T5 plant hormones Flashcards Preview

aqa gcse biology free > T5 plant hormones > Flashcards

Flashcards in T5 plant hormones Deck (12)
Loading flashcards...
1
Q

what is tropism

A

response of a plant to a specific stimulus

2
Q

what is phototropism

A

response of a plant’s shoot or root to light

3
Q

what is gravitropism

A

response of a plant’s shoot or root to gravity

4
Q

what is auxin

A

hormone which controls the growth of a plant’s shoots and roots

when auxin is unevenly distributed in
a growing plant, the rate of growth will also be unequal

5
Q

how do plant shoots show positive phototropism

A

one side of the shoot is in the light, causing auxin to move to the shaded side

at the shaded side, the cells are stimulated to grow - the shoot bends towards the light

as a result, photosynthesis can occur at a faster rate

6
Q

how do plant shoots show negative gravitropism

A

In a horizontal shoot, auxin accumulates in the lower side due to gravity.

Cells on the lower side of shoot grow more, causing the shoot to bend away from the direction of gravity.

As a result, more light is usually available for photosynthesis.

7
Q

how do plant roots show positive gravitropism

A

In a horizontal root, auxin accumulates in the lower side, causing cells to grow less.

The root bends in the direction of gravity

As a result, more water and nutrients are
available to the plant roots.

8
Q

what are gibberellins

A

type of plant hormone involved in seed germination

9
Q

what is ethene

A

type of plant hormone involved in cell division and ripening

10
Q

what are the uses of auxins

A

weedkillers - causes cells to grow at a rapid rate, causing plant death

rooting powder - causes new plant to grow very quickly

tissue culture - promotes growth of roots and shoots

11
Q

uses of ethene

A

control of food ripening in the food industry - allows fruit to be ripened just before they are sold

12
Q

uses of gibberellins

A

termination of seed dormancy

promotion of flowering

increase of fruit size