Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biology > 2.2 gas exchange > Flashcards

2.2 gas exchange Flashcards

1
Q

features allowing rapid diffusion of gases

A

large SA
thin
moist
permeable
good blood supply (some)

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

how does a large SA allow a rapid diffusion of gases

A

relative to the volume of the organism so that diffusion is rapid enough to meet its needs

gases have more area to diffuse

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

thin
rapid diffusion of gases

A

so that diffusion paths for gases are short

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

moist
rapid diffusion of gases

A

so that gases can dissolve before diffusion

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

permeable-
rapid diffusion of gases

A

to allow gases to pass through

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

what does increasing the size of an organism result in

A

a decreasing surface area to volume ratio

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

why do gas exchange surfaces need to adapt

A

-to meet the metabolic demands of different organisms
-as the size of an organism size increases

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

adaptations of amoeba

A

small single-celled organisms that live in aquatic environments
large SA compared to its volume so diffusion across the cell surface membrane can meet the needs of the whole organism (not just one cell)
gas exchange surface is thin resulting in short diffusion paths to the centre of its ‘body’

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

adaptions of flatworms

A

aquatics animals that have evolved a flattened shape
increasing the SA to volume ratio of the body surface for gas exchange
it also means diffusion paths for respiratory gases are short (no part of the body is far from the surface)

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

4 things

adaptations of earthworms

A
  1. live in damp soil environments that have evolved an extended tubular shape
    this increases SA to volume ratio
  2. keeps its body surface moist by secreting mucus
  3. more active, higher metabolic rate,
  4. longer diffusion paths than flatworms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what does it mean that earthworms are more active than flatworms

A

they have a higher metabolic rate, their tubular shape gives them a lower surface area to volume ratio than the flatworm and could result in a larger diffusion paths

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

examples of larger multicellular organisms

A

fish, amphibians, reptiles, birds, mammals and insects

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

what do the larger multicellular organisms have that are different

A

high oxygen requirements
smaller surface area to volume ratio

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

why do the larger organisms have high oxygen requirements

A

increased metabolic rate, they’re warm blooded, more active

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

why do the larger organisms have smaller surface area to volume ratio

A

usually much lager organisms

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

what do these larger organisms have that make gas exchange more efficient

A

a specialised gas exchange surface (gills/alveoli)
ventilation system
circulatory system
respiratory pigment

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

why does having a ventilation system make gas exchange more efficient

A

to maintain diffusion gradients by moving air or water over the exchange surface

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

why does having a circulatory system make gas exchange more efficient

A

to maintain diffusion gradients by transporting gases between respiring cells and the exchange surface

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

why does having a respiratory pigment make gas exchange more efficient

A

(haemoglobin) in the blood to increase its oxygen-carrying capacity

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

what do insects have in terms of gas exchange

A

small surface area to volume ratio, cannot use their body surface to exchange gases by diffusion
covered in hard, impermeable exoskeleton made of chitin sometimes with an additional waxy layer to reduce water loss

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

where does exchange if gases occur in insects

A

through pores called spiracles, running along the side of the body. gases then travel through the tracheal system- a branching system of chitin-lines tubes called tracheae

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

name of the ends if the tracheae

A

tracheoles
site of gas exchange
every cell in the body will be close to the end of the tracheal

