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Biology - Y10 + Y11 > Homeostasis -Y10 > Flashcards

Homeostasis -Y10 Flashcards

1
Q

What is homeostasis?

A

Maintaining a stable internal environment despite changing conditions

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2
Q

Why does the body need to maintain optimal conditions?

A

For optimal enzyme action and cell function

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3
Q

What is the role of a receptor?

A

Detects changes in the internal or external environment

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4
Q

What is the role of a coordination centre?

A

Interprets changes and organises a response

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5
Q

Name the two types of effectors and state what they do.

A

Muscles contract, whilst glands release hormones.

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6
Q

Is the nervous system or the endocrine system faster acting?

A

Nervous

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7
Q

Which system acts more generally across the body, the nervous system or the endocrine system?

A

Endocrine

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8
Q

What is negative feedback?

A

When the levels of something get too high or too low, they’re brouht back down to normal

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9
Q

CNS

A

Central Nervous System - consists of spinal cord and brain, connected to the body by sensory and motor neurones

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10
Q

Sensory neurone

A

Carry electrical impulses to the CNS

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11
Q

Motor Neurones

A

Carry electrical impulses from CNS to effector

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12
Q

Effector

A

Muslces and glands repond to nervous impulses

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13
Q

Synapse

A

Connection between 2 neurones

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14
Q

Pathway of reflex arc

A

stimulus ➔ receptor ➔ sensory neurone ➔ relay neurone ➔ motor neurone ➔ effector ➔ response

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15
Q

What is the role of a relay neurone?

A

To transfer a signal from a sensory neurone to a motor neurone

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16
Q

Why are reflex important?

A

They protect us from harm and injury

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17
Q

How do neurones work?

A
  • Nerve signal is transferred by chemicals which diffuse across synapse.
  • Chemicals set off a new electrical signal to next neurone
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18
Q

What is a reflex action?

A

**Automatic and quick response **that doesn’t involve a conscious part in the brain

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19
Q

3 reasons why treating the brain is difficult

A
  • Complicated, so hard to target with medications
  • Encased in skull, hard to access- fragile
  • Huge range of consequences: mental illness, tumours, infections
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20
Q

Ways to study the brain

A
  • Electrical stimulation on diff parts to see how it affects persons behaviour
  • MRI Scans - to see which part is most active during diff activities
  • Studying patrients with brain damage and link that part of the brain to its function
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21
Q

Cerebral cortex + describe it

A
  • Consciousness
  • Intelligence
  • Memory
  • Language
  • Highly folded, takes up most of brain
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22
Q

Cerebellum and where is it

A

Muscle coordination and balance
under (small) cerebral cortex

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23
Q

Medulla + where

A

Unconscious activiies - breath and heart rate
small on brain stem top

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24
Q

Hypothalamus

A

Responsible for regulating body temp

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25
Q

What hemisphere controls what?

A

Left hem - right side of body
Right hem - left side of body

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26
Q

Sclera

A

Tough, white supporting wall of the eye, protects eye

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27
Q

Cornea

A
  • Light rays enter through transparent outer layer found at the front of the eye
  • Job: To start the focussing of the light rays
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28
Q

Iris

A

Contains muscles that allow it to control the size of pupil

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29
Q

Pupil

A

Hole in the middle of iris - allows light rays to pass into eye

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30
Q

Lens

A

Focuses light onto retina (back of the eye)
* Can change shape so we can focus on distance/near objects - accomodation

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31
Q

Retina

A

Contains receptor cells sensitive to light intensity and colour

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32
Q

What controls the shape of the lens?

A
  • Ciliary muscles
  • Suspensory ligaments
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33
Q

Optic nerve

A

Carries electrical impulse from receptors on the retina to the brain

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34
Q

What happens to the eye in bright light?

A

Reflex triggered makes pupil smaller. Circular muslces in iris contract and radial muscles relax - reduces amount of light, protects from damage

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35
Q

What happens to the eye in dark light?

A
  • Sensed by light receptors in retina and send electrical impulses to brain
  • Brain send EI to specific muscles in iris
  • Radial muscles contract and circular muscles relax, makes pupile wider and dilated

reflex action

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36
Q

Process when eye looks at near objects

A
  1. Ciliary muscles contract, slackens/loosen the suspensory ligaments
  2. Lens becomes fat (more curved)
  3. Increases amount by which it refracts light
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37
Q

What is accomodation?

