5 homeostasis - plant hormones

Question 1

AUXIN plant hormone

Answer 1

• grows on TIPS of shoots and roots
• controls the growth of a plant in response to light and gravity

Question 2

what does the plant hormone AUXIN control

Answer 2

growth of a plant in response to
- light (PHOTOTROPISM)
- gravity (GRAVITROPISM)

Question 3

what happens to plants when the shoots grow TOWARDS LIGHT

Answer 3

1. when the shoot tip is exposed to light, more auxin gathers on the SHADED side
2. so cells elongate longer on the shaded side so the shoot bends towards the light.

Question 4

what happens when SHOOTS grow side ways and bend AWAY FROM GRAVITY

Answer 4

• SHOOT growing side ways, more auxin on lower side
• lower side grows faster and shoot bends upwards

Question 5

what happens when ROOTS grow TOWARDS GRAVITY

Answer 5

• ROOT growing sideways has more auxin on lower side
• but roots extra auxin STOPS growth
• top of root will elongate faster and root will bend downwards

Question 6

investigate plant responses PRACTICLE

Answer 6

• seeds in petri dish with damp cotton wool
• 3 Dif lights from all dif directions
• in a week observe their responses

Question 7

Commerical uses of AUXIN (plant hormone)

Answer 7

• killing weeds
• rooting powder (auxin in this which makes cutting from plants grow)
• growing cells in tissue culture

Question 8

what and Commerical uses of GIBBERELLIN (plant hormone)

Answer 8

• controlling dormancy (grow things at all times of year)
• inducing flowering ( grow bigger flowers in normal conditions)
• growing larger fruit

Question 9

what and Commerical uses of ETHENE (plant hormone)

Answer 9

gas produced by ageing parts of a plant and influences the growth by controlling cell division and stimulating enzyme that cause fruit to ripen

• speed up the ripening of fruit