Brainscape's Knowledge GenomeTM

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


See full index

IGCSE Biology > Disease, gas exchange, respiration, excretion, co-ordination > Flashcards

Disease, gas exchange, respiration, excretion, co-ordination Flashcards

Disease & immunity Aerobic respiration Anaerobic respiration Gas exchange in humans Excretion in humans nervous system

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

Types of pathogen [4]

A

1) Bacteria
2) Viruses
3) Fungi
4) Protozoa

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

Bacteria

A

Single-cell organisms without a nucleus Example: Strep throat, food poisoning, pneumona

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

Viruses

A

Non living particle

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

Define transmissable diseases

A

Is a disease in which the pathogen can be passed from one host to another

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

Diseases can be transmitted through.. [2]

A

1) Direct contact- blood or other body fluids
2) Indirect contact- contaminated surfaces or food, from animals, or from airborne pathogens

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

types of body defense systems [3]

A

1) Mechanical barrier- Skin and hairs in the nose
2) Chemical barriers- Mucus and stomach acid, antibacterial tears
3) Cellular barrier- Phagocyotsis and antibody production by lymphocytes, Can be enhanced by vaccination

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

Lymphocytes

A

Cells that tag foregin material (Antigen) with antibodies, targeting the material for destruction

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

Phagocytes

A

Eat/engulf foreign material through phagocytosis

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

Antibodies bind to antigens on pathogens

A

1) The shape of the antigen is complimentary to the binding groove on the protein antibody
2) Once the antibody-antigen complex is formed it marks the foreign material for destruction by phagocytes
3) Our body needs to create an antibody specific for every pathogen for an adpative immune response to occur

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

Define antigen [2]

A

1) Antigens are any structures that can be identified by an immune system
2) each organism has its own antigen

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

How to control the spread of diseases [3]

A

1) Clean water supplies
2) Hyigenic food preparation
3) Good personal hygiene
4) Waste disposal
5) Sewage treatment
6) Quarantine

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

Process of vaccination [4]

A

1) A weakened pathogen or specific antigen is put into the body
2) The antigen stimulates lymphocytes to produce antibodies
3) Complimentary antibody bind to the antigen, tagging it for destruction by phagocytes
4) Memory cells are produced that allow for the antibody to be produced rapidly in future, therefore giving you immunity

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

Why do we always feel more sick from first infections [2]

A

1) It takes our body mnay days to create antibodies that will fit an antigen if we have never been exposed to it
2) The second time our body is exposed it recognises the antigen much faster and can start producing antibodies within hours

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

Active immunity [3]

A

1) Defense against a pathogen by producing the antibody within the body
2) Is gained after an infection by a pathogen, or by vaccination
3) Memory cells are produced

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

Passive immunity [3]

A

1) Short term defence against a pathogen by antibodies acquired from another individual, e.g mother to infant from milk, mother to foetus through blood
2) Important for new-borns get all antibodies from the mother
3) Does not produce memory cells

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

Ventilation

A

Requires pressure so air can be forced in and out of the alveoli

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

function of diaphragm

A

Sheet of muslce that separates the thorax from the abdomen

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

WHere is intercostal mucles

A

Between the ribs

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

Process of inhalation [5]

A

1) Internal intercostal muscles relax and external intercostal muscles contract, pulling ribs up and out
2) Diaphragm also contracts and flattens
3) Volume of thorax increases
4) Air pressure in thorax decreases, creating a negative pressure
5) Air enters the lungs to equilibriate pressures

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

What muslces are contracting/relaxing in inhalation

A

1) Internal intercostal muscles relax and external intercostal muscles contract, pulling ribs up and out
2) Diaphragm also contracts and flattens

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

How inhalation affects thorax

A

Volume of thorax increases

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

How does inhalation affect the air pressure

A

Air pressure in thorax decreases creating a negative pressure

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

Air move in or out during inhalation

A

Air enters the lungs to equilibriate pressures

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

What muslces are contracting/relaxing in exhalation

A

1) Internal intercostal muscles contract and external intercostal muscles relax, pulling ribs down and in
2) Diaphragm also relaxes and moves up

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

How inhalation affects thorax

A

Volume of thorax decreases

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

How does exhalation affect the air pressure

A

Air pressure in thorax increases creating a positive pressure

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

Air move in or out during exhalation

A

Air exists the lungs to equilibriate pressures

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

Process of exhalation [5]

