B11.10 - Using Plant Hormones

Question 1

What are the three uses of auxins?

Answer 1

Killing weeds, growing from cuttings with root powder, growing cells in tissue culture

Question 2

How does auxin used to kill weeds?

Answer 2

Most weeds have broad leaves unlike grasses and cereals that have narrow leaves. Selective weedkillers will on,y affect broad-leaved pants, disrupting their growth patterns, killing them

Question 3

How can auxins be used to grow from cuttings with rooting powder?

Answer 3

A cutting is a part of a plant that has been cut off. If rooting powder containing auxins is added cuttings will produce roots rapidly and start growing as new plants, enabling lost of clones to be produced wuick

Question 4

How do auxins help with growing cells in tissue culture?

Answer 4

Tissue culture can be used to grow clones of a plant from a few cells, hormones such as auxin are added to the growth medium stimulating cells to divide and form roots + shoots

Question 5

What is giberellin?

Answer 5

Gibberellin is a plant hormone that stimulates seed germination, stem growth and flowering

Question 6

What 3 things can gibberellin be used for?

Answer 6

Controlling dormancy, inducing flowering, growing larger fruit

Question 7

Why is gibberellin used to grow larger fruit useful?

Answer 7

Seedless varieties of fruit often do not grow as large as seeded fruit, but gibberellin makes them

Question 8

How can gibberellin be used to control dormancy?

Answer 8

Lots of seeds won’t germinate until they have been through certain conditions (e.g. cold). Seeds treated with gibberellin will make them germinate at all times of year

Question 9

Why is gibberellin used to induce flowering?

Answer 9

Some plants require certain conditions for flowering such as long days or low temperatures

Question 10

What is ethene?

Answer 10

Ethan is a gas produced by ageing parts of a plant. It influences the growth of the plant by controlling cell division and stimulates enzymes causing the fruits to ripen