Uses Of Plant Hormones

Question 1

Auxin: (Selective Weedkiller)

• use
• how it works
• advantages

Answer 1

• Selective Weedkiller
• Makes some plants grow uncontrollably and kills them
  Artificial auxins= only kill broad leaved plants (eg: dandelions) and disrupt their growth patterns
• It can kill weeds in a wheat field, without affecting the crops

Question 2

Auxin: (Rooting Powders)

• use
• how it works
• advantages

Answer 2

• Rooting Powders
• Makes Plant cuttings develop roots quickly
• Large numbers of identical plants can be grown quickly (compared to seeds)

Question 3

Gibberellins: (Germination)

• use
• how it works
• advantage

Answer 3

• Germination
• Naturally released inside seed to cause germination
• Plant growers can make seeds germinate without the periods of dark/cold, before they usually would

Question 4

Gibberellins: (Seedless fruit)

• use
• how it works
• advantage

Answer 4

• Seedless fruit
• Allows some fruit to produce fruit without pollination (no seeds)
• Greater consumer appeal of seedless fruit + they can grow bigger

Question 5

Ethene:

• use
• how it works
• advantage

Answer 5

• Ripening
• Unripe fruit are exposed to ethene, which causes them to ripen
• Fruit can be more easily transported when unripe + stored in cold storage for longer + ripened when ready in shops

Question 6

How can an experiment with gibberellins and seeds be improved?

Answer 6

Using more than one seed in each concentration of gibberellins.

Question 7

What is photoperiodism?

Answer 7

A response of an organism to the number of daylight hours in a day.

Question 8

What happens to plant species in the winter (live/die)?

What happens after this in spring?

Answer 8

• Many species of plant die in winter but their seeds survive
• In spring- the days are longer and the seeds can germinate
• Gibberellins override this process