2. responses in plants and animals

Question 1

tropism

Answer 1

response to directional stimulus

Question 2

positive

Answer 2

towards stimulus

Question 3

negative

Answer 3

away from stimulus

Question 4

Phototropism (light)

Answer 4

shoots positive - grow towards

roots negative - grow away

Question 5

gravitropism (gravity

Answer 5

shots negative - grow up

roots positive - grow down

Question 6

growth factors

Answer 6

hormone like 
speed up or slow down plant growth 
produced in growing regions of plant/ tip 
move to where needed AT/diffusion
e.g. auxins

Question 7

IAA

Answer 7

indoleacetic acid (auxin)

Question 8

phototropism shoots

Answer 8

IAA conc increase on shaded side
cells elongate
shoot bends towards light

Question 9

phototropism roots

Answer 9

IAA conc increase on shaded side
growth inhibited
bends away from light

Question 10

gravitropism shoots

Answer 10

IAA conc increase lower side
cells elongate
grow upwards

Question 11

gravitropism roots

Answer 11

IAA conc increase lower side
growth inhibited
grow downwards

Question 12

taxes

Answer 12

directional stimulus

e.g. woodlice negative photo taxis - damp conditions (reduce water loss) concealed under stones (from predators

Question 13

kinesis

Answer 13

non directional
e.g. favourable conditions - move slowly turn less often (stay in favourable)

unfavourable - move faster turn more often (more likely to move favourable.
unfavourable for long time - straight lines

Question 14

investigate animal response

Answer 14

use choice chambres