Plant responses and seed growth

Question 1

External factors that affect plant growth

Answer 1

length of day
type of light
temperature
force of gravity

Question 2

Tropism

Answer 2

growth response of a plant to a directional stimulus

Question 3

Phototropism

Answer 3

Growth response to unidirectional light

Question 4

Geotropism

Answer 4

Growth response to force of gravity

Question 5

Plant growth regulator

Answer 5

chemical that at very low concentration affects the development of plants

IAA

Question 6

Germination

Answer 6

Re-growth of an embryo after a period of dormancy, if the conditions are suitable

Question 7

Dispersal

Answer 7

scattering of seeds from the parent plant

Question 8

Dormancy

Answer 8

resting period when seeds undergo no growth and have reduced cell activity or metabolism

Question 9

Advantages of dormancy

Answer 9

Avoid harsh weather conditions
gives embryo time to develop
provides time for dispersal

Question 10

Auxins

Answer 10

produced in meristematic cells in root and shoot tips

cause cell elongation

Question 11

advantages of plant growth regulators

Answer 11

selective weed killer

ethene ripens fruit

Question 12

Action of auxin similar to hormone

Answer 12

both carried in vascular systems

made in one location and an effect elsewhere

Question 13

3 factors for suitable germination

Answer 13

Oxygen, water, suitable water

Question 14

2 roles of water in germination

Answer 14

Soften the testa

transport nutrients

Question 15

inhibitory function

Answer 15

Apical dominance