14.1 - Survival and Response

Question 1

Simple nervous system sequence

Answer 1

stimulus
receptor
sensory neurone
relay neurone
motor neurone
effector
response

Question 2

What is a taxis?

Answer 2

A simple response whose direction is dependent on the direction of the stimulus. Organisms either move towards favourable stimulus (positive taxis) or away from unfavourable (negative taxis) as a result of environmental change

Question 3

What is kinesis?

Answer 3

Form of response in which organism does not move towards or away from stimulus, it changes speed and rate at which it changes direction

Question 4

Advantages of kinesis responses

Answer 4

As organisms speed up and change directions more quickly, its chances of a quick return to favourable environment

Question 5

Example of kinesis

Answer 5

Woodlice move into dry areas, move much more quickly and change direction more frequently to avoid body water loss and return back to damp conditions

Question 6

What is a tropism?

Answer 6

Growth of part of a plant in response to a directional stimulus.
Towards = positive tropism
Away = negative tropism