Gibberellins In Stems, Leaves, And Fruits.

Question 1

What’s the role of gibberellins?

Answer 1

Break the dormancy of seeds.

Question 2

How does GA3 break the dormancy of seed?

Answer 2

1- water softens the seed coat and stimulates the plant embryo to produce GA3
2-GA3 triggers synthesis of the enzyme amylase
3- amylase catlyzes the break down of starch to supply energy for sprouting.

Question 3

What happens if we sprayed GA3 on dwarf plant?

Answer 3

It stimulated cell elongation and they grew to normal height.

Question 4

What happens if we sprayed GA3 on normal plants?

Answer 4

It stimulates cell elongation and they grew into giant plants

Question 5

How would the grapes look like WITHOUT GA3?

Answer 5

1 - seedless grapes with short branches
2 - fewer fruit clusters.
3 - small grapes

Question 6

How would the grapes look like with GA3?

Answer 6

1- fruits are maturing instead of during seed development
2- larger grapes
3- bunching further apart on longer stem

Question 7

The effect of GA3 on lettuces and apples?

Answer 7

• It helps break down dormancy of the seed, eliminating the need for light and helping them to germinate.

Question 8

Describe the role of the abscisic acid and gibberellins hormones in the germination of the seeds.

Answer 8

The two hormones work in opposite ways (antagonistic): abscisic acid aids dormancy in the seeds while gibberellins break down dormancy and stimulate their germination.