module 3.1: exchange surfaces Flashcards
1
Q
name the two types of epithelial tissue found in the lungs and airways.
A
- squamous
- ciliated
2
Q
the epithelial cells in the lungs are arranged into structures called alveoli.
explain how the alveoli create a surface for efficient gaseous exchange.
A
- wall is one cell thick for short(er)
diffusion, distance / pathway ; - squamous, cells / epithelium , provide
short diffusion distance / pathway ; - elastic so, recoil / expel air / helps
ventilation ; - create / maintain, concentration
gradient / described ; - large number (of alveoli) provide large(r)
surface area ; - small size (of alveoli) provide large(r)
surface area to volume ratio ; - (cells secrete) surfactant to maintain
surface area ;
3
Q
to improve gaseous exchange, the air in the alveoli is refreshed by ventilation. the air movement created by ventilation can be recorded using suitable apparatus.
(i) name the apparatus used to record these air movements
A
spirometer
4
Q
when the rubber sheet is pulled down the balloons expand. explain why the balloons expand.
A
- volume, inside / of, jar increases
- pressure inside, jar / balloons, decreases
- to below pressure in atmosphere ;
- (therefore) air, moves / pushed / forced, into, balloons /glass tube
5
Q
explain the meaning of the term tidal volume.
A
- volume of air, inhaled / exhaled
- in, one / each, breath
- during, steady / regular, breathing
6
Q
suggest how the teacher may have used the model to demonstrate tidal volume.
A
- up / down, movements (of rubber sheet / band)
- idea of: small / steady / regular, movements (of rubber sheet)
7
Q
explain the meaning of the term vital capacity.
A
- the maximum volume of air
- inhaled / exhaled, in one breath
8
Q
suggest how the teacher may have used the model to demonstrate vital capacity
A
pulled down on rubber, sheet / band, as far as possible and pushed up as far as possible
9
Q
explain the significance of the relationship between rate of diffusion and the surface area to volume ratio for large plants
A
- (large plants) have a, small / low, SA : VOL ratio
- idea of diffusion too slow (to supply requirements)
- idea of need transport system (for water / minerals / assimilates) ;
- idea of need (special) surface area for, gaseous exchange/ uptake of minerals ;
10
Q
complete the table explaining how each adaptation improves efficiency of gaseous exchange
squamous epithelium
……………………………………….
large number of alveoli
……………………………………….
good blood supply
……………………………………….
good ventilation
……………………………………….
A
- squamous epithelium
short(er) diffusion, distance / path ; - large number of alveoli
large(r) surface area ; - good blood supply
high / large / steep, concentration gradient OR removes oxygen (from lung surface) / brings carbon
dioxide (to lung surface); - good ventilation
high / large / steep, concentration gradient OR supplies oxygen (to alveoli) / removes carbon dioxide (from alveoli) ;
11
Q
list three reasons why a large, multicellular animal, such as a mammal, needs a transport system
A
- low / small, surface area to volume ratio
- diffusion, too slow / distance too great
- to supply enough, oxygen / (named) nutrients
- to prevent, CO2 / (named) waste product, building up
- active
12
Q
explain what causes the change in the volume of air between points B and C on Fig. 5.1.
A
- (external) intercostal muscles / diaphragm, relax
- rib cage / ribs, move down OR diaphragm, moves / pushed, up
- volume of, thorax / chest cavity / lungs, drops / decreases ;
- pressure inside, thorax / chest cavity / lungs, increases ;
- above, external / atmospheric, pressure
- air leaves down pressure gradient
- (elastic) recoil of alveoli
13
Q
suggest why it is not possible to expel all the air from the lungs.
A
- thorax / rib cage / lungs, cannot be completely, compressed / flattened
- trachea / bronchi, held open by cartilage
- bronchioles / alveoli, held open by elastic fibres
14
Q
one of the symptoms of smoking is the development of a smoker’s cough.
explain how smoking causes a smoker’s cough and how the cough itself can lead to further problems in the lungs over a long period of time.
A
CAUSES
- tar
- (cigarette smoke) destroys / damages / paralyses, cilia / ciliated epithelium
- (cigarette smoke stimulates) goblet cells to release more mucus
- mucus ( in airways) , builds up / cannot be removed
- more, pathogens / bacteria / viruses / microbes, collect / trapped / accumulate (in mucus)
- idea that cough is an attempt to , increase air flow / remove microbes, by removing mucus
EFFECTS
- (frequent coughing) damages / inflames, - (named) airway / alveoli / elastic fibres
formation of scar tissue airway / bronchi / bronchiole, walls thicken
- lumen of, airway / bronchi / bronchiole , narrows
- flow of air restricted
- (damage to alveoli causes) reduced surface area for , gas exchange / oxygen diffusion
15
Q
chronic obstructive pulmonary disease (COPD) is a combination of diseases that can result in coughing, breathing difficulties and fatigue. name two specific diseases that contribute to COPD.
