Plant Hormones Practice Questions

Which hormone is produced in the tip of a plant shoot?

• A ethene
• B auxin
• C gibberellin
• D adrenaline

Name the plant hormone that is used to ripen bananas after they have been transported.

Name the plant hormone that is used to make barley seeds germinate more quickly.

Name the plant hormone found in rooting powder.

State the effect of this hormone on the cut shoots.

Give one advantage to the gardener of growing new lavender plants in this way rather than from seed.

Name the response shown by the shoot.

Name the part of the shoot in which the hormone that causes this response is made.

Explain one advantage to the seedling of growing towards the light.

Predict what will happen to seedling A after four days.

Seedling B grew straight upwards. Explain this result.

Seedling D also grew straight upwards. Explain this result.

Name the response shown by the roots.

Explain, in terms of auxin, why the roots grew downwards.

The experiment was repeated with the seeds attached to a clinostat, which slowly rotated them in the dark. Predict the direction of growth of the roots and explain your answer.

Describe the effect of gibberellin concentration on the germination of these barley seeds.

Suggest why increasing the concentration from $10\,\mathrm{mg\,dm^{-3}}$ to $20\,\mathrm{mg\,dm^{-3}}$ made very little difference to the results.

Explain one advantage to the company of treating the barley seeds with gibberellin.

Name the gas used to treat the mangoes before they are sold.

Explain why the fruit is picked while it is still hard and green and why the air in the containers is constantly replaced.

Give one advantage to the supermarket of ripening the fruit with this gas just before it is put on sale.

A wheat field contains many broad-leaved weeds, such as dandelions, growing between the wheat plants. The farmer sprays the whole field with a selective weedkiller that contains a synthetic auxin. Six weeks later the weeds have died, and at harvest the yield of wheat from the field is higher than in previous years.

Explain how spraying this weedkiller increases the yield of wheat.

Describe how the effect of auxin concentration on root growth differs from its effect on shoot growth. Use data from the table in your answer.

A whole bean seedling is laid on its side in a dark cupboard. After two days the root has grown downwards and the shoot has grown upwards. Use the data in the table to help you explain these growth responses.