Cloning and biotechnology
Natural cloning
Vegetative propagation
- Flowering plants
- From stem. Leaf, bud, root (vegetative organs of the plant which are not used in
sexual reproduction)
In horticulture:
- Increase numbers of plants cheaply
- All plants have same genetic characteristics from the parent plant = all will be
good quality
, 2
Plant cuttings
, 3
Artificial cloning
Tissue culture
Micropropagation: increase numbers of genetically identical offsprings from a single
parent plant
When the desirable plant:
- Has no seeds
- Does not respond to natural cloning
- Rare
- Genetic engineering/Selective breeding is difficult
- Pathogen-free
i. Small sample of meristem tissue from shoot tips (totipotent) =
virus-free
ii. Is sterilised in bleach/ethanol = explant
iii. Explant in sterile culture growth with hormones = mitosis
iv. Cells divide = callus (mass of undifferentiated cells)
v. Callus divided up = clumps transferred to its own culture medium =
genetically identical plantlets = potted into compost and planted
out to grow
For
● Rapid production with known genetic make-up = good crops
● Disease-free products
● Seedless and sterile for consumer tastes
● Can grow plants which grow naturally infertile or difficult to breed from seed
● Can grow rare plants
Natural cloning
Vegetative propagation
- Flowering plants
- From stem. Leaf, bud, root (vegetative organs of the plant which are not used in
sexual reproduction)
In horticulture:
- Increase numbers of plants cheaply
- All plants have same genetic characteristics from the parent plant = all will be
good quality
, 2
Plant cuttings
, 3
Artificial cloning
Tissue culture
Micropropagation: increase numbers of genetically identical offsprings from a single
parent plant
When the desirable plant:
- Has no seeds
- Does not respond to natural cloning
- Rare
- Genetic engineering/Selective breeding is difficult
- Pathogen-free
i. Small sample of meristem tissue from shoot tips (totipotent) =
virus-free
ii. Is sterilised in bleach/ethanol = explant
iii. Explant in sterile culture growth with hormones = mitosis
iv. Cells divide = callus (mass of undifferentiated cells)
v. Callus divided up = clumps transferred to its own culture medium =
genetically identical plantlets = potted into compost and planted
out to grow
For
● Rapid production with known genetic make-up = good crops
● Disease-free products
● Seedless and sterile for consumer tastes
● Can grow plants which grow naturally infertile or difficult to breed from seed
● Can grow rare plants
