Plant hormones - auxins

Question 1

How do plant respond to changes in their environment?

Answer 1

• Via hormones which act locally

Question 2

What is an auxin?

Answer 2

• Hormones in plants that are present in the tips of roots and shoots

Question 3

Explain phototropism

Answer 3

• In the shoots of plants
• Auxins accumulate on the shaded ide of the shoot and stimulate growth
• Shaded side grows faster than side in light
• Difference in rate of growth results in the shoot growing (bending) towards the light

Question 4

Explain gravitropism

Answer 4

• In the roots of plants
• Auxins accumulate on the lower side of the root and inhibit growth
• Upper side grows faster than the lower side
• Difference in rate of growth results in the root growing (bending) downwards (in the direction of gravity)