Module 5: Commercial uses of plant hormones

Question 1

What is ethene used for commercially?

Answer 1

it plays a crucial role in the ripening of climacteric fruits such as bananas , apples and tomatoes

Question 2

Give the 3 steps involved in controlling fruit ripening using ethene

Answer 2

1)the climacteric fruits are picked when they are unripe
2)in controlled conditions , they are exposed to ethene gas
3)this exposure triggers and synchronises their ongoing ripening process

Question 3

Give the 3 benefits of using ethene to control fruit ripening

Answer 3

-ensures fruits ripen uniformly
-reduces likelihood of fruits being spoiled or damaged during transportation and storage
-helps fruit reach the market in an ideal state for consumption

Question 4

Give 2 commercial uses of auxins for root growth

Answer 4

1)rooting powders which contain auxins stimulate root cell development when applied to plant cuttings which greatly increases the success rate of plant propagation

2)auxins are essential in micro-propagation for mass production of genetically identical plants from tissue samples , to ensure consistency and quality in crops

Question 5

Make 2 points explaining what synthetic auxins are and what they do

Answer 5

they are a class of herbicides which mimic the action of natural auxins but are more exaggerated
-they are used to target and eliminate broad-leaf weeds in agricultural fields

Question 6

Make 3 points about the process of weed killing using synthetic auxins

Answer 6

1)when weeds absorb the synthetic auxins , they undergo rapid and unsustainable growth rates
2)this causes the weeds to die
3)this means nearby narrow leaf crops can continue to grow without competition from weeds

Question 7

Give 3 advantages of using synthetic auxins as weed killers

Answer 7

-they are simple and cheap to produce
-they are of low toxicity to animals
-they are selective so only affect broad-leaf plants (weeds)

Question 8

Give 4 other examples of commercial uses of plant hormones

(one for gibberellins , ethene , auxins and cytokinins)

Answer 8

gibberellins-used to improve size and shape of fruits to enhance their market value and appeal

auxins-used to stimulate fruit development without fertilisation to prevent formation of seeds in fruits

ethene-used to prevent dropping of fruits before harvest to ease the harvesting process

cytokinins-used to extend shelf life of produce by slowing down ageing process