Brainscape's Knowledge GenomeTM

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


See full index

Biology > Response to Stimuli > Flashcards

Response to Stimuli Flashcards

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

How do organisms increase their chance of survival?

A

By responding to changes in their environment

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

What is a tropism?

A
  • Plant growth in response to directional stimulus

- can be towards (+) or negative (-)

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

What are the tropisms of the plant shoot?

A
  • Positive phototropism

- Negative geotropism

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

What are the tropisms for a plant root?

A
  • Negative phototropism
  • Positive geotropism
  • Positive hydrotropism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the advantages of the plant root tropisms?

A

leaves in most favourable position to capture light

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

What are the advantages of the plant root tropisms?

A
  • increase probability of roots growing in soil

- increase H2O and nutrient absorption

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

What are plant growth factors?

A
  • Regulate growth in response to directional stimuli

- Stages: mitosis and cell elongation

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

What does IAA stand for and what is it?

A

Indoleacetic Acid

An auxin which can cause cell elongation

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

How does IAA move thru the plant?

A

By diffusion

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

For phototropism in shoot tip, where does IAA accumulate?

A

The shaded side

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

How does IAA cause cell elongation?

A
  1. attaches to receptors on cell membrane
  2. causes release of H+ ions
  3. pH decreases
  4. hydrogen bonds in cellulose microfibrils disrupted
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

True or false: in roots, IAA increases cell elongation

A

False: in roots IAA inhibits growth

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

For geotropism in roots, where does IAA accumulate and why?

A

On the lower region to inhibit cell elongation, so top side can grow faster

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

Name 2 reasons why it is important for organisms to respond to stimuli?

A
  1. increase chance of survival

2. increase reproductive success (increase chance of beneficial alleles passes on)

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

What is taxis?

A

directional response

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

What is positive and negative taxis?

A 
\+ = towards stimulus 
- = away from stimulus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the actual names of the taxis for: water, light and chemical?

A

hydrotaxis, phototaxis and chemotaxis

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

What is kinesis?

A

non-directional response

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

How can you tell if the organism doesn’t favour the environmental conditions?

A

more rapidly the organism moves and with fewer turns

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

Receptors respond to only…

A

1 type of stimulus`

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

How is an action potential formed?

A

The generator potential exceeds the threshold

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

Receptors are transducers. What does that mean?

A

change one form of energy into an electrochemical impulse

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

The greater the stimulus….

A

the greater the frequency of action potentials, and increase time that they go on for

24
Q

Describe briefly how the Pacinian Corpuscle works

A
  1. lamellae deforms
  2. stretch mediated Na+ ion channels open
  3. Na+ opens diffuse thru
  4. depolarises the membrane causing a generator potential
25
Q

Which eye receptor can sense colour and has high visual acuity?

A

Cone cell

26
Q

where are rod and cone cells located in the retina?

A

Cone: fovea
Rod: periphery

27
Q

Which eye receptor is stimulated in low light and which is stimulated in high light intensity?

A

Low: rod
high: cone

28
Q

What is the name of the pigment that rod cells have?

A

Rhodopsin

29
Q

What is the name of the pigment which cone cells have?

A

Iodopsin

30
Q

Why do cone cells have high visual acuity?

A

each cell has own bipolar neuron and so separate signals sent to the brain so can distinguish which was stimulated

31
Q

How can cone cells produce colour images?

A
  • 3 types responding to different wavelengths

- different type of iodopsin which breaks down in presence of specific wavelength

32
Q

Why are cone cells stimulated at high light intensities?

A
  • own separate bipolar neuron so multiple cells can’t be combined to exceed threshold
  • iodopsin need more energy to break down
33
Q

Why do rod cells have low visual acuity?

A
  • Many rod cells attached to a single bipolar neuron

- single impulse to brain so can’t distinguish

34
Q

How can rod cells respond to low light intensity?

A
  • many rod cells connected to 1 bipolar neuron = increase chance of threshold exceeded
  • rhodopsin doesn’t need lots of energy to break down
35
Q

Define sensory neuron

A

carry nerve impulses from receptor towards CNS

36
Q

Define motor neuron

A

Carry nerve impulses away from CNS to effectors

37
Q

Define CNS

A

Made up of brain and spinal cord

38
Q

Define the peripheral nervous system

A

made up of pairs of nerves that originate from either brain or spinal cord

39
Q

Define the voluntary nervous system

A
40
Q

What is the difference between the voluntary nervous system and the autonomic nervous system?

A

voluntary: conscious control
autonomic: not voluntary

41
Q

Name 3 reasons why the reflex arc is important

A
  1. very rapid
  2. reduce/avoid damage/injury
  3. helps to maintain balance/posture
42
Q

What is the autonomic nervous system?

A

Controls involuntary activities of internal muscles/glands (sympathetic and parasympathetic)

43
Q

What does antagonistic mean?

A

Sympathetic and Parasympathetic nervous systems oppose one another

44
Q

What is the parasympathetic nervous system?

A

Stimulates effectors = speeds up activity (in response to stressful stimuli)

45
Q

What is the parasympathetic nervous system?

A

Inhibits effectors = slows down activity (in response to stimuli)

46
Q

The importance of the parasympathetic nervous system (2)

A
  1. helps conserve energy

2. Replenishes body’s reserves

47
Q

What is the role of the Sinoatrial node?

A

Generates + sends out electrical waves across wall of atrium = atrium contracts

48
Q

What is the role of the atrioventricular septum?

A

Non-conductive tissue that prevents electrical wave crossing to ventricles

49
Q

What is the role of the atrioventricular node and why is there a short delay in sending an impulse?

A
  • detects impulses from atria

- allow atria to finish contracting

50
Q

Why is the electrical impulse sent from the apex up the ventricle walls?

A

Prevents blood pooling in the apex

51
Q

The medulla oblongata has 2 centres:

A
  • Acceleratory

- Inhibitory

52
Q

How does the medulla oblongata increase heart rate?

A

Impulse sent to SAN via sympathetic system

53
Q

How does the medulla oblongata decrease heart rate?

A

Impulse sent to SAN via parasympathetic system

54
Q

What are chemoreceptors and where are they located?

A
  • detect changes in the pH (due to CO2 conc.)

- located in the carotid arteries

55
Q

Where are pressure receptors located?

A

in the carotid arteries and aorta

56
Q

Pressure increases: ___________ system

Pressure decreases: ___________ system

A

increase: parasympathetic
decrease: sympathetic

Biology (25 decks)

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