A

When the eye focuses light on the retina by chaging the shape of the lens

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38
Q

2 types of receptor cells and what they do in the retina

A
  • Cone cells = sensitive to colour of light - doesn’t work well in low light
  • Rod cells = more sensitive to light, only lets us see in black and white
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39
Q

Fovea

A

Place in retina which is full of only cone cells

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40
Q

What 2 muscles are the iris made out of?

A
  • Circular muscles - inner
  • radial muscles - outer
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41
Q

What is long-sightedness?

A

Hyperopia - when you can’t focus on near objects

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42
Q

How is the eye in long-sighted people?

A
  • Lens are the wrong shape
  • Lens don’t refract enough light
  • Eyeball could be too short
  • Images of near objects are brought into focus behind the retina
  • elderly = lens becomes less elastic, cant become thick enough for near
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43
Q

How to treat hyperopia?

A

Glasses with a convex lens - lens refract light rays so they can focus on the retina

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44
Q

What is short-sightedness?

A

Myopia - when you can’t focus on distant things

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45
Q

How is the eye in short-sighted people?

A
  • Lens is wrong shape
  • Lens refract too much light
  • Eyeball is too long
  • Images of distant objects are brought into focus in front the retina
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46
Q

How to treat myopia?

A

Glasses with a concave lens - so light rays focus on the retina

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47
Q

3 Alternatives of glasses

A
  • Contact lenses
  • Replacement lens surgery
  • Laser eye surgery
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48
Q

What is the eye?

A

Sense organ containing receptors sensitive to light intensity and colour

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49
Q

Thermoregulation

A

Control of body temp (37’)

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50
Q

What is the thermoregulatory centre?

A

Located in the hypothalamus, contains receptors that are sensitive to temp, receives impulses from receptors in skin

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51
Q

Mechanism for when you are hot

A
  1. Sweat produced by sweat glands which evaporates - transfers energy to environment from body
  2. Blood vessels dilate - more blood flows close to surface of skin (vasodilation) - helps transfer energy from skin to environment because more blood flows through capillaries - heat transfers out of blood
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52
Q

Mechanism for when you are cold

A
  1. Hair stand up to trap an insulating layer of air
  2. No sweat produced
  3. Blood vessels constrict to close off skins blood supply - vasoconstriction
  4. Shivering - skeletal muscles contract, to generate energy to shiver, muscles cells increase rate of respir. = releases heat + warms body
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53
Q

What are hormones?

A
  • Chemical messengers/molecules
  • Released directly into blood
  • Only affect particular cells in particular organs (target organs)
  • Produced by glands
  • Long-lasting
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54
Q

Pituitary glands

A
  • Produces many hormones and regulate body conditions
  • ‘master gland’ - hormones act on other glands
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55
Q

Thyroid

A
  • Produces thyroxine - regulates/increases rate of metabolism, heart rate and temp
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56
Q

Adrenal gland and where is it

A
  • Produces adrenaline - fight or flight response
  • top of kidneys
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57
Q

Pancreas

A
  • Produces insulin - regulates blood sugar levels
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58
Q

Ovaries

A
  • Produces oestrogen - menstrual cycle
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59
Q

Testes

A
  • Produces testosterone - puberty and sperm production
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60
Q

Difference between nerves and hormones

A

Nerves:
* Fast
* Acts on precise area
* Short time
* Travels via blood
* Uses electrical impulses which travel down neurones
Hormones:
* Slower
* More general
* Lasts a long time
* Uses hormones which are chemicals carried in bloodsrteam

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61
Q

What happens when blood glucose levels are too low?

A
  1. Pacreas detects low blood glucose level
  2. Causes pancreas to release hormone glucagon into blood stream
  3. Glucagon travels around body, binds mainly to cells in liver
  4. stimulates those liver cells to break down their stored glycogen into glucose and release it into the blood.
  5. Extra glucose increases levels to normal
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62
Q

What are the two main organs that insulin stimulates to absorb glucose from the blood?

A

Muscles and liver

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63
Q

What increases and decreases BGL?

A

Glucagon increases
Insulin decreases

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64
Q

Organ that detects changes in BGC

A

Pacreas

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65
Q

What happens if blood glucose concentrations fall too low?

A

There won’t be enough glucose for tissue cells to respire

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66
Q

What happens to excess glucose?

A

Stored as glycogen (hormone) in liver and muscles

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67
Q

What happens when blood glucose levels are too high?

