Nervous System

Question 1

How do animals increase their chance of survival?

Answer 1

By responding to change in their external environement

Question 2

what is a stimulus?

Answer 2

A change in the internal or extertnal environment

Question 3

What are receptors?

Answer 3

Detect stimuli

Question 4

What are effectors?

Answer 4

bring about response to stimuli

Question 5

What are the 2 types of nervous system?

Answer 5

Central nervous system and peripheral nervous system

Question 6

What are the 2 types of peripheral nervous system?

Answer 6

1. Somatic nervous system - controls conscious decisions
2. Autonomic nervous system- controls unconscious activities

Question 7

What are the 2 types of autonomic nervous system

Answer 7

1. Sympathetic- gets the body ready for action, fight’ or flight ‘
2. Parasympathetic- calms the body down, it’s ‘rest and digest’

Question 8

What is a reflex?

Answer 8

A reflex is where a the body responds to a stimulus without making a conscious decision

Question 9

What is a reflex arc?

Answer 9

pathway of neurones linking receptors and effectors

Question 10

Give an example of a reflex arc for detection of heat?

Answer 10

1. thermoreceptors in the skin detect heat stimulus
2. sensory neurone carries impulse to relay neurone
3. relay neurone carries impulse of motor neurone
4. motor neurone sends impulses to the effector
5. muscle contracts to withdraw your hand and stop damage

Question 11

What are 3 key characteristics of nervous system communication?

Answer 11

1. when impulse reaches end of neurone, neurotransmitters are released to target cells so the response is localised
2. response is short lived as neurotransmitters are quickly removed
3. electrical impulses are really fast so the response is rapid

Question 12

What is tropism?

Answer 12

Tropism is the response of a plant to a directional stimulus

Question 13

positive tropism

Answer 13

growth towards the stimulus

Question 14

negative tropism

Answer 14

growth away from the stimulus

Question 15

phototropism

Answer 15

growth of a plant in response to light

Question 16

gravitropism

Answer 16

growth of a plant in response of gravity

Question 17

What are growth factors?

Answer 17

Plants respond to directional stimuli using growth factors- these are hormone like chemicals that speed up or slow down plant growth

Question 18

What are auxins?

Answer 18

Auxins are growth factors stimulate growth of shoots by cell elongation. High concentrations of auxins inhibit growth in roots.

Question 19

What is IAA?

Answer 19

Indoleacetic acid is an important auxin that’s produced in the tips of shoots in flowering plants.

Question 20

How is IAA moved around the plant?

Answer 20

By diffusion and active transport over short and via the phloem over long distances

Question 21

What is the phototropism of roots and shoots?

Answer 21

positive, growth towards light for shoots
negative, growth away from light in roots

Question 22

What is the gravitropism of roots and shoots?

Answer 22

Negative, growth up and away from gravity in shoots
Positive, growth downwards towards gravity in roots

Question 23

Describe what happens in phototropism of IAA in shoots and roots.

Answer 23

IAA increases in concertation along the shaded areas so there’s uneven growth

Question 24

Describe what happens in gravitropism of IAA in shoots and roots.

Answer 24

IAA moves to the underside of shoots and roots so there is uneven growth

Question 25

what’s a taxes response?

Answer 25

organisms move towards or away from a directional stimulus

Question 26

what’s a kinesis response?

Answer 26

organisms movement is affected by a non directional stimulus

Question 27

receptors are …

Answer 27

specific to one type of cell