Coordination And Response In Plants

Question 1

How do plants increase their chances of of survival

Answer 1

Responding to changes in their environment, responding to the presense of predators, responding to abiotic stress-anything harmful but non living

Question 2

What is an example to plants responding to changes in the environment

Answer 2

Growing towards light to maximise photosynthesis

Question 3

What is an example of plants responding to the presence of predators

Answer 3

A white clover produces a substance toxic to cattle to prevent them being eaten

Question 4

What is an example of plants responding to abiotic stress

Answer 4

Carrots producing antifreeze proteins at low temperatures

Question 5

What are auxins

Answer 5

Auxins are plant hormones which control growth at the tip of shoots and roots
-auxin is produced in the tips and diffuses backwards it stimulate the cell elongation process which occurs in the cells just behind the tips
-auxin promotes growth in the shoot but inhibits growth in the roots
-auxins are involves in the growth response of plants to light and gravity

Question 6

What happens when shoots are positively phototropic

Answer 6

-the shoots grow towards the light
-when a shoot tip is exposed to light, it accumulates more auxin on the side that’s in the shade than the side in the light
-this makes the cells grow faster on the shaded and slower on the light side makes the shoot bends towards the light

Question 7

What happens when shoots are negatively geotropic

Answer 7

-shoots grow away from gravity
-when a shoot is growing sideways, gravity produces unequal distribution of auxin in the tip with more auxin on the lower side
-this causes the lower side to grow aster bending the shoot upwards

Question 8

What happens when roots are positively geotropic

Answer 8

-root grows towards gravity
-a root growing sideways will have more auxins on the lower side
-in a root extra auxin inhibits growth meaning the cells on tops grow faster and the root grows downwards

Question 9

What happens when Roos are negatively phototropic

Answer 9

-the root grows away from the light
-if the root starts to be exposed to light more auxin accumulates on the shady side
-the auxin inhibits cell elongation on the shaded side so the light side grows faster making the root grow downwards into the ground

Question 10

Why are roots negatively phototropic

Answer 10

-to absorb nutrients eg nitrates/water from soil
-to anchor plant