A
  1. Pancreas detects level is too high releases insulin in bloodstream
  2. Insulin bind to receptors on certain cells (mostly liver and muscle cells to form glycogen) that causes them to take some glucose thats in the blood
  3. Levels decrease to normal
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68
Q

Type 1 diabetes

A
  • Pacreas produces little/no insulin
  • Need injections of insulin
  • Limit intake of simple carbs
  • Regular excercise
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69
Q

Type 2 diabetes

A
  • Obesity - risk factor
  • Resistant to own insulin (body doesn’t respond properly)
  • Carb controlled diet and excercise
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70
Q

What do the kidneys do?

A
  • Remove waste products
  • Regulate the level of ions
  • Regulate the amount of water in the blood
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71
Q

Filteration (kidneys)

A

Substances filtered out of blood as it passes through the kidneys

72
Q

Selective reabsorption

A

Useful substances like glucose, someions and right amount of water are reabsorbed babck into blood

73
Q

What substances are removed from the body in urine?

A
  • Urea
  • Ions
  • Water
74
Q

How is water lost?

A
  • Lungs when we exhale
  • Sweat from skin (+ ions, urea)
  • Urine - kidneys
75
Q

What happens to excess amino acids?

A
  • Liver breaks down excess amino acids
  • Produces ammonia
  • This process is deamination
  • Ammonia is toxic so liver converts it into urea
  • Excreted by kidneys
76
Q

Waste product of deamination

77
Q

What happens to ammonia?

A

It’s toxic so it’s converted to urea in the liver. Urea is transported to kidneys where it’s filtered out of the blood and excreted by urine

78
Q

What happens if there is a wrong amount of water in the body?

A

Upsets the balance between ions and water. Means too much or too little water is drawn into cells by osmosis. Can damage cells/ don’t work normally

79
Q

Ways ions are lost

A
  • Sweat
  • Urine
80
Q

ADH

A
  • Anti-diuretic hormone
  • Released into bloodstream by pituitary gland
  • Controls the concentration of urine
81
Q

How does ADH work?

A
  1. Brain (Hypothalamus) monitors the water content of the blood
  2. Pituitary gland releases ADH according to how much is needed
  3. Controlled by negative feedback
82
Q

What does the tubule do?

A

Carries the filtered fluid that becomes urine

83
Q

Blood enters the kidneys via the ———– and leaves via the ————.

A
  1. renal arteries
  2. renal veins
84
Q

Which structure carries urine from the bladder out of the body?

85
Q

Consequences of kidney failure

A
  • Waste substances build up in blood stream
  • No regulation in water and ion levels
  • Can cause death
86
Q

Dialysis

A

Machine that filters blood.

87
Q

In a dialysis machine, why is it important that the membrane between the blood and dialysis fluid is partially permeable?

A

To only allow some substances to diffuse across

88
Q

In a dialysis machine, why is it important to continually pump fresh dialysis fluid through the machine?

A

To maintain a concentration gradient for diffusion across the membrane

89
Q

Will fresh dialysis fluid contain urea?

90
Q

Disadvantages of dialysis

A
  • Risk of infection/blood clots
  • Unpleasant experience
  • Time consuming - 3 times a week, 3-4 hours
  • Expensive to run in long term
  • controlled diet
91
Q

If a patient has a kidney transplant, what type of drugs are they required to take for the rest of their lives?

A

Immunosuppressants

92
Q

Rejection of a transplanted organ process

A
  1. Immune system treat’s transplant as foreign so it tries to destroy it
  2. Reduce risk by using meds
93
Q

What is puberty?

A

Reproductive hormones causes secondary s characteristics to develop

94
Q

What is stage 1 of the menstrual cycle?

A

The uterus lining breaks down for about 4 days

95
Q

What is stage 2 of the menstrual cycle?

A

The uterus lining builds up again from day 4 to 14, into a thick spongy layer full of blood bessels, ready to receive a fertilised egg

96
Q

What is stage 3 of the menstrual cycle?

A

An egg develops and is released (ovulation) at day 14

97
Q

What is stage 4 of the menstrual cycle?