A

1) Internal intercostal muscles contract and external intercostal muscles relax, pulling ribs down and in
2) Diaphragm also relaxes and moves up
3) Volume of thorax decreases
4) Air pressure in thorax increases, creating a positive pressure
5) Air exists the lungs to equilibriate pressures

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

Cartilage in trachea

A

Made up of rings of cartilage
Helps keep trachea from collapsing

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

Route of oxygen

A

1) Down trachea
2) Through left and right bronchus
3) Through bronchioles within each lung
4) Alveoli is the site of gas exchange with bloodstream

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

Alveolus adaptations [4]

A

1) Covered in capillaries reducing diffusion distance
2) Alvoli only 1 cell thick reducing diffusion distance
3) Large surface area
4) Blood is flowing through capillaries, maintaning concentration gradient

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

How can you be infected with chlorea

A

Ingested via infected water or food, if it enters the small intestine it can cause illness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Explain how cholera causes diarrhoea [7]

A

1) Bacteria attach to the wall of the small intestine
2) They produce a toxin
3) The toxin stimulates the cells lining the intestine to release chloride ions from inside the cells into the lumen of the intestine
4) The chloride ions accumulate in the lumen of the small intestine and lower the water potential there
5) Once the water potential is lower than that of the cells lining the intestine, water starts to move out of the cells into the intestine (by osmosis)
6) Large quantities of water are lost from the body in watery faeces
7)The blood contains too little chloride ions and water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

How can severe diarrhoea lead to death?

A

loss of significant amounts of water and ions from the body, causing the tissues and organs to stop working properly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

How can cholera infection be treated?

A

oral rehydration therapy drink a small amount of salt and sugar dissolved in it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Define pathogen

A

Disease causing organism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Explain the role of vaccination in controlling the spread of diseases

A

Give protection against specific diseases and boost the body’s defence against infection without being exposed to dangerous diseases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Examples of active immunity [2]

A

1) The body has become infected with a pathogen and so the lymphocytes go through the process of making antibodies specific to that pathogen

2) Vaccination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Define antigen

A

All cells have molecules, such as proteins, projecting from their cell membranes
These are known as antigens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Example of passive immunity [2]

A

1) Through the placenta
2) Breast milk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Function of a larynx

A

Lid to stop food going down ur trachea when swallowing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Inspired air composition [3]

A

1) 21% oxygen
2) 0.04% carbon dioxide
3) 78% nitrogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Expired air composition [3]

A

1) 16% oxygen
2) 4% carbon dioxide
3) 78% nitrogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What is water vapor concentration like in exhaled air compared to inhaled air?

A

Water vapor concentration is higher in exhaled air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Respiration word equation

A

Oxygen + glucose -> Carbon dioxide + water + energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Goblet cells functions and location

A

In the lung epithelium
Produce and secrete mucus
looks like cups

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

How does mucus help our body

A

Traps bacteria, viruses, and any other particles that enter our lungs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Cilia functions and location

A

Small hairs on the surface of epithelial cells, they push mucus and other small particles towards the nose and throat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Pulmonary is to do with..

A

lungs
ex: pulmonary cells
pulmonary veins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Explain what happens to heart and lung as we exercise [2]

A

1) Our rate of breathing increases and the tidal volume (Air in and out per breath) this is to maintain concentrations of oxygen and low concentrations of carbon dioxide in alveoli, therefore maintaining the steep concentration gradients between blood and alveoli
2) Our heart pumps faster. to transport oxygen and glucose to body cells faster and to transport carbon dioxide in to alveoli faster to maintain the high rates of respiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Breathing during exercise [5]

A

1) Muscle cell respiration increases
2) The brain detects increasing pH in blood - a signal is sent to the lungs to increase breathing
3) Breathing rate and volume of air in each breath increase, more gaseous exchange
4) The brain tells the heart to beat faster
5) More oxygenated blood gets to muscle, CO2 is removed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

The effect of the catalyst on rate of reaction

A

Reactants require less energy to successfully collide therefore the frequency of successful collisions increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Ways energy is used in organisms [7]

A

1) Cell division
2) Actve transport
3) Movement
4) Temperature maintenance
5) Protein synthesis
6) Muscle contractions
7) Sending nerve signals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Define Aerobic respiration

A

The breakdown of glucose to release energy using oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Aerobic respiration equation word and chemical

A

1) glucose + oxygen -> carbon dioxide + water
2) C6H12O6 + 6O2 -> 6CO2 + 6H2O

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Pros and cons of aerobic respiration

A

1) Releases more energy per glucose molecule
2) Requires oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Define anaerobic respiration

