that humans will be cloned in the future and this would lead to many serious unsuccessful attempts
What is genetic engineering?
Altering an organisms genes in order to change its characteristics
Describe how genetic engineering is done
A useful gene is cut from one organism’s chromosome using enzymes
Enzymes are then used to cut another organism’s chromosome and then to insert the useful gene
What are the 3 main ways that genetic engineering is used?
Genetically modified (GM) crops are engineered to make them resistant to viruses, insects and herbicides
Sheep have been genetically engineered to produce substances like drugs in their milk
Genetic disorders like cystic fibrosis are caused by faulty genes. Scientists are trying to treat these disorders by inserting working genes into sufferers (gene therapy)
What are the 4 advantages of GM crops?
Can increase yield of the crop making more food
Less work for the farmer
Crops can be engineered to produce nutrients that are required by people in some developing countries
GM crops are being grown elsewhere in the world without any problems already
What are the 3 disadvantages of GM crops?
GM crops can reduce the number of weeds and flowers which also has many knock-on effects that reduce biodiversity
People could be harmed by eating GM crop
The transplanted genes could be picked by other unwanted species of plants like weeds