A

The wall is then maintained for about 14 days until 28 days. If there is no fertislised egg, cycle repeats and lining breaks down

98
Q

FSH

3 p

A

Follicle- Stimulating hormone:
* Produced in pituitary gland
* Causes egg to mature in 1 one of the ovaries, in a follicle
* Stimulates ovaries to produce oestrogen

99
Q

Oestrogen

3 p

A
  • Produced in ovaries
  • Causes lining of uterus to grow
  • Stimulates release of LH and stops release of FSH
100
Q

LH

2 p

A

Luteinising Hormone:
* Produced by pituitary gland
* Stimulates release of egg

101
Q

Progesterone

4 p

A
  • Produced in ovaries by remains of the follicle after ovulation
  • When this level falls, lining breaks down
  • Inhibits release of LH and FSH
102
Q

How does oestrogen stop pregnancy?

A
  • It prevents the release of an egg
  • If its taken everyday to keep the level permanently high, it inhibits the production of FSH, & after a while egg development and production stop and stay stopped
103
Q

How does progesterone prevent?

A

It stimulates the production of thick mucus which prevents any sperm getting and reaching the egg

104
Q

What is the combined oral contraceptive pill?

A

Pill which has oestrogen and progesterone

105
Q

Cons of the combined oral contraceptive pill

A
  • Side effects e.g nausea
  • Doesn’t protect against STI
106
Q

Contraceptive patch

A
  • Oestrogen and progesterone
  • 5cm X 5cm patch stuck onto skin
  • Lasts 1 week
107
Q

Contraceptive implant

A
  • Inserted under skin of arm
  • Releases continuous amount of prog.
    (stops ovaries releasing eggs, makes it hard for sperm to swim)
  • Lasts 3 yrs
108
Q

Contraceptive injection

A
  • Prog
  • dose lasts 2 to 3 months
109
Q

IUD

A
  • Intrauterine device is a T-shaped device
  • Inserted in uterus to kill sperm and prevent implantation of a fertilised egg
    2 types:
    Plastic IUD release prog
    Copper IUD prevent sperm surviving in uterus
110
Q

Diaphragm

A

Shallow plastic cup fits over cervix to form barrier
Has to be used with spermicide (disables/kills sperm)

111
Q

Sterilisation

A
  • Cutting or typing fallopian tubes
  • Permanent procedure
  • Very small chance tubes can rejoin
112
Q

Natural methods

A
  • Cycle is most fertile - avoid si
  • Ineffective
113
Q

Abstinence

A

Not to have it

114
Q

What is the role of LH and FSH in IVF?

A

To stimulate serveral eggs to mature

115
Q

Cons of using LH and FSH for fertility

A
  • Doesn’t always work - sometimes you have to repeat it - expensive
  • Too many eggs could cause multiple births
116
Q

What is IVF?

A

In Vitro Fertilisaiton

117
Q

Process of IVF

A
  1. Mother trated with FSH and LH - causes eggs to mature
  2. eggs collected from mother
  3. sperm from father is collected
  4. Sperm is used to fertilise eggs in lab.
  5. embryos formed
  6. once its a tiny ball of cells, inserted into uterus
  7. embryos develop
118
Q

Cons of IVF

4 p

A
  • Multiple births
  • Success rate of IVF is low
  • Emotionall/Physically stressful
  • Strong reactions to hormones - vomiting, abdominal pain
  • Not all embryos created will be transferred into the mother, so some destroyed unethical
  • Expensive = could be used in cancer
119
Q

What does adrenaline do?

4 p

A
  • Increase heart rate
  • Increase blood pressure
  • Increase blood flow to muscles
  • Increase blood sugar levels by stimulating liver to break glycogen down to glucose
120
Q

TSH

A

Thyroid stimulating hormone
* Released from pituitary gland

121
Q

Does thyroxine stimulate or inhibit the pituitary gland from releasing TSH?

A

Inhibit (stop)

122
Q

What happens when thyroxine levels are too high?

A
  1. Thyroxine will inhibit pituitary gland to produce TSH
  2. TSH stimulates thyroid gland to produce thyroxine so less TSH would decrease thyoxine production
  3. Thyroxine levels fall back normal over time due to negative feedback
123
Q

What do auxins do?

A

Plant hormone that controls growth near the tips of shoots and roots

124
Q

What way does auxin move and how?

A
  1. auxin produced at tip of shoot
  2. in shoots, auxin triggers cell growth
  3. light causes auxin to concentrate on darker side of the shoot tip
  4. Auxin spreads down the shoot
  5. Cells on darker side grow faster than cells on light side
  6. causes shoot to grow towards the light
125
Q

Does auxin inhibit or stimulate growth in the shoots and roots?

A

Shoots = stimulate
Roots = inhibit

126
Q

Phototropism

A

response to light

127
Q

Geotropism/ gravitropism

A

response to gravity

128
Q

Where are auxins accumulated?