A

The breakdown of glucose to release energy without oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Anaerobic respiration for yeast and muscle cells [3]

A

1) Yeast: Glucose -> alcohol + carbon dioxide
2) C6H1206 -> 2C2H5OH + 2CO2
3) Muscle: Glucose -> Lactic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Pros and cons of anaerobic respiration [2]

A

1) Does not require oxygen
2) Produces much less energy per glucose (ATP per glucose) . Also produces latic acid creating an oxygen debt that must be paid back later

60
Q

What happens when we cant get enough oxygen for aerobic respiration [3]

A

1) vigorous exercise cause our bodies to aerobically respire at a high rate. During this period oxygen is used faster in body cells than it can be replaced by gas exchange
2) Body cells run out of oxygen but they can still produce more energy using anerobic respiration however it creates lactic acid and it is inefficient
3) Anaerobic respiration creates an oxygen debt as oxygen is required to convert lactic acid back to pyruvate in the liver

61
Q

How to recover from oxygen debt [3]

A

1) Continue fast heart rate to pump lactic acid to liver faster
2) Continue deep and fast breathing to supply oxygen for aerobic respiration of lactic acid back into pyruvate
3) Aerobic respiration of lactic acid in the liver

62
Q

Carbon dioxide test

A

Bubble gas though lime water turns cloudy positive turns clear negative

63
Q

Define respiration

A

Chemical reactions that break down nutrients to release energy inside cells

64
Q

define yeast

A

SIngle cell fungus

65
Q

Define excretion

A

The removal of toxic materials, the waste products of metabolism, and substances in excess of requirements

66
Q

Organs in excretion [4]

A

1) Skin
2) Lungs
3) Liver
4) Kidneys

67
Q

Skin in excretion

A

Water and mineral ions

68
Q

Lungs in excretion

A

Carbon dioxide and water

69
Q

Liver in excretion

A

Produces urea from amino acids

70
Q

Kidneys in excretion

A

Excrete water, mineral ions, and urea

71
Q

Deamination definition and usage

A

De-aminonising so breaking down protein to make ureaU

72
Q

Ureter functions

A

Transports urine from the kidneys to the bladder

73
Q

Bladder functions

A

Collects urine prior to urination

74
Q

Urethra functions

A

Faciliates the removal of urine from body

75
Q

What is the role of kidneys [3]

A

1( Removal of urea from blood
2) Adjustment of ions in the blood
3) adjustment of water in the blood

76
Q

Roles of the kidneys [3]

A

1) Maintaining water and ion balance in the body
2) Filter urea out of blood and exrete it
3) Waste products are transferred to the bladder

77
Q

Removal of urea [3]

A

1) Proteins cannot be stored by the body so excess amino acids are broken down by the liver - this is called deamination
2) The waste product is urea and filtred out by the kidneys
3) Urea is toxic waste product so must be excreted before it reaches high concentrations

78
Q

Adjustment of ion content [2]

A

1) Ions such as sodium are taken into the body in food
2) Excess ions are removed by the kidneys

79
Q

Adjustment of water content (Too little water)

A

1) Hypothalamus detects & Pituitary releases AFH
2) More ADH enters kidney- more water is reabsorbed
3) Less urine which is more concentrated is produced

80
Q

Adjustment of water content ) Too much water in blood)

A

1) Hypothalamus detects & Pituitary releases less adh
2) Less water is reabosrbed so more urine and less concentrated

81
Q

Kidney structure [4]

A

1) Renal vein
2) Renal artery
3) Cortex
4) Medulla

82
Q

`Renal vein

A

Transports filtered blood back to the heart

83
Q

Renal artery

A

Transports in unfiltered blood from the aortta into the kidney

84
Q

Cortex

A

Blood is filtered here by nephrons

85
Q

medulla

A

Reabsorption of water to maintain water balance occurs here

86
Q

Ultrafiltration [2]

A

1) The glomerulus is a knot of blood vessels surrounded by the renal capsule
2) High blood pressure in the glomerulus forces water, ions, urea and glucose out of the blood
3) Smaller molecules are forced out of the capillaries of the glomerulus into the Bowman’s capsule

87
Q

Selective reabsorption [2]

A

1) Renal Reflection can be shown by the waves hitting a plane (straight) surface, such as a wall or mirror: All glucose is reabsorbed
Sufficient ions/salt is reabsorbed
SufSuffcient water is also reabsorbed
2) rest is passed on to the bladder as urine

88
Q

why is the urea produced?

