Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology A-Level > Topic 14 and Topic 15 > Flashcards

Topic 14 and Topic 15 Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

A stimulus is

A

A stimulus is a detectable change in the internal or external environment of an organism that leads to a response in the organism.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Stimuli are detected by

A

Receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

A coordinator

A

Formulates a suitable response to a stimulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

An effector

A

Produces a response which has been detected by the receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

A taxis is

A

A taxis is a simple response whose direction is determined by the direction of a stimulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is positive taxis

A

Movement towards a stimulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is negative taxis

A

Movement away from a stimulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Positive Phototaxis

A

Moving towards light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Negative phototaxis

A

Moving away from the light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

A kinesis is

A

A kinesis is a form of response where the organism changes speed at which it moves and the rate at which it changes direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

A tropism is

A

A tropism is the growth of part of a plant in response to a directional stimulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

The CNS is

A

Made up of the brain and the spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The peripheral nervous system is

A

Made up of pairs of nerves that are from either the brain or the spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Phototropism definition

A

The movements of plants in response to light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Gravitropism definition

A

Plants response to gravity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Hydrotropism definition

A

Plants response to water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

IAA is

A

An auxin which controls plant cell elongation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Sensory neurones…

A

Carry nerve impulses from receptors towards the central nervous system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Motor neurones…

A

Carry nerve impulses away from the central nervous system to effectors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

The voluntary nervous system…

A

Carries nerve impulses to body muscles and is under conscious control

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

The autonomic nervous system…

A

Carries nerve impulses to glands, smooth muscle and cardiac muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

An involuntary response to a stimulus is called?

A

A reflex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Reflex arc definition

A

The pathway of neurones involved in a reflex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

The Pacinian corpuscle

A

Is a receptor which responds to mechanical pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are two things receptors can be?

A

They can be cells (e.g photoreceptor cells) or proteins on cell surface membranes (e.g glucose receptors are proteins found in cell membranes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is a generator potential

A

Energy converted from the stimulus into a nervous impulse by a receptor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What channel is in the centre of a Pacinian corpuscle

A

Stretch mediated sodium channel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

At resting state the stretch mediated sodium channels in the Pacinian corpuscle are…

A

Too narrow to allow sodium ions to pass along them so has a resting potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

When pressure is applied to the Pacinian corpuscle…

A

It becomes deformed and the membrane around its neurone becomes stretched which widens the sodium channels so sodium ions diffuse into the neurone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How do the sodium ions change the potential of the membrane?

A

The influx of sodium ions depolarises the potential of the membrane producing a generator potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Where are light receptor cells found and what are they?

A

They are found in the retina and they are rod and cone cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Rod cells…

A

Can only see in black and white

33
Q

The different types of cone cells

A

There are three for different range of wavelengths of lights and they contain iodopsin pigment

34
Q

The autonomic nervous system…

A

Controls the subconscious activities of internal muscles and glands

35
Q

The sympathetic nervous system…

A

Is part of the autonomic nervous system and it stimulates effectors so speeds up activity

36
Q

The parasympathetic nervous system…

A

Is the other part of the autonomic nervous system which inhibits effectors and and slows down activity

37
Q

The heart is myogenic what does that mean?

A

The contraction of the muscle is initiated from within the muscle itself instead of by nervous impulses from outside

38
Q

Control of heart rate 1

A

A wave of electrical excitation spreads out from the sinoatrial node across both atria causing them to contract

39
Q

Control of heart rate 2

A

A layer of non-conductive tissue prevents the wave from crossing to the ventricles

40
Q

Control of heart rate 3

A

The wave of excitation enters a second group of cells called the atrioventricular node which is between the atria

41
Q

Control of heart rate 4

A

After a short delay, the atrioventricular node produces a wave of electrical excitation between the ventricles along muscle fibres which make up the bundle of His

42
Q

Control of heart rate 5

A

The bundle of His conducts the wage through the atrioventricular septum to the base of the ventricles

43
Q

Control of heart rate 6

A

The wave of excitation is released from the Purkyne tissue, causing the ventricles to contract quickly at the same time from the bottom of the heart upwards

44
Q

Changes to the heart rate are controlled by…

A

Changes to the heart rate are controlled by an area of the brain called the medulla oblongata

45
Q

Two centres in the medulla oblongata

A

One centre that increases heart rate, which is linked to the sinoatrial node by the sympathetic nervous system and one centre that decreases heart rate, which is linked to the sinoatrial node by the parasympathetic nervous system

