Uses of plant hormones

Question 1

Name 3 plant hormones

Answer 1

auxins, gibberellins, ethene (gas)

Question 2

What are selective weedkillers and how do they work?

Answer 2

• contain auxins
• weed plants compete with crops for water/minerals
• weeds are broad leaved plants, crops are narrow leaf
• broad leaved plants absorb more auxin, causing them to grow quickly and die

Question 3

What is rooting powder and how does it work?

Answer 3

• contains auxins
• gardeners take cuttings of plants to grow into new ones
• they dip the stalk end into rooting powder
• the auxins cause the stalk to produce roots quickly
• this makes the plant grow faster

Question 4

What do gibberellins do?

Answer 4

• stimulate germination of seeds, which increases crop yields
• stimulate flower and fruit production
• stimulate stem elongation
• seedless/bigger fruit

Question 5

How can plant hormones be used to produce seedless and bigger fruit?

Answer 5

• gibberellins sprayed onto flowers stop seeds developing in the fruit
• can also make the fruit larger
• makes fruit more valuable