A

The liver cant store protein so it breaks it down into aminoacids which contains nitrogen, so it becomes a toxic material,

89
Q

Factors the affect volume and concentration of urine [3]

A

1) Water (intake)
2) Exercise / sweat produce
3) The temperature (of the body or environment)

90
Q

Explain the importance of excreting carbon dioxide [3]

A

1) It dissolves easily in water which can dissolve in our body (70% water)
2) Lowers the pH of our blood
3) Denatures our enzyme

91
Q

Why antibiotics aren’t successful in treating influenza? [2]

A

1) Influenza is a virus
2) Antibiotics don’t destroy viruses

92
Q

Explain why a viral infection is not treatable with antibiotics [3]

A

1) Antibiotics are not effective against viruses
2) Antibiotics inhibit bacterial processes
3) Viruses replicate inside host cells which antibiotics cannot reach

93
Q

The measles vaccine will not give a child immunity against the influenza virus explain why [2]

A

1) Each pathogen has its own antigen
2) Antibodies for 1 type of pathogen won’t work for another type of pathogen

94
Q

spaniards visitied a tribe, the tribe died out due to influenza, but the spaniards were fine. Explain why [3]

A

1) The spaniards were carriers of the influenza
2) The tribe did not have immunity against pathogen whereas the spaniards did
3) This is due to the tribe’s lack of exposure to this type of pathogen.

95
Q

How does The body prevents particles in inspired air from reaching the gas exchange surfaces [4]

A

1) Hairs inside the nose trap particles
2) Particles become trapped in mucus
3) Cilia move the mucus by wafting/beating motion
4) Mucus moves away from the gas exchange surfaces towards the throat

96
Q

What causes the ribs to move during inspiration

A

intercoastal muscles

97
Q

factors that influence gas exhcange surfaces [4]

A

1) Good Ventilation
2) Good Blood supply
3) Large Surface area
4) THin walls

98
Q

Which type of tissue is effected by tracheal collapse? [2]

A

1) Cartilage
2) Trachea is made of rings of cartilage, if they are weak then the rings will collpase under negative pressure

99
Q

Why is good blood supply needed in the lungs [3]

A

1) Constant movement of blood in and out of the capillaries
2) Maintains high concentration gradient
3) So blood can be oxygenated fully

100
Q

Why did the temperature inside a small jar with crickets increase? Its the same temperature outside [3]

A

1) Crickets release energy and carbon dioxide
2) Carbon dioxide in a small confined space leads to greenhouse effect as it traps heat
3) Heat is also released from the kinetic energy of crickets

101
Q

Excess amino acids are broken down by [2]

A

1) Deamination to form urea
2) Part of amino acids is turned into ammonia which is turned into urea

102
Q

The name of the process that assembles amino acids to form proteins

A

Protein synthesis

103
Q

How lactic acid is processed? [3]

A

1) The processing of lactic acid requires oxygen
2) It is used during respiration to produce carbon dioxide and water
3) Enzymes catalyse the reaction

104
Q

Define nerve

A

A bundle of neurons

105
Q

What are electrical impulses? [2]

A

1) They are sent through nerves to quickly send signals around our body
2) Used for rapidly coordinating or regulating the bodies functions such as pupils dilating, stomach digests, and heart rate increase

106
Q

Immediate short term changes our body uses..

A

Nerves

107
Q

Delayed long term changes our body uses..

A

Hormones

108
Q

Central nervous system consists of…

A

Brain and Spinal cord

109
Q

Peripheral nervous system consists of…

A

All other nerves in the body

110
Q

Dendrites functions [2]

A

1) Receive signals from surrounding neurons
2) Branched to allow connections with many neuronsA

111
Q

Axon functions [2]

A

1) Long structure off the cell body that electrical signals can be rapidly sent through
2) Its long length allows for signals to be sent rapidly

112
Q

Axon termial function

A

Signal is passed to the next neuron over the synapse (Transmitts signal)

113
Q

Nerve signals are sent in one way or both way

A

One way

114
Q

How are nerve signals sent- reflex responses [5]

A

1) A stimulus is received by a receptor
2) Sensory neurons pass these signals back into a relay neuron in the CNS (Central nervous system)
3) The relay neuron sends this signal on to the motor neuron
4) The motor neuron sends the signal to an effector organ (Usually a muscle or gland) Which is then stimulated to respond
5) Reflexes allow us to respond to stimuli extremely fast without conscious thought and minimise damage

115
Q

What happens if you dipped ur hand in a hot pot? [5]

