Asexual reproduction in plants

Plants can be cloned by taking cuttings.

New cuttings often experience water stress during the first few weeks.

Which of these practical procedures are used to reduce water stress?

1. Cover cutting with a plastic bag.

2. Remove leaves from cutting.

3. Rooting powder applied to cutting.

A 1, 2 and 3

B Only 1 and 2

C Only 2 and 3

D Only 1

Plants can be cloned artificially by taking cuttings.

Which of the following are important steps when cloning a plant by taking a cutting?

1 Keep it regularly watered. 2 Add rooting hormones to agar jelly. 3 Sterilise a small sample of plant material.

A 1, 2 and 3

B Only 1 and 2

C Only 2 and 3

D Only 1

Plants can be cloned and propagated in horticulture and agriculture.

Describe how artificial clones of plants are produced using micropropagation.

Potato plants can be naturally cloned from tubers.

Many diseases can infect potato plants.

State one disease that can infect potato plants and state the type of pathogen that causes the disease.

The diagram shows a lily plant and a peppermint plant.

Lily plant
Peppermint plant

State the name of structure X and outline how a gardener could produce many cloned plants from structure X.

State the name of structure Y and describe the process by which a new plant can form naturally from structure Y.

A student wrote a method for taking a cutting to clone a plant:

• Select a stem with many flowers and leaves.

• Make a slanting cut in the stem, below some leaves.

• Dip the cut stem in rooting powder.

• Plant the cutting in watered compost.

Describe and explain how the student’s procedure could be improved.

The student investigated the effect of auxin concentration on the growth of shoots.

The student applied different concentrations of auxin to the apical shoot and the lateral shoots.

The student measured the percentage of growth stimulation or inhibition compared to normal.

Normal growth was represented by 0%.

The student’s results are shown in the graph.

Use the graph to estimate the auxin concentration at which inhibition of lateral shoots is 100%.

Auxin concentration =........ mol dm^–3

The student identified a possible anomaly in their results: the data point for the apical shoot receiving 10^–6 mol dm^–3 of auxin.

State what the student could do to determine whether this data point was an anomaly.

Using the graph, describe the conclusions that can be drawn about the role of different auxin concentrations in the control of apical dominance.

Another student plans to investigate the effect of gibberellin concentration on the rate of stem elongation in the pea plant, Pisum sativum.

Suggest appropriate units for the dependent variable in this investigation.

* The student has access to standard laboratory equipment and planting materials.

Outline a method that the student could use to investigate the effect of gibberellin concentration on stem elongation in P. sativum.

In your answer, you should include details of an appropriate statistical test for this investigation.

Additional answer space if required.

A friend of the student had an apple tree in their garden. The friend asked the student if there was a way to ripen the fruit on the apple tree more quickly so that it would be ready to eat within a few days.

The student gave this advice:

‘You should spray the tree with ethene.’

Evaluate whether acting on the student’s advice would produce fruit that was ready to eat within a few days.

Plant cloning is often used by farmers to produce new plants.

A plant that is often cloned by taking cuttings is lavender, Lavandula angustifolia.

A farmer had two fertiliser solutions, solution A and solution B, and wanted to investigate which one to use on lavender plants. In order to ensure the investigation would be valid, two cuttings were needed from the same parent plant.

Describe how to clone a plant by taking a cutting.

Cloning plants is also known as vegetative propagation.

Identify three advantages of vegetative propagation in agriculture.