Survival and response

Question 1

response

Answer 1

1)stimulus-detectable changes in the internal/external enviroment of an organism that leads to a response
2)receptor- detects stimulus,specifc to one type of stimulus
3)coordinator-formates a suitable response to a stimulus
4)effector produces a response to a stimulus
5)response

Question 2

simple refelx

Answer 2

-refelx arc=stimulus-receptor-sensory nuerone-coordinator(cns and relay)-motor nuerone-effector-response
-rapid because only 3 nuerones and few synapses
-autonomic because doesnt involve passage top brain
-protect from harmfull stimuli

Question 3

taxis

Answer 3

directional response by a simple mobile organism who moves towards a favourable stimulus or away from a unfavourable one

Question 4

kinesis

Answer 4

non directional response by a simple mobile organims who changes the speed of moveemnt and rate of direction chnage in response to a non directional stimulus

Question 5

tropism

Answer 5

growth of a plant in response to a directional stimulus
-posotive tropism-growth towards stimulus
-negative tropism-growth away from stimulus
involves growth factors like hormones

Question 6

phototropism

Answer 6

cell in tip of shoot produces IAA which is transported down the shoot
IAA coinc increases on shaded side
promotes cell elongation
shoot bends towards light

Question 7

gravitropism in roots

Answer 7

cell in tip of shoots produces IAA which is transported down
IAA conc increasews on lower side of the root
inhibits cell elongation
root curves down towards gravity