Plant Responses

Question 1

Phototropism

Answer 1

Response to light

Question 2

Geotropism

Answer 2

Response to gravity

Question 3

Hydrotropism

Answer 3

Response to water

Question 4

Thigmotropism

Answer 4

Response to touch

Question 5

Chemotropism

Answer 5

Response to chemicals

Question 6

Phototropism:shoots and roots

Answer 6

Shoots are positively phototrophic to achieve maximum light for photosynthesis
Roots are negatively phototrophic to cause the root to grow down into the soil

Question 7

Geotropism:shoot and root

Answer 7

Roots are positively geotrophic

Shoots are negatively geotrophic

Question 8

Production site of auxin

Answer 8

Meristematic tissue

Question 9

Functions of auxin

Answer 9

Stimulating stem elongation 
Stimulating root growth
Developing fruit 
Causes phototropism 
Causes geotropism

Question 10

Effects of auxin

Answer 10

Inhibits growth of lateral buds
Fruit formation
Causes roots to grow

Question 11

Roll of auxin in phototropism

Answer 11

IAA is produced in growth tips
If stem is exposed to light , IAA will diffuse down the shaded side
As a result the stem grows towards the light

Question 12

Role of Ethene

Answer 12

Ripening of fruits
Stimulating leaves to fall in Autumn
Ageing of plants

Question 13

Experiment

Answer 13

10cm3 of IAA to first bottle
9cm3 of distilled water to next 7 bottles
Removed 1cm3 from 1st bottle and added to second
Repeated for other bottles
Placed filter paper on radish seeds in Petri dish
Added mixture and stood on their edge in incubator
Measured length of roots and shoots

Question 14

Growth regulators and hormones

Answer 14

Made at one site and function at another
Chemical
Transport is slow