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

what gases go where

A

oxygen enters, carbon dioxide leaves via the trachioles

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

gas exchange in less active insects

A

gases move along the tubes of the tracheal system by diffusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
gas exchange in more active insets
so rhythmical movement of the abdomen help to pump the air in and out of the abdomen and ventilate the tracheal system. this is a natural consequence of high energy activity like flight.
26
site of gas exchange in reptiles
occurs in the lungs they're sac like and have more complex folding than amphibians ventilation is aided by the movement of the ribs by the intercostal muscles
27
site of gas exchange in birds
blood capillary network
28
site of gas exchange in amphibians (frogs) when inactive
moist skin and mouth lining are the main sites of gas exchange. (on land or in water) if its inactive the frogs oxygen demands are low and can easily be met by these regions frog stays in damps areas so their skin stays moist. skin is moist and permeable with an extensive capillary network below it
29
site of gas exchange when active (amphibians)
two internal sac-like lungs are the site of gas exchange. when its active these organs provide the extra surface area needed to obtain extra oxygen
30
how are amphibian lungs ventilated
by movements of the mouth and nostril. no ribcages
31
what do lungs in frogs have
all the features allowing a rapid diffusion of gases
32
site of gas exchange in tadpoles
starts with gills (external) become internal before the lose them and develop a pair of lungs
33
different types of fish example
cartilaginous (marine only, made of cartilage) e.g shark bony fish (made of bone, scales and have gills covered by operculum) e.g every other fish
34
structure of gills
4 rows of bony, gill arches on each side of the fishes head gill filaments, gill arch, gill-rakers
35
function of gill-rakers
used to filter food (plankton) out of the water passing over them and often help protect the delicate filaments from damage.
36
site of gas exchange in fish
thin gill filaments
37
what are the gill filaments covered by what does this do
covered by smaller gill lamellae, these increase the surface area of the exchange surface
38
blood flow in the gills
flows through the gill arches, out into the filaments and then out again into the gill lamellae before making the return journey to the gill arch
39
water flow in the gills
flows over the gill lamellae as it passes through the gills and this is where gas exchange takes place
40
adaptations of fish gills for gas exchange
large SA thin good blood supply permeable NOT MOIST
41
how does the fish gills have a large SA
theres a large number of gill filaments and gill lamellae
42
how are the gills adapted to be thin
gill lamellae are very thin, short diffusion paths for gases to reach the capillaries
43
how are the gills adapted to have a good blood supply
have an extensive capillary network, maintains a diffusion gradient (for respiratory gases) between the water and the blood
44
how are the gills adapted to be permeable
have haenoglobin in the blood for carriage of oxygen
45
why are the gills not adapted to be moist
they are naturally moist as they live in water
46
explain the ventilation mechanism in bony fish (including volume and presuure)
mouth opens, opperculum closes buccal cavity floor lowers (volume increases, low pressure) water flows in (from a region of high pressure (outside mouth) to low (mouth) pressure mouth closes floor of buccal cavity rises (v decreases, p increases) water (high pressure) is forced over gills, oppercullum opens, water leaves
47
2 directions of blood flow
parallel counter-current
48
explain parallel flow
blood flows in the same direction as the water passing over the gills
49
explain countercurrent flow
blood flows in the opposite direction to the water passing over the gills
50
which direction of flow is better for the fish
counter-current to maximise the amount of oxygen that can be extracted from water
51
role of the trachea
transpots air to the bronchi
52
role of the bronchi
transports air to the bronchioles
53
job of the bronchioles
transports air to the alveoli
54
what are the alveoli
respiratory surface and the site of gas exchange
55
what is the pleural cavity
filled with pleural fluid which is made by the membranes
56
job of the pleural fluid
acts as a lubricant so that the ribcage can move more easily past the lungs as we breathe
57
what are organisms that have gas exchange surfaces outside their body in danger of
dehydration and excessive water loss
58
benefit of having an internal gas exchange surface
reduces water loss
59
what is the wall of the alveoli made up of
squarmous epithelium
60
adaptations of alveoli for gas exchange
large SA thin moist permeable good blood supply
61
how are alveoli adapted to have a large SA
lots of small alveoli
62
how are alveoli adapted to be thin
alveolar walls/ capillary walls are thin, they're one cell thick. this provides a short diffusion pathway distance for oxygen to enter the blood and carbon dioxide to leave the blood
63
how are alveoli adapted to be moist
contain surfactant, allows gases to dissolve, more efficient diffusion of gases
64
how are alveoli adapted to be permeable
they have a shared cell surface membrane between the capillary and the alveoli, this allows for the diffusion of gases
65
how are alveoli adapted to have a good blood supply
they provide a good blood supply/ capillary network. this maintains a steep concentration gradient for oxygen and CO2.
66
what is lung surfactant
a mixture of proteins and phospholipids that line the moist alveolar membranes reduces pressure, to expand alveoli during inhalation reduces surface tension and prevents them sticking together and collapsing during exhalation
67
explain what happens during inhalation
intercostal muscles push ribs out by contracting. ribcage moves up and out. diaphragm contracts down and flattens volume of thoracic cavity increases pressure in thoracic cavity decreases below atmospheric pressure resulting the direction of air back into the lungs
68
explain what happens during expiration
intercostal muscles relax and push ribs back in, ribcage relaxes down and in. diaphragm relaxes moves up dome shape. volume of thoracic cavity decreases. pressure in thoratic cavity increases above atmospheric pressure resulting direction of air out of the lungs
69
how does negative pressure breathing work
for air to enter the lungs, the pressure inside the lungs must be below atmospheric pressure
70
job of cilia
moves/sweeps the mucus away from the lungs
71
job of mucus
traps dust particles, made in goblet cells
72
job of goblet cells
mucus is made
73
where is mucus made
goblet cells
74
why is the basement membrane important
it is the layer that the cells sit on
75
type of blood vessels in lung
capillaries
76
type of muscle in the trachea
smooth muscle it is involuntary
77
what adaptations do leaves have
large surface area thin lots of chlorophyll good transport
78
why is it important leaves have a large surface area
so they can absorb light for photosynthesis (make glucose)
79
why is it important that leaves are thin
short diffusion paths
80
why is it important leaves have lots of chlorophyll
to absorb light
81
site of gas exchange for a plant
leaf
82
structure of a stomata
lower epidermis cells 2 guard cells
83
role of the guard cells
open and close the stomata, when the stomata is open, guard cells are smaller
84
role of the stomata
allow the exchange of gases between the atmosphere and the internal tissue of the leaf they also control water loss by evaporation from the leaf (transpiration)
85
describe the process of stomata opening
1- potassium ions are actively transported from the epidermal cells into the guard cells. requires ATP 2- the extra potassium ions and makati create a lower water potential in the guard cells 3- water moves into the guard cells by osmosis 4- the guard cells expand (become turgid) 5- guard cells curve away from each other 6- stoma pores open
86
why do the guard cells turn away from each other
because the inner wall of each guard cell is thicker and inelastic
87
how do stomata cells close
1- potassium ions transported out of the guard cells 2- water potential of the cell rises and water leaves 3- guard cells become flaccid as they lose water 4- cells straighten up 5- stoma pores close
88
how would cyanide effect the opening/closing of the stomata
cyanide is a respiratory inhibitor, it inhibits production of ATP. potassium ions won't be able to actively transport into the cell
89
why do the stomata close
reduce water loss
90
role of the waxy cuticle
reduces water loss from upper epidermis
91
role of upper epidermis
transparent cells lacking chloroplasts to maximise photosynthesis
92
role of palisade mesophyll cells
engaged, densely arranged and contain many chloroplasts
93
role of air spaces in song mesophyll
allow efficient gas exchange
94
role of the stomata
allow gases in and out of the lead (allow loss of water vapour to ensure a continuous flow up the stem to the leaves)
95
role of the xylem vessels
provide water for photosynthesis
96
role of the phloem
transport sucrose made in photosynthesis away from the leaf
97
role of the guard cells
control gas exchange and water loss by opening/closing the stomata
98
adaptations of the leaf for gas exchange
-spongy mesophyll tissue allows for the circulation of gases -plant tissues are permeated by air spaces -stomatal pores allow gas to enter and leave the leaf -gases diffuse through the stomata down a concentration gradient. gases then diffuse through the intercellular spaces between mesophyll cells

Biology (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions