Brainscape's Knowledge GenomeTM

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


See full index

Biology > Section 6: Chapter 14: Response to stimuli > Flashcards

Section 6: Chapter 14: Response to stimuli Flashcards

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

What are the positive outcomes of responding to a stimulus?

A
  • Increases survival ( can get away from dangerous stimulus).
  • Selection pressure - favours organisms with good responses.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How does a taxes work? (form of response)

A
  • DIRECTION depends on stimulus direction.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is a positive taxes?

A

Moving towards a stimulus.

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

What is a negative taxes?

A

Moving away from a stimulus.

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

What are 2 examples of taxes?

A
  • Algae moving towards light.

- Bacteria moving towards glucose.

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

What are the 3 types of response?

A

Taxes.
Kineses.
Tropism.

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

What form of response is algae moving towards light?

A

Positive phototropism.

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

What is kineses? (form of response)

A
  • Changes SPEED depending on stimulus.

- Either quickly turns to leave bad environment, or speeds up to get through it.

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

What is an example of a kineses?

A

Woodlice changing direction quickly to leave a dry environment.

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

What is tropism? (type of response)

A

GROWTH in response to a stimulus.

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

What is an example of tropism?

A
  • Plant shoots show positive phototropism (towards light).

- Positive gravitropism in roots.

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

What do plants have instead of hormones?

A

Plant growth factors.

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

What are plant growth factors equivalent to in humans?

A

Hormones.

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

What is the type of plant growth factor involved in plant cell elongation?

A

Indoleacetic acid (IAA) in auxin group.

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

What does IAA stand for? (plant growth factor)

A

Indoleacetic acid.

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

What is IAA involved in?

A

Plant cell elongation.

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

Describe positive phototropism in flowering plants (4 points).

A

1) Tip of shoot produces IAA. IAA transported down plant evenly.
2) Light causes IAA to move to shaded side of root.
3) Greater conc. of IAA on shaded side, so cells elongate more.
4) plant bends towards light.

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

Describe gravitropism in flowering plant roots (5 points).

A

1) Tip of root produces IAA. Transported evenly around root.
2) Gravity pulls IAA from upper to lower side of root.
3) Greater conc of IAA on lower side.
4) IAA inhibits elongation of root cells - so so lower side elongates less.
5) Elongation of upper side causes root to bend downwards.

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

How is IAA suitable for it’s function of elongation?

A
  • Increases plasticity in cell walls.

- Acid growth hypothesis - IAA causes AT of hydrogen from cytoplasm to cell wall to make it more flexible.

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

What are the 2 main divisions of the nervous system?

A

Peripheral NS.

Central NS.

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

What are the 2 divisions of the central nervous system?

A

Brain and spinal cord.

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

What are the 2 divisions of the peripheral nervous system?

A

Sensory NS.

Motor NS.

23
Q

What are the 2 divisions of the motor NS?

A

Voluntary NS.

Autonomic NS.

24
Q

What is a reflex?

A

An involuntary, rapid response to a stimuli.

25
Q

What is a reflex arc?

A

The pathway of neurones involved in a reflex.

26
Q

What are the stages of a reflex? (stimulus → receptor etc.)

A

Stimulus → receptor → sensory neurone → intermediate neuron/coordinator → motor neurone → effector.

27
Q

Why are reflex arcs useful?

A
  • No decisions making needed - can spend more time on complex responses.
  • Protect body from harm.
  • Fast - only 3 neurones.
28
Q

What is true of all sensory receptors?

A
  • Respond to changes in mechanical pressure.
  • Specific to single type of stimulus.
  • Convert stimulus energy to nerve energy (generator potential).
29
Q

What does the Pacinian corpuscle respond to?

A

Mechanical stimulus eg/ pressure.

30
Q

Where is the Pacinian corpuscle?

A

Deep in the skin in layers of tissue eg/ fingers.

31
Q

What is the name of the sodium channel involved in the Pacinian corpuscle?

A

Stretch-mediated sodium channel.

32
Q

Describe how the Pacinian corpuscle works (4 steps).

