5 Cloning PAPER 2 Flashcards
Why is micro propagation (tissue culture) used?
to produce large number of genetically identical plants
Useful for plants that are difficult to propagate by seeds or cutting
Describe the method of micropropagation
explant is cut from desired plant. Sterilised and placed onto nutrient gel, where it grows into callus (small ball of cells)
Small groups of cells are taken from callus
Plant hormones used to stimulate shoot and root growth
Small bundles of cells grow into individual cloned plants
Transfer new plants to soil
What are gene banks?
seeds of all different varieties are kept, in case breeders may want to use them in years to come
How are plants cloned using cuttings?
cut small length of stem or leaf from parent plant
base of cutting dipped in rooting powder
once roots grow, cutting can be planted into soil
Who was the first cloned mammal?
Dolly the sheep
How are cloned mammals formed?
Take body cell (diploid) from sheep A
(extract DNA)
Take egg cell from sheep B
(nucleus removed)
DNA from Sheep A fused with (enucleated) egg cell from Sheep B (electric shock helps process)
Fused cell develops into embryo (divides by mitosis) which is placed in uterus of foster mother
Lamb is clone of Sheep A
What can cloning mammals also be used to help?
save species from extinction
How can pigs be genetically modified?
Pigs could be genetically modified to have human antigens on cell membranes allowing pig organs to be transplanted into humans as it would reduce immune response against the organ and risk of injection
What are the complications of cloning human body parts?
ethical considerations
xenotransplantation could lead to viruses being transferred between species
How can goats be genetically engineered?
GE goats or similar animals to produce human proteins, e.g. antibodies, in their milk.
GM goats could be cloned to increase population
Proteins collected from milk and used to treat patients with weak immune systems, such as cancer or HIV patients, or other health conditions