A

Lower, shaded side

129
Q

What does positively phototropic and negatively geotropic mean for shoots?

A

They grow towards the light and away from the gravity

130
Q

3 hormones in plants

A
  • Auxins
  • Ethene
  • Gibberellin
131
Q

Auxins stimulate cells to grow and divide, so how can they be used as weedkillers?

A

If large amount of auxins are added to plants, it can disrupt their growth process by overstimulating them. This can kill the plant.

132
Q

Dormancy

A

Seeds are inactive and do not grow/develop

133
Q

Germination

A

Seeds begin to develop/grow

134
Q

Which plant hormone can stimulate a plant to geminate?

A

Gibberellin

135
Q

Explain how ethene is used in the transport of food.

A
  • Ethene stimulates food to ripen
  • Fruit is picked unripe so its still hard
  • Means it isnt damaged during transport
  • Ethene is used to ripen these fruit so it’s soft for conusmers
136
Q

What if there is too little water for cells?

A

Lose water and shrink

137
Q

What detects the water conc in the blood stream?

A

Hypothalamus

138
Q

What happens when the water levels are too low?

A
  1. Hypothalamus detects the low conc of water in bloodstream
  2. Send signal to pituitary gland to release ADH
  3. ADH reaches kidneys and causes tubules to reabsorb more water into the blood
  4. Water in blood increases
  5. Causes less urine to be produced
139
Q

What happens when water conc gets too high?

A
  1. Detected by hypothalamus
  2. Causes pituitary gland to stop sending ADH
  3. Less ADH travels to kidneys so tubules reabsorb water into blood
  4. More water will stay in the tubules so kidneys will produce more urine to get rid of extra water
140
Q

Explain how the pituitary gland and kidney reduce water loss

A
  1. low water conc/ low water potential of blood causes ADH release
  2. ADH causes increased permeability of kidney tubules to water
  3. so increased water reabsorbtion (more water taken into blood)
141
Q

Advantages of kidney transplant

A
  • Flexible lifestyle
  • No risk of infection from frequent needles
  • No need to control diet
  • Cheaper long-term for NHS/hospital
142
Q

Cons of kidney transplant

A
  • Doesnt last forever
  • Risks from surgery
  • Recovery from surgery will take a long time
  • Have to keep taking immunosurpressents so its not rejected by body
143
Q

Biological reasons why kidney transplants are better than dialysis

A
  • Not repeatdely puncturing skin - less chance of infection
  • Changes in conc levels of substances/ urea minimised so less chance damage to body cells
144
Q

Is urea toxic?

145
Q

Stages of the reflex arc

A
  1. Stimulus detected by receptor
  2. Electrical impulses from receptor along a sensory neurone to the CNS
  3. At the end of sensory neuron, there is a synapse
  4. Chemical released at synapse
  5. Chemical diffuses across to relay neurone in CNS where it triggers an electrical impulse
  6. Electrical impulse passes across relay neurone and reaches another synapse
  7. Chemical released
  8. Trigger an electrical impulse in a motor neurone
  9. Electric impulse down the motor neurone to effector
  10. Muscle contracts = response
146
Q

Ciliary muscles and suspensory ligaments

A
  • Work with the lens
  • allow us to focus on near/far
147
Q

What happens to the eye when focussing on distant objects?

A
  • light from distant needs to be focused only a small amount
  • ciliary muscles relaxes and suspensory ligaments are pulled tight
  • lens = pulled thin, so light rays slighly refracted
148
Q

What does the thermoregulatory centre contain?

A

receptors which are sensitive to the temp of blood

149
Q

What do the receptors in the skin do?

A

send electrical impulses down sensory neurones to thermoreg. centre

150
Q

How do the kidneys remove urea and adjust levels of water and ions

A
  1. Blood enters kidney through an artery (blood has urea)
  2. Kidney removes this urea as well as excess ions and water
  3. These leave the kidney as urine stored in bladder
  4. Blood leaves kideny through vein (has no urea now)
  5. Blood passes through capillaries where small molecules are filtered out of blood (urea, ions, water, glucose)
  6. These pass into a tube, all glucose, some ions and water is reabsorped into blood (selective reabsorption)
  7. urea, excess ions and excess water = urine
151
Q

What happens when the blood becomes too concentrated/ level of water in blood falls?

