2.80 - 2.82 2.86 2.90

Question 1

what are examples of physiological factors that are controlled by homeostasis (6)

Answer 1

1. body temp
2. metabloic waste
3. blood pH
4. concentration of glucose in blood
5. water potential in blood
6. concentration of respiratory gases (co2 and O2) in the blood

Question 2

what are the two systems in mammals that transfer information to be transfered (homeostasis mechanism)

Answer 2

• nervous system
• endocrine system

Question 3

what does homeostasis do

Answer 3

maintains optimal conditions for enzyme action and cell function

Question 4

what do control systems that carry out a coordinated response require (4)

Answer 4

1. a stimulus
2. a receptor
3. a coordination centre
4. an effector

Question 5

what are the directional growth responses made in plants called

Answer 5

tropisms

Question 6

what is positive tropism

Answer 6

when the growth is towards the stimulus

Question 7

what is negative tropism

Answer 7

when the growth is away from the stimulus

Question 8

what is a response to light called (P)

Answer 8

phototropism

Question 9

what is a response to gravity called (P)

Answer 9

geotropism

Question 10

what do plants produce to regulate growth

Answer 10

auxins

Question 11

where are auxins produced

Answer 11

in the tips of the shoots and the roots they diffuse to the cells below the tips

Question 12

what happens when the auxin diffuses in the shoots and in the roots

Answer 12

shoots: auxins promote cell elongation

roots: auxins inhibit cell elongation

Question 13

how is information sent through the nervous system

Answer 13

ellectric impulses

Question 14

how do the electrical impulses travel

Answer 14

along neurons at hi9gh speeds

Question 15

what is the nervous system used for

Answer 15

to control functions that need instant responses

Question 16

what is the central nervous system composed of

Answer 16

brain
spinal cord

Question 17

what is the peripheral nervous system composed of

Answer 17

nerves

Question 18

what is a nerve

Answer 18

a bundle of neurons

Question 19

how is information sent through the endocrine system

Answer 19

through hormones (chemical substances)

Question 20

what is the endocrine system used for

Answer 20

control functions which do not need instant response

Question 21

where are the hormones produced

Answer 21

the endocrine glands

Question 22

what are adaptations of neurons

Answer 22

• they have a cell body
• some axons are over 1 meter long
• the axon is insulated by a fatty myelin sheath with small uninsulated sections called nodes - this means the electrical impulses jump from node to node
• they have many extensions called dendrites which create a network for easy communication

Question 23

what are the three types of neurons

Answer 23

• sensory
• relay
• motor

Question 24

what do sensory neurons look like

Answer 24

long
cell body branching off middle of axon

Question 25

what do relay neurons look like

Answer 25

short
small cell body with many dendrites

Question 26

what do motor neurons look like

Answer 26

long
large cell body
dendrites

Question 27

summarise the pathway through the nervous system

Answer 27

stimulus - sensory neuron - relay neuron - motor neuron - effector - response

Question 28

where the dendrites meet what is it called

Answer 28

synapse

Question 29

what does the synapse convert the electrical signal to

Answer 29

briefly as a chemical signal

Question 30

what are the chemical signaling molecules called in a synapse

Answer 30

neurotransmitters

Question 31

what is a reflex arc

Answer 31

the pathway of a reflex response