Homeostatis-plants

Question 1

Tropism

Answer 1

Plants respond via growth to stimuli
-Positive=toward
-Negative=away

Question 2

Phototropism in shoots

Answer 2

1. shoot produces IAA, causing cell elongation
2. IAA diffuses to the shaded side of the shoot, so high conc of IAA there
3. Plant cells on the shaded side elongate more, so the plant bends towards the light source (positive phototropism

Question 3

Phototropism in roots

Answer 3

1. IAA inhibits cell elongation, IAA diffuses to the darker side of the root
2. So cells elongate more on the lighter side
3. therefore, the root bends away from light (negative phototropism)

Question 4

Gravitropism in shoots

Answer 4

1. IAA defuse to the lower side of the shoot
2. If the plant is on its side, it causes the shoot to bend upwards (negative gravitropism)
3. If the plant is vertical, plant cells elongate and plant grows up wards