A
  1. Pituitary gland releases ADH into bloodstream
  2. ADH travels to kidneys = causes kidney tubules to become mroe permeable to water
  3. Means more water is reabsorped from the tubules back into the blood
  4. This causes less urine to be produced and amount of water in blood returns to normal level
  5. As level returns to normal, pituitary gland stops releasing ADH

negative feedback cycle

152
Q

What happens if the blood becomes too dilute when smn drinks a lot of water

A
  1. Pituitary gland stops releasing ADH
  2. So kidneys absorb less water into blood
  3. More urine produced + conc of blood returns back to normal
153
Q

Advantages of dialysis

A

no shortage of dialysis machines

154
Q

Disadvantages of kidney transplants

A
  • shortage of kidney donors
  • Patients need to take anti-rejection drugs for rest of life
155
Q

Pros of kidney transplant

A
  • only expensive initially
  • allow patrient = normal life
156
Q

Ethene use

A

controls cell division and the ripening of fruits

157
Q

Giberellin use

A

important in starting germination of seeds

158
Q

2 ways to treat infertility?

A
  • FSH and LH given to woman “fertility drug” causes more ovulation, increases chances of becoming pregnant
  • IVF
159
Q

RP 8

Method of effect of light intenisty affecting height

A
  1. Place cotton wool in 3 petri dishes and soak them with equal volume of water
  2. volume of water = cotrol
  3. plce 10 same mustard seeds in each dish
  4. Leave dishes in warm place and allow them to germinate
  5. water seeds everday with same vol of water
  6. after a few days, make sure each petri dish has same no of seedlings (control v)
  7. Use ruler to measure height of each seedling - hold stem straight, dont damage
  8. place 3 dishes in diff conditions
  9. 1 dish = full sunlight, 1 dish = partial light, 3rd = darkness
  10. measure height of each seedlng for 5 days in table
  11. calc mean seedling height for each day
  12. draw diagrams to see effect of diff light intensity
160
Q

what is auxin involved in

A

phototropism and gravitropism

161
Q

horticulture

A

growing plants for gardens

162
Q

Uses of auxin

A
  • weedkillers
  • rooting powders
  • promoting growth in tissue culture
163
Q

RP 7

Reaction time method

A
  1. 2 people
  2. Person 1sits on a stool with good upright posture
  3. Person 1 places forearm of dom arm across table overhanging table
  4. person 2 hold ruler vertically
  5. 0cm must be between person 1s thumb and first finger
  6. person 2 tells person 1 to prepare to catch
  7. person 2 drops ruler at random time
  8. person 1 catches asap
  9. person 2 records measurement above thumb
  10. repeated and mean
  11. switch places
  12. iv = person dv = reaction time control = starting distance between first finger and thumb, top of thumb, lighting, background noise
163
Q

Uses of giberellin

A
  • used to end seed dormancy - force seed to germinate earlier
  • encourage plants to flower
  • fruit grow larger
164
Q

What does laser eye surgery do?

A

change shape of cornea so it refracts light to a greater or lesser extent

165
Q

What does it mean in terms of water if the blood is too concentrated?

A

level of water is low

166
Q

What does ADH do?

A

increases water in blood
less urine produced

167
Q

Role of thyroxine

A
  • important for growth and development
  • metabolic rate - chem reactions faster
168
Q

TSH role

A

increases thyroxine production in the thyroid gland

169
Q

What do unequal distributions of auxin cause?

A

unequal growth rates in plants shoots and roots

170
Q

What does the skin have? What does the part 2 do?

A

temp receptors which send nervous impulses to the thermoregulatory centre which has receptors sensitive to tem p of blood

171
Q

How is the structure of the nervous system adapted to its funciton?

A
  • Long axon insulated by a fatty myelin sheath = long to carry msgs up and down bodt
  • Dendrites = receive incoming impulses from other neurones
172
Q

Where is water cooled?

A

mouth/stomach then sent to the brain

173
Q

How does the brain receive info about light?

A
  • cells in retina sensitive to light
  • impulse passes along sensory neuron
  • along to the optic nerve –> brain
174
Q

What lens would fix hyperopia?

A

convex - image behind retina becomes focussed on the retina

175
Q

When we look at a near object, what does the ciliary muscles do to have?

A

contract = smaller diameter

176
Q

In an experiment for geotropism, why does the pot with seedlings rotating slowly act as the control?

A

gravity acts evenly on all sides

Biology - Y10 + Y11 (6 decks)

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