A
- emphysema
- chronic bronchitis
- asthma
16
Q
one form of COPD develops because enzymes are released by phagocytes entering the alveoli. this enzyme action can break down elastin in the lining of the bronchioles and alveoli.
use the example of elastin breakdown to explain the induced-fit hypothesis of enzyme action.
A
- elastin is substrate
- (elastin / substrate) binds to / fits into , active site
- active site / enzyme / elastase / substrate / elastin, shape changes
- idea of closer fit (between active site and substrate)
- more bonds form (between substrate and active site)
- forms enzyme-substrate-complex / ESC ;
- idea that (change in shape of active site) destabilises / weakens , bonds (in substrate) / substrate activation energy reduced
- idea of further shape change of, active site / enzyme, after products form
17
Q
name the air sacs and state why there are many air sacs in the lungs
A
- alveoli
- to provide large(r), surface area / SA
18
Q
Name the type of epithelium in the walls of the air sacs
A
squamous/ pavement
19
Q
explain the role of these elastic fibres during ventilation.
A
- to prevent bursting
- recoil
- to return air sac to original, size / shape
- to help expel air
20
Q
explain how refreshing the air in the air sacs helps to maintain a steep diffusion gradient
A
- increases, partial pressure / concentration, of oxygen (in the air sac)
- so concentration of oxygen (in the air sac) is higher than that in the blood
- decreases, partial pressure / concentration, of carbon dioxide (in air sac)
- so concentration of CO2 (in the air sac) is lower than that in the blood
21
Q
describe and explain one other way in which a steep diffusion gradient is maintained in the lungs.
A
- (continuous) blood flow (in the capillaries)
- to, bring in (more) carbon dioxide / take away (more) oxygen ;
OR - oxygen combines with haemoglobin ;
- to keep concentration in, blood / plasma, low ;
22
Q
using the mammalian gaseous exchange system as an example, explain how the different cells and tissues enable the effective exchange of gases
A
- thin endothelium (of capillary) ;
–> (provides) short diffusion distance / described ; - ref to surfactant (from epithelial cells) ,
–>reducing surface tension / preventing alveoli collapsing - blood / red blood cells / erythrocytes ;
–> transports (named) gas(es) , to / from ,
exchange surface / alveoli ; - diaphragm / intercostals , muscles ;
–> (maintains / creates) diffusion / concentration , gradient ; - ciliated epithelium / goblet cells / ciliated cells
–> idea of: protection from / removal of ,
dust / bacteria / pollen / spores - cartilage
–> hold airway open - smooth muscle
–> constrict / control diameter of , airway / blood vessel - elastic , fibres / tissue ;
–> for recoil / aiding ventilation - macrophage / neutrophil
–> engulf / destroy pathogens
or
protect from infection
23
Q
describe how the spirometer would be used to measure tidal volume
A
- idea of not breathing through nose
- subject breathes , evenly / normally / regularly
- idea of (measure) height / amplitude , of waves (from trace)
- measure at least three waves and calculate mean
- detail of how spirometer works (e.g. as breathe in lid goes down
e.g. movement of lid recorded , on trace
e.g. pen attached to lid moves up
24
Q
describe how you could use a spirometer trace to measure the rate of oxygen uptake.
A
- measure , volume of oxygen used /
decrease in volume in chamber - e.g. draw line along tips of , peaks / troughs and e.g. find difference in height from one ,
peak / trough , to another - measure time taken (to use this oxygen)
- divide (volume) by time taken
25
suggest two factors that should be considered when carrying out a risk assessment for an experiment using a spirometer
- check health of volunteer
- oxygen used
- new / sterilised / disinfected , mouthpiece (for each volunteer)
- idea of: soda lime working
- sufficient oxygen in chamber
- water level not too high / water must not enter tubes
- ensure valves working correctly
26
histamine is a cell signalling molecule that stimulates smooth muscle in the wall of structure A to contract. suggest how histamine stimulates smooth muscle contraction
- (histamine), binds / attaches, to, receptor / glycoprotein
- in / on, plasma / cell surface, membrane (of muscle cell)
- complementary (shape)
- triggers response / causes effect, inside
cells
27
another action of histamine is to make capillary walls more permeable.
suggest two effects this increased permeability may have on the surrounding tissues
- more tissue fluid formed / increase in volume of tissue fluid
- increase pressure in tissue
- swelling / inflammation / oedema
- (more) white blood cells pass into tissues
- larger molecules / (named) proteins ,
pass into tissue fluid
28
outline the mechanism of inspiration
- