1- biology 🪩 > section 8 - > Flashcards

section 8 - Flashcards

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1
Q

cells need oxygen for

A

aerobic respiration which produces carbon dioxide as a waste product

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2
Q

surface area =

A

length x width

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3
Q

volume =

A

length x width x height

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4
Q

the alveoli are an ____ found in the _____

A

exchanged surface found in the lungs of mammals

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5
Q

alveoli are well adapted for

A

the efficient exchange of two important gases - oxygen and carbon dioxide

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6
Q

i’m single cell organisms, gasses and dissolved substances can diffuse…

A

directly into or out of the cell across the cell membrane - because they have a large surface area compared to the volume.

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7
Q

multicellular organisms (such as animals) have a smaller surface area compared to their volume this makes…

A

it difficult to exchange enough substances to supply their entire volume across their outside surface alone so they need some sort of exchange surface for diffusion and a mass transport system to move substances between the exchange surface and the rest of the body

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8
Q

the exchange surfaces have to allow enough of the necessary substances to pass through, so…

A

they are adapted to maximise effectiveness

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9
Q

gas exchange in mammals happen in

A

the alveoli

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10
Q

the job of lungs is to

A

transfer oxygen to the blood and to remove waste carbon dioxide from it

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11
Q

the lungs contain millions of little air sacs called _____ where _____

A

alveoli , where gas exchange takes place

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12
Q

blood arriving at the alveoli has just returned to the longs from the rest of the body, so it contains _______

A

lots of CO2 and not much O2 , this maximum es the concentration gradient for the diffusion of both gases

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13
Q

substances diffuse faster if…

A

theres a larger difference in concentration gradient

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14
Q

O2 diffuses ____

A

out of the air in the alveoli and into the blood

high concentration to low

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15
Q

CO2 diffuses in ….

A

the opposite direction of oxygen to be breathed out

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16
Q

how are alveoli adapted to maximise the diffusion of O2 and CO2 ?

A

moist lining for dissolving gases

good blood supply to maintain the concentration gradient of CO2 and O2

very thin walls to minimise the distance gasses have to travel

large surface area (75m^2 in humans)

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17
Q

red blood cells carry

A

oxygen

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18
Q

the job of red blood cells are

A

to carry oxygen from the lungs to all the cells in the body

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19
Q

red blood cells have a biconcave disc shape because….

A

to give a large surface area for absorbing oxygen

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20
Q

red blood cells don’t have a

A

nucleus - this allows more room to carry oxygen

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21
Q

red pigment in red blood cells are called

A

haemoglobin which contains iron

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22
Q

in the lungs, haemoglobin binds to …

A

oxygen to become oxyhaemoglobin

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23
Q

in body tissues, oxyhemoglobin …

A

splits up into haemoglobin and oxygen to release oxygen to the cells

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24
Q

what do white blood cells do

A

they defend against infection

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25
do white blood cells have a nucleus?
yes
26
what are phagocytes
white blood cells that can change shape to engulf unwelcome microorganisms- this is called phagocytosis
27
lymphocytes are …
white blood cells that produce antibodies against microorganisms , some also produce antitoxins to neutralise any toxins produced by the microorganisms
28
what happens to whit blood cells when you have an infection
they multiply to fight it off
29
what do platelets do?
help blood clot
30
what do platelets do?
help the blood to clot at a wound to stop all your blood pouring out and to stop microorganisms getting in
31
lack of platelets cause
excessive bleeding and bruising
32
what is plasma
liquid that carries everything in blood
33
what does plasma carry
red and white blood cells, platelets nutrients like glucose and amino acids carbon dioxide urea from the liver to the kidneys proteins hormones antibodies and antitoxins produced by wbc
34
three types of blood vessels
arteries - carry blood AWAY from the heart capillaries - these are involved in the exchange of materials at the tissues veins - these carry the blood TO the heart
35
the heart pumps the blood out at a high pressure so..
the artery walls are strong and elastic
36
the walls of the arteries are …
thick compared to the lumen (size of the hole down the middle)
37
arteries contains a thick layer of…
muscle to make them strong, and elastic fibres to allow them to stretch and spring back
38
capillaries are small, they contain…
thin walls, nucleus of cells, very small lumen
39
arteries branch into..
capillaries
40
capillaries have
permeable walls, so substances can diffuse in and out
41
how thick are capillaries
one cell thick, this increases the rate of diffusion by decreasing the distance over which it occurss
42
capillaries supply
food and oxygen and take away waste like CO2
43
capillaries join up to
form veins
44
blood is at a lower pressure in the veins so the walls don’t need..
to be as thick as artery walls also have a bigger lumen than arteries to help blood flow despite the lower pressure veins have valves to help keep the blood flowing in the right direction
45
what circulatory system to mammals have?
double circulatory system this means the heart pumps blood around the body in two circuits
46
double circulatory system
two circuits 1st circuit pumps deoxygenated blood to the lungs to take in oxygen , oxygenated blood returns to the heart 2nd circuit pumps oxygenated blood around all the other organs of the body to deliver oxygen to body cells , deoxygenated blood returns to the heart
47
fish have a …
single circulatory system - deoxygenated blood from the fished body travels to the heart which then pumps it right round the body again in a single circuit
48
heart pumps blood through the….
blood vessels
49
the mammalian heart has __ chambers and ________ major blood vessels
4 chambers four major blood vessels
50
the right atrium of the heart receives
deoxygenated blood from the body thru the vena cava
51
the deoxygenated blood moves through the…
right ventricle , which pumps it to the lungs via the pulmonary artery
52
the left atrium receives …
deoxygenated blood from the lungs thru the pulmonary vein
53
the oxygenated blood then moves to the …
left ventricle which pumps it out around the whole body via the aorta
54
the left ventricle has a much thicker wall then the right ventricle because…
it needs more muscle because it has to pump blood around the whole body at high pressure whereas the right ventricle only has to pump it to the lungs
55
what do valves do
prevent backflow of blood in the heart
56
cardiac output =
heart rate x stroke volume
57
respiration is the process of…
transferring energy from the breakdown of organic compounds
58
what type of reaction is respiration
exothermic reaction
59
aerobic respiration equation
glucose + oxygen ——> carbon dioxide + water
60
anaerobic respiration doesn’t
require oxygen
61
anaerobic respiration equation
glucose ——> lactic acid
62
anaerobic respiration in plants equation
glucose ——> ethanol + carbon dioxide
63
rate of respiration practical (live organism one)
- soda lime granules are added to two test tubes, soda lime absorbs the CO2 produced by the respiring woodlice - ball of cotton wool is placed above the soda lime in each tube . woodlouse placed ontop if wo glass beads w the same mass as the woodlice are used in control tube respirometer is then set up as shown in the diagram syringe is used to set the fluid in the manometer to a known level apparatus is then left for a set period of time in a water bathe set to 15c decrease in volume of air in test time reduced pressure causing coloured liquids in manometer to move towards the test tube w woodlice distance moved in a given time is measured
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