6.2.1 Cloning And Biotechnology

Question 1

Define cloning

Answer 1

The process of producing genetically identical cells or organisms from cells of an existing organism

Question 2

What is vegetative propagation?

Answer 2

The production of plant clones where this production comes from non-reproductive tissues, e.g. roots, leaves and stems - asexual reproduction

Question 3

Give 5 examples of vegetative propagation?

Answer 3

1. Rhizomes
2. Stolons/ Runners
3. Suckers
4. Tubers
5. Bulbs

Question 4

What are rhizomes?

Answer 4

Stem structures that grow horizontally underground away from the parent plant. They have ‘nodes’ from which new shoots and roots can develop. Bamboo uses rhizomes.

Question 5

What are Stolons/Runners?

Answer 5

Main difference from rhizomes is that these grow above ground, on surface of main soil - new shoots and roots can either develop from nodes or form at the end of the stolen e.g. a plant that uses stolons in the strawberry

Question 6

What are Suckers?

Answer 6

Shoots that grow from sucker buds (undeveloped shoots) present on the shallow roots of a parent plant
E.g. a Elm tree

Question 7

What is a tuber?

Answer 7

Large underground plant structures that act as a food store for the plant - they’re covered in ‘eyes’. Each eye is able to sprout and form a new plant
E.g. a potato

Question 8

What are bulbs?

Answer 8

These are underground food stores used by some plants - new bulbs are able to develop from an original bulb + form new individual plants
E.g. Onions

Question 9

Name 3 ways in which vegetative propagation in horticulture an agriculture?

Answer 9

1. Cuttings
2. Grafting - joining the shoot of one plant to the growing stem and root of another plant
3. Layering - bending a stem of a growing plant downwards so it enters the soil and grows into a new plant

Question 10

How do farmers use cloning methods?

Answer 10

To get uniform crops as clones are genetically identical, any beneficial characteristics will be present in each crop plant.

Question 11

Method to produce clones from cuttings

Answer 11

1. Use a scalpel or sharp secateurs to take a cutting, between 5 cm and 10 cm long, from the end of a stem of your parent plant
2. Remove the leaves from the lower end of your cutting (if there are any), leaving just one at the tip
3. Dip the lower end of the cutting in rooting powder, which contains hormones that induce root formation
4. Then plant your cutting in a pot containing a suitable growth medium (e.g. well drained compost)
5. Provide your cutting with a warm and moist environment by either covering the whole pot with a plastic bag or by putting it is a propagator (a specialised piece of kit that provides these conditions)
6. When your cutting has formed its own roots and is strong enough, you can plant it elsewhere to continue growing