Cloning (T5)

Question 1

What is cloning?

Answer 1

Any procedure that produces genetically identical offspring.

Question 2

Describe two ways in which plants can increase their numbers by asexual reproduction..

Answer 2

A potato plant can produce many tubers, each of which can grow into a new plant.

Strawberry plants and spider plants produce long stems with tiny plants on the end. These runner can produce several new plants from one parent.

Question 3

Describe how you can artificially produce new plants using the runners from a strawberry plant and then waiting for the runner to develop new roots and leaves

Answer 3

• get a runner, leave it attached to the mother plant and stick it in some compost
• you will have a new strawberry plant however it will be genetically identical to the mother plant
• for variety, the new strawberry plant would have to come from planting the seeds on the outside of the flesh

Question 4

Describe the stages in cloning a plant..

Answer 4

• a side shoot from a plant is removed
• the side shoot is dipped in rooting powder to encourage root formation
• the shoot is planted in compost
• the planted shoot is placed under glass
• the plant cuttings contain identical genes as they are all from the same parent plant
• as the cuttings grow they form new cells by mitosis and hence these cuttings develop into genetically identical plants - clones!

Question 5

When cloning plant, why is the removed / planted shoot put under glass?

Answer 5

This creates a ‘mini-greenhouse’ which provides a warm environment to speed up growth.

It also creates a humid environment to reduce water loss from the leaves of the cuttings.

Question 6

What are some advantages of cloning?

Answer 6

All the new plants are genetically identical therefore all the desired characteristics you were looking for would be there.

It is much faster than breeding.

Question 7

Give some examples when cloning is required in plants..

Answer 7

In some varieties, such as the petunia derivative, the surfuna do not produce seeds and therefore the only way they can be reproduced is through vegetative propagation.

This is a type of cloning.

Some other plants have seeds that are dormant for long periods or need smoke from a fire to make them germinate.

Question 8

Give some disadvantages to cloning..

Answer 8

If a clone is susceptible to disease or changes in environment then all clones will be more likely to be affected.

It leads to less variation, and therefore less opportunities to create new varieties in the future, as many clones are infertile.