Edexcel IGCSE Biology > Coordination and Response > Flashcards

Coordination and Response Flashcards

(53 cards)

Study These Flashcards
1
Q

Define homeostasis

A

Maintaining a constant internal environment despite external change

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

State 3 conditions which need to be controlled by the body

A
  • Temperature
  • Water levels
  • Blood glucose concentration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the 3 main parts to a coordinated response?

A
  • A stimulus (e.g. temperature change)
  • A receptor (to detect change)
  • An effector (to carry out the response)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What does auxin trigger?

A

Auxin triggers growth of the main stem of the plant (and it inhibits the growth of side shoots)

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

What is phototropism and which part of a plant is positively phototropic?

A

Phototropism is the growth of a plant towards a light source. The shoots are positively phototropic (they grow towards the light source)

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

What is geo tropism and which part of the plant is positively geotropic?

A

Geotropism is the growth of a plant towards the pull of gravity. The roots are positively geotropic (they grow down in the same direction as the pull of gravity)

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

How does auxin cause shoots to grow towards the light source?

A
  • Auxin collects on the shaded side
  • Auxin promotes cell growth
  • The shoot curves towards the light
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Give 3 differences between nervous and hormonal communication

A
  • Nervous communication uses nerve cells and impulses whereas hormones are secreted by glands and travel in the blood
  • Nervous communication is generally much faster than hormonal communication
  • Hormonal communication usually brings about longer lasting responses than nervous communication
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the difference between the central nervous system and the peripheral nervous system?

A

The central nervous system is the brain and the spinal cord. The peripheral nervous system is every other part of the nervous system.

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

How is an impulse transmitted between two neurones?

A
  • The impulse reaches the end of one neurone
  • A neurotransmitter is released and it diffuses across the gap
  • A new impulse is triggered in the next neurone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is a stimulus?

A

A stimulus is a change in the environment

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

What type of neurone connects a receptor to the CNS?

A

A sensory neurone

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

What is an effector?

A

A part of the body that brings about the response to a stimulus like a muscle or a gland

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

What type of neurone connects the CNS to an effector?

A

A motor neurone

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

Describe the reflex arc

A
  • Stimulus detected by a receptor
  • Impulse passed along sensory neurone to CNS
  • Impulse passed along motor neurone to effector
  • Effector brings about the response
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe the sequence of events involved in removing a hand away form a hot flame

A
  • Thermoreceptors in the hand detect the heat of the flame
  • An impulse is sent along the sensory neurone
  • The impulse passes through relay neurones in the CNS
  • The impulse then passes along a motor neurone and triggers the muscles in the arm to move the hand away
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the cornea and what is its function?

A

The transparent layer in front of the eye that protects the eye from damage

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

What is the iris and what is its function?

A

The coloured ring around the pupil that controls its diameter

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

What is the pupil and what is its function?

A

The pupil is the hole in the middle of the iris that lets light into the eye

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

What is the optic nerve and what is its function?

A

The nerve coming out the back of the eye that sends signals to the brain

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

What is the function of the lens?

A

The lens focuses the light rays onto the retina

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

What is the retina and what is its function?

Study These Flashcards
A

The retina is the back part of the eye and it converts visual stimuli into electrical impulses

23
Q

What do the ciliary muscles and suspensory ligaments do?

Study These Flashcards
A

They control the shape of the lens (accommodation)

24
Q

How does the eye focus on near objects?

Study These Flashcards
A
  • Ciliary muscles contact and suspensory ligaments relax, causing the lens to thicken
  • Thicker lens causes the light to refract more
25
How does the eye focus on far away objects?
- Ciliary muscles relax and suspensory ligaments stretch, which makes the lens thinner - Thinner lens causes the light to refract less
26
How does the eye respond to bright light?
The iris contracts, making the pupil smaller and letting in less light
27
How does the eye respond to a lack of light?
The iris relaxes which makes the pupil larger and lets in more light
28
Why does the temperature need to be controlled?
To provide a suitable environment for enzymes so that they can work fastest at their optimum temperature
29
Give 2 processes involving the skin that cool the body down
Sweating - Cools the body by evaporation Vasodilation - Allows blood to flow closer to the surface of the skin where it can cool
30
Describe the process of vasodilation
- The body detects a rise in temperature - Blood vessels supplying the capillaries at the skin surface dilate (the muscles in the vessels relax) - More blood flows closer to the skin where it can cool
31
Give 3 processes that work to keep the body warm
- Vasoconstriction - Shivering - Erection of hairs on the skin
32
Describe the process of vasoconstriction
- The body detects a drop in temperature - Blood vessels supplying the capillaries at the skin surface constrict (the muscles in the vessels contract) - Less blood flows closer to the skin surface so less heat is lost to the surroundings
33
What are hormones?
Hormones are chemical messengers that are secreted by glands of the endocrine system in to the bloodstream
34
What does insulin do to the body?
Insulin decreases blood glucose concentration
35
Where is insulin secreted from?
The β cells of the pancreas
36
What does testosterone do?
- Main male sex hormone - Involved in growth of testes and penis - Triggers many changes in males during puberty (hair growth, deeper voice, increased muscle mass)
37
Where is testosterone secreted from?
The testes
38
When is adrenaline secreted?
During times of anxiety, fear or stress
39
Where is adrenaline released from?
The adrenal glands
40
Give 3 effects of adrenaline in the body
- Increased heart and breathing rate - Increases blood glucose concentration - Dilates the pupils
41
What does oestrogen do?
Oestrogen causes the uterus lining to thicken
42
Where is oestrogen secreted from?
The ovaries
43
What hormone does oestrogen inhibit?
Oestrogen inhibits follicle stimulating hormone (FSH)
44
What does progesterone do?
Progesterone maintains the uterus lining
45
Where is progesterone secreted from?
The ovaries
46
What hormones does progesterone inhibit?
Progesterone inhibits follicle stimulating hormone (FSH), and luteinising hormone (LH)
47
What does follicle stimulating hormone (FSH) do?
FSH stimulates the follicle to mature and release oestrogen
48
What does luteinising hormone (LH) do?
A surge in LH causes the release of an egg from a follicle (ovulation)
49
Where is FSH secreted from?
The anterior pituitary gland
50
Where is LH secreted from?
The anterior pituitary gland
51
Where is ADH secreted from?
The posterior pituitary gland
52
Name the Endocrine process if blood glucose is too high
- Blood glucose rises - Pancreas produces insulin - Insulin travels in blood to liver - Promote the uptake of glucose by liver cells - Liver converts glucose to glycogen for storage - Blood glucose levels decrease
53
Name the Endocrine process if blood glucose level is too low
- Blood glucose lowers - Glycogen released - Liver converts glycogen to glucose - Glucose released to blood stream - Blood glucose level increases
Edexcel IGCSE Biology
flashcards
Decks in class (31)
# Cards
Brainscape helps you reach your goals faster, through stronger study habits.
© 2026 Bold Learning Solutions. Terms and Conditions