A

1) Pressure applied. Pacinian corpuscle becomes deformed - membrane stretches.
2) Stretching → sensory-mediated sodium channels widen. Sodium diffuses into neurone.
3) Sodium changes membrane potential (becomes depolarised). Generator potential produced.
4) Generator potential creates action potential (nerve impulse). Passes along neurones to central NS.

33
Q

What are the 2 types of light receptor cells in the retina?

A

Rod and cone cells.

34
Q

What type of cells are both rod and cone cells?

A

Light receptor cells.

35
Q

Where are the light receptor cells rod and cone cells found?

A

Retina.

36
Q

What are 5 key facts about rod cells?

A
  • Black and white images.
  • Detects light at low intensity.
  • Contains the pigment rhodopsin.
  • Has low visual acuity - hard to distinguish between 2 light sources.
  • Multiple synapses connect to one bipolar cell (giving low visual acuity).
  • Rhodopsin is slow to regenerate.
37
Q

What are 7 key facts about cone cells?

A
  • 3 types - each respond to different wavelengths.
  • View images in colour.
  • High light intensity needed to create generator potential.
  • Contains the pigment iodopsin.
  • Can distinguish between separate light sources because one bipolar cell to one cone cell.
  • Found in fovea.
  • Iodopsin is fast to regenerate.
38
Q

Which type of light receptor cell contains rhodopsin?

A

Rod cells.

39
Q

Which type of light receptor cell contains iodopsin?

A

Cone cells.

40
Q

Which type of light receptor cell detects light at low light intensities?

A

Rod cells.

41
Q

Which type of light receptor cell detects light at high light intensities?

A

Cone cells.

42
Q

What are the 2 divisions of the autonomic nervous system?

A

Sympathetic and parasympathetic NS.

43
Q

What division of the autonomic NS stimulates effectors and speeds up activity?

A

Sympathetic NS.

44
Q

What division of the autonomic NS inhibits effectors and slows down activity?

A

Parasympathetic NS.

45
Q

Define the word myogenic.

A

Creates electrical impulses without any outside help. (eg/ the heart).

46
Q

Describe the stages of controlling the heart rate (4 points).

A

1) SAN spreads electrical impulses around both atria, causing them to contract downwards.
2) Layer of non-conductive tissue stops impulses reaching the ventricles.
3) SAN impulses stimulate the AVN, and after a delay, the AVN releases electrical impulses called the bundle of His, that travels along purkinjie fibres.
4) Bundle of His causes purkinjie fibres to allow ventricles to quickly contract from apex upwards.

47
Q

What does SAN stand for?

A

Sinoatrial node.

48
Q

What does AVN stand for?

A

Atrioventricular node.

49
Q

Describe the stages of decreasing the heart rate.

A

1) Stretch receptors in aortic arc and carotid arteries detect increased bolood pressure.
2) More electrical impulses travel along sensory neuron to medulla- decreasing heart rate.
3) Increased electrical impulses travel along parasympathetic NS to SAN.
4) SAN releases less electrical impulses - decreasing hear rate.

50
Q

Describe the stages of increasing heart rate.

A

1) Chemoreceptors in the aortic arc and carotid bodies respond to pH changes. eg/ more CO2 = more acidic.
2) sensory neurons send electrical impulses to the medulla, increasing heart rate.
3) Increased frequency of impulses from sympathetic NS to SAN.
4) Increased blood flow increases CO2 removal.
5) pH returns to normal. slower impulses allow heart to get back to resting rate.

51
Q

Describe the reflex arc needed to decrease heart rate.

A 
Stimulus - Increased pressure.
Receptor - stretch.
Sensory neuron.
Coordinator - medulla.
Motor neurons.
Effector - SAN.
Response - Decreased impulses.
52
Q

Describe the reflex arc needed to increase heart rate.

A 
Stimulus - pH change.
Receptor - chemo.
Sensory neuron.
Coordinator - medulla.
Motor neurons.
Effector - SAN.
Response - Increased impulses.
53
Q

Where are stretch and chemo receptors found in the heart?

A

Aortic arc and carotid arteries.

Biology (11 decks)

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