Cloning

Question 1

Describe the process of micropropagation

Answer 1

• a number of explants are taken from the parent plant
• the plants are sterilised to kill any micro-organisms
• the explants are then grown in vitro (in a Petri dish containing a nutrient medium)
• the medium also contains growth hormones
• the cells divide to form a mass of cells called a callus
• the calluses are moved into soil to grow into many identical copies of the parent plant
• the plants must be provided with light, water and CO2

Question 2

Describe the stages in producing cloned mammals

Answer 2

EXAMPLE: DOLLY THE SHEEP

• take an egg cell from the ovary of sheep A
• remove the nucleus to create an enucleated egg cell
• take a cell from the udder sheep B and remove the nucleus
• the egg cell from sheep A and the nucleus from sheep B are fused together by an electric shock
• now an egg has been made that contains the DNA from sheep B
• cell division happens several time by mitosis until an embryo is formed
• the embryo is implanted into the uterus of sheep A
• the sheep will be born and will be a clone of sheep B