Uses Of Plant Hormones

Question 1

Auxin (selective weed killer)

• use
• how it works
• advantages

Answer 1

• selective weed killer
• 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 (Seedless fruit)

• use
• how it works
• advantages

Answer 3

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

Question 4

Gibberellins (germination)

• use
• how it works
• advantages

Answer 4

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

Question 5

Ethene:

• use
• how it works
• advantages

Answer 5

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