A

1) Pain receptors in ur skin were activated due to stimulus of hot pot
2) Sensory neurons passes signal from receptors back to the relay neuron in the CNS
3) Relay neuron passes signal to motor neuron
4) Motor neuron sends electrical signals on to an effector organ, the tricep and bicep
5) Effector organ responds to stimulus, moving ur hand away from the hot pot

116
Q

Dendron

A

singular of dendrite

117
Q

Define hormones

A

A chemical substance produced by a gland and carried by the blood

118
Q

Define involuntary action [2]

A

1) Automatic
2) Stimulus always leads to the same response

119
Q

Types of neurones [3]

A

1) Sensory neurone
2) Relay neurone
3) Motor neurone

120
Q

Define voluntary response [2]

A

1) Conscious decision to carry out an action
2) Takes longer than voluntary response since you are consciously thinking about it

121
Q

Fovea function [2]

A

1) Highest concentration of come cells with no rods
2) A tiny pit located in the retina provides the clearest vision of all

122
Q

Optic nerve function

A

Sends nerve signals from the rod and cones cells in the retina to the brain

123
Q

iris function

A

Is the coloured part of the eye which affects the size of the pupils

124
Q

Lens function

A

Is able to change shape to focus light onto the retina

125
Q

Pupil function

A

Is the opening in the eye which allows light to enter

126
Q

Cornea function

A

Is curved part of the eye which refracts light as it enters

127
Q

Suspensory ligaments function

A

Attach the lens to cillary muscles

128
Q

Ciliary muscles function

A

They contract or relax to make the suspensory ligaments go slack or tight respectively therefore changing the shape of the lens

129
Q

What happens when our eyes are in low light condiitions [2]

A

1) Radial muscles contract in low light so pupil will dilate
2) To absorb more light

130
Q

What happens when our eyes are in high light coniditions [2]

A

1) Circular muscles contract in bright light, so the pupil will appear smaller

131
Q

Iris reflex

A

controlling light

132
Q

Rod cells function [3]

A

1) Detect differences in light intensity
2) Do not detect clour
3) Used in dim light extensively

133
Q

Cone cells functions [3]

A

1) Detect differences in colour
2) Different cones detect red/blue/green
3) Cone = Colour

134
Q

Occipital lobe functions

A

Information is carried by sensory neurones to the occipital lobe where it is processed

135
Q

Fovea function

A

In the eye, a tiny pit located in the retina that provides the clearest vision of all

136
Q

Retina function

A

Contains light receptors

137
Q

What is the skin sensitive to? and what does it sense

A

pressure heat cold and pain
sense touch and temperature

138
Q

What is the tongue sensitive to? and what does it sense

A

Sensitive to chemicals in food and drink
senses taste

139
Q

What is the nose sensitive to? and what does it sense

A

Sensitive to chemicals in air
senses smell

140
Q

What is the ear sensitive to? and what does it sense

A

Sensitive to sound and movement
senses Hearing and balance

141
Q

What is the eye sensitive to? and what does it sense

A

sensitive to light
senses sight

142
Q

Explain how light is processed by the brain [3]

A

1) The retina contaisn rods and cones cells that are receptors for light coming in the eye
2) The retina will process the light into signals/impulses so it can be passed on by the sensory neurone to the brian
3) Optic nerves is a bundle of sensory neurone to send information collected by the rods and cones cells to the brain

143
Q

Reflex arc [7]

A

1) Stimulus
2) Receptors
3) Sensory neurone
4) Relay neurone
5) Motor neurone
6) Effector
7) Response

144
Q

How does a synapse work? [4]

A

1) Vesicles containing neuro transmitters are stored in the pre-synaptic membrane
2) These are released into the synaptic cleft
3) These neurotransmitters diffuses into the synapse
Which binds to the neurotransmitter receptor molecules on the surface of post-ynaptic membrane
4) this riggers an impulse in the second neurone

145
Q

Describe the process of accommodation in the eye

A

1) When we view objects far away, the lens needs to be thin so light refracts properly
2) Our ciliary muscle will relax while our suspensory ligaments will tighten so the lens is thin and pulled
3) When we view objects close, the lens needs to be thick
4) Ciliary muscle will contract while suspensory ligaments relax so the lens is squashed and thickens

146
Q

What is the distribution of rod and cone cells in nocturnal mammals

A

1) More rods than cone
2) More rods at the fovea

147
Q

yeast anaerobic respiration chemical equation

A

C6H1206 -> 2C2H5OH + 2CO2

IGCSE Biology (13 decks)

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