(7.2) Control and Coordination

Question 1

What are the two types of movement exhibited by plants and how are they different

Answer 1

Nastic (non-growth, temporary, non directional response, immediate)

Tropic (growth, permanent, directional response, slow)

Question 2

How do plants move without growth

Answer 2

They change the amount of water in them, making them shrink or swell, hence changing their shape

Question 3

Roots growing downwards and shoots growing upwards are examples of

Answer 3

Geotropism and phototropism

Question 4

What are the limitations of electrical impulses?

Answer 4

1. will reach only those cells that are connected by nervous tissue
2. cells cannot continually create and transmit electric impulses

Question 5

Why do plants use chemicals to transmit information

Answer 5

Unlike electrical impulses, chemical compounds can diffuse and reach all cells

Question 6

auxin

Answer 6

synthesised at shoot tip
helps with growth

Ex: auxin diffuses towards portion of plant that is in shade, accelerating its growth and making the plant bend towards light

Question 7

Gibberellins

Answer 7

Growth of the stem

Question 8

Cytokinins

Answer 8

cell division
concentrated in fruits and seeds

Question 9

name 3 hormones in plants associated with growth

Answer 9

auxin, cytokinins, gibberellins

Question 10

Abscisic acid

Answer 10

Inhibits growth
Wilting of leaves