COORDINATION AND CONTROL IN PLANTS

Question 1

What are the types of environmental stimuli plants detect?

Answer 1

light intensity, light duration, light direction, wavelength.

Question 2

How do plants detect these stimuli?

Answer 2

photoreceptors.

Question 3

What are the benefits of phototropism?

Answer 3

Plants receive the maximum amount of light for photosynthesis and development eg flowering at the right time of year.

Question 4

Give an overview of plant growth?

Answer 4

Cell division takes place in apex (apical meristem), cells enlarge below the tip (zone of elongation), certain times internodal regions elongate.

Question 5

What is plant growth controlled by?

Answer 5

Hormone like substances.

Question 6

What are the three main plant growth substances?

Answer 6

Auxins, Cytokinins, gibberellins.

Question 7

Explain the growth effect of auxins and where they are produced?

Answer 7

elongation of cells in zone of elgonation, apical meristem.

Question 8

Explain the growth effect and where auxin is produced?

Answer 8

elongation of cells in zone of elongation, apical meristem.

Question 9

Explain the growth effect and where cytokinin’s are produced?

Answer 9

cell division., actively dividing tissues.

Question 10

Explain the growth effect and where gibberellins are produced?

Answer 10

Elongation of internodal regions, apical buds and leaves.