Plant Responses

Question 1

Plant hormones

Answer 1

Growth regulators affection how plant grows by stimulating plant cells to divide, enlarge, elongate, stop growing

Question 2

Plant hormones names

Answer 2

Auxins
Gibberellins
Abscisic acid

Question 3

Tropism & types

Answer 3

Growth or turning movement of plant /part of it in response to external stimulus
Phototropism & geotropism

Question 4

Phototropism & types

Answer 4

Growth of plant in response to stimulus of light.
Negative phototropism & positive phototropism

Question 5

Geotropism & types

Answer 5

Growth of plant in response to gravity.
Negative geotropism & positive geotropism

Question 6

Herbicide

Answer 6

Substance that is toxic to plants & destroy unwanted vegetation

Question 7

Apical bud

Answer 7

Growing point of stem located at tip of stem

Question 8

Apical dominance

Answer 8

When auxins produced at tip of stem inhibit the growth of branches closer to tip of stem

Question 9

Auxins functions

Answer 9

Apical dominance
Growth regulation
Cell division
Development of flowers & fruits

Question 10

Result of apical dominance

Answer 10

Auxins produced in tip of stem move downwards & inhibit growth of Lateral branches (Lateral buds).
Results in tapered growth of stem and branches being wider at bottom than tip.

Question 11

Advantages of stems being positively phototropic

Answer 11

Favorable position for leaves to recieve sunlight for photosynthesis
Allows easy pollination of flowers
Allows easier seed dispersal

Question 12

Auxins effect on roots and stem geotropically.

Answer 12

High concentration of auxins in root inhibit cell elongation (positively geotropic)
High concentration of auxins in stem promote cell elongation. Shoots are therefore negatively geotropic.

Question 13

Advantages of positive geotropism of roots

Answer 13

Able to grow deep into soil where root hairs will absorb water & minerals

Question 14

Gibberellin function

Answer 14

initiate the:
germination of seeds
Development of flowers & sprouting of buds.

Question 15

Purpose of Abscisic acid6

Answer 15

Inhibit growth of apical buds
Promotes seed dormancy

Question 16

Weeds & treatment

Answer 16

Unwanted plants that grow in an area & compete with other plants for space, nutrients, water, light..

1) Herbicides can be sprayed over crops to kill weeds however these are toxic to humans, animals & some plants
2) selective plant hormones like auxins sprayed on roots of weeds

Question 17

Plant defences

Answer 17

Chemical compounds
Mechanical defences: thorns, prickles, spines

Question 18

Dangers of auxins Herbicides

Answer 18

Poisonous as can be harmful to other organisms
Could kill beans as well thus reducing yield of crop