responses in plants and animals

Question 1

why do plants grow towards light

Answer 1

to maximise light absorption for photosynthesis

Question 2

why do climbing plants have a sense of touch

Answer 2

so they can find things to climb up and reach the sunlight

Question 3

what a tropism

Answer 3

a plants response to directional stimulus

Question 4

what is a directional stimulus

Answer 4

a stimulus coming from a particular direction

Question 5

how do plants respond to a stimuli

Answer 5

by regulating their growth accordingly

Question 6

what is a positive tropism in terms of growth

Answer 6

growth towards a stimulus

Question 7

what is a negative tropism in terms of growth

Answer 7

growth away from a stimulus

Question 8

what is phototropism

Answer 8

plants response to light

Question 9

what is gravitropism

Answer 9

plants response to gravity

Question 10

what are growth factors

Answer 10

hormone like chemicals that speed up or slow down plant growth

Question 11

where are growth factors produced

Answer 11

in the growing regions of plants such as shoot tips or leaves and move to parts of the plant where they’re needed

Question 12

an example of a growth factor is auxins what do these do

Answer 12

stimulate the growth of shoots by cell elongation

Question 13

what is cell elongation

Answer 13

when the cell walls become loose and stretchy so the cells get longer

Question 14

what do high concentrations of auxins inhibit in roots

Answer 14

growth of roots

Question 15

where is indoleacetic acid produced

Answer 15

in the tips of shoots in flowering plants

Question 16

what does indoleacetic acid move by over short and long distances

Answer 16

1) short distances - diffusion and active transport

2) long distances - phloem

Question 17

what does the uneven distribution of indoleacetic acid in the plant mean

Answer 17

different parts of the plant have different concentrations of indoleacetic acid which means there’s uneven growth

Question 18

what is a tactic response (taxes)

Answer 18

when organisms move towards or away from a directional stimulus such as light

Question 19

what is a kinetic response (kineses)

Answer 19

when organisms movement is affected by a non directional stimulus such as humidity