46
Q

Chemoreceptors

A

Are found in the wall of the carotid arteries and are sensitive to changes in the pH of the blood that result from changes in CO2 concentration

47
Q

Pressure receptors

A

Found in the walls of the carotid arteries and the aorta

48
Q

when the blood pressure is higher than normal, pressure receptors…

A

when the blood pressure is higher than normal, pressure receptors transmit more nervous impulses to the centre of the medulla oblongata which decreases heart rate

49
Q

When blood pressure is lower than normal, pressure receptors…

A

when the blood pressure is lower than normal, pressure receptors transmit more nervous impulses to the centre of the medulla oblongata which increases heart rate

50
Q

The nervous system uses nerve cells to…

A

The nervous system uses nerve cells to pass electrical impulses and stimulate their target cells by secreting chemicals called neurotransmitters

51
Q

The hormonal system produces…

A

The hormonal system produces hormones that are transported in the blood plasma to their target cells

52
Q

Neurones definition

A

Specialised cells adapted to rapidly carrying electrochemical changes called nerve impulses from one part of the body to another

53
Q

A motor neurone is made up of…

A

A cell body, dendrons (which divide into dendrites which carry nerve impulses towards the cell body), an axon (a single long fibre that carries nerve impulses towards the cell body), Schwann cells (surround the axon protecting it), a myelin sheath, nodes of Ranvier

54
Q

Sensory neurones

A

Transmit nerve impulses from a receptor to an intermediate or motor neurone

55
Q

Motor neurones

A

Transmit nerve impulses from an intermediate or a relay neurone to an effector such as a gland or a muscle

56
Q

Relay neurones

A

Transmit impulses between neurones

57
Q

the phospholipid bilayer of the axon membrane prevents…

A

sodium and potassium ions diffusing across it

58
Q

channel proteins?

A

span through the phospholipid bilayer and sometimes allow sodium or potassium ions through them by facilitated diffusion

59
Q

carrier proteins?

A

actively transport potassium ions into the axon and sodium ions out of the axon, called the sodium-potassium pump

60
Q

what charge is on the axon

A

the inside of an axon is negatively charged to the outside which is called the resting potential

61
Q

action potential?

A

when the charges reverse so the inside of the axon is positively charged so it has been depolarised

62
Q

resting potential?

A

the inside of the axon is negatively charged to the outside

63
Q

why does depolarisation occur

A

depolarisation occurs because the channels in the axon membrane change shape and open or close depending on the voltage of the membrane

64
Q

where on the axon does the depolarisation occur?

A

at a particular point on the axon membrane instead of the full axon membrane

65
Q

at resting potential what happens to the channels?

A

some potassium voltage-gated channels are open but the sodium voltage-gated channels are closed

66
Q

action potential definition

A

means that the axon membrane is transmitting a nerve impulse

67
Q

resting potential definition

A

means that the axon membrane is not transmitting a nerve impulse

68
Q

as one region of the axon produces an action potential…

A

as one region of the axon produces an action potential and becomes depolarised it acts as a stimulus for the depolarisation of the next region of the axon

69
Q

the previous region of the axon membrane…

A

the previous region of the axon membrane returns to its resting potential so it undergoes repolarisation

70
Q

what do synapses do

A

they transmit information from one neurone to another by neurotransmitters

71
Q

what neurone releases the neurotransmitters

A

the presynaptic neurone

72
Q

what are neurones seperated by

A

a small gap called the synaptic cleft

73
Q

what is the rounded end part of the axon called?

A

the synaptic knob which has lots of mitochondria and endoplasmic reticulum

74
Q

where is the neurotransmitter stored

A

the synaptic vesicles

75
Q

2 features of synapses

A

they can only pass information in one direction, they can do summation which trigger a new action potential if the latest action potential was of a low-frequency

76
Q

2 functions of synapses

A

they allow a single impulse along one neurone to initiate new impulses in lots of different neurones at a synapse so a single stimulus can create lots of responses and they allow multiple impulses to be combined at a synapse.

77
Q

Function process of synapse

A

a neurotransmitter is made in the presynaptic neurone and is stored in the synaptic vesicles, when an action potential reaches the synaptic knob the vesicles fuse with the presynaptic neurone to release the neurotransmitter, it then diffuses across the synaptic cleft and binds with receptor proteins in the postsynaptic neurone

78
Q

synapses that produce new action potentials in the postsynaptic neurone are called

A

excitatory synapses

79
Q

what is a cholinergic synapse

A

a synapse which releases the neurotransmitter acetylcholine

Biology A-Level (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions