Activity 1

Questions
Complete the table:

Answers to activity 1
a) Plant hormone✔
b) Phototropism✔
c) Growth of a plant root in response to gravity✔
d) Growth movement of a part of a plant in response to an environmental stimulus✔ [4]

Activity 2

Questions
QUESTIONS 1 to 2 are based on Diagrams I and II which illustrate the response of the tip of a young shoot to a light stimulus.

1. The arrow X represents the unequal distribution of …
   1. abscisic acid.
   2. mineral salts.
   3. gibberellins.
   4. auxins.
2. The curving of the shoot in Diagram II is due to more rapid cell growth in region(s) …
   1. 1.
   2. 2.
   3. 1 and 4.
   4. 3 and 4.
3. The diagram above represents …
   1. geotropism.
   2. apical dominance.
   3. phototropism.
   4. gravity.  3 × 2  [6]

Answers to activity 2
1. D✔✔
2. B✔✔
3. C✔✔ 3 × 2  [6]

Activity 3

1. Describe TWO methods used by plants as defence mechanisms (4)

Answers to activity 3
1.

• Plants have thorns✔ on their stems and leaves. They are unable to escape from herbivores, and the thorns are used to protect themselves. ✔
• The chemical secretion of plants is poisinous to some organisms. ✔
• Sticky secretions given of by plants make it difficult for insects and animals to eat the plant ✔ [4]