22.2 Artificial cloning in plants

Question 1

Give three ways to artificially clone plants. (3 marks)

Answer 1

Take cuttings
Grafting
Tissue centre

Question 2

How is a cutting taken to clone plants? (3 marks)

Answer 2

Cut a section of stem between nodes
Use rooting powder on the stump (contains hormones to encourage growth)
Reduce number of leaves on the cutting, water well

Question 3

What is grafting? (1 mark)

Answer 3

When a shoot section of a woody stem is joined to a root stock.

Question 4

What is a scion? (1 mark)

Answer 4

The piece of organism that is being propagated, in grafting.

Question 5

What is a rootstock? (1 mark)

Answer 5

Piece of organism that will provide correct vigour growth, in grafting.

Question 6

Describe how grafting works. (2 marks)

Answer 6

Scion and rootstock are put together and bound with grafting tape–> tissues join.

Question 7

What is a tissue culture? (1 mark)

Answer 7

Growing new tissues, organs, or plants from certain tissues cut from sample plants.

Question 8

What is micropropagation? (1 mark)

Answer 8

Growing large numbers of plants from meristem tissue taken from a sample plant

Question 9

When is micropropagation used? (2 marks)

Answer 9

When a plant:
Doesn’t produce many seeds
Is very rare
Is GM/selectively bred
Doesn’t respond well to natural cloning

Question 10

Explain how micropropagation is used. (6 marks)

Answer 10

1.Cells taken from shoot (explant)
2.Cells sterilised before being put in nutrient medium
3.Explant placed on sterile growth medium
4.Forms a callus culture- divide to produce lots of small clumps of cells
5.Single cells removed from callus and transferred to a new agar medium- plantlets (shoots) grow
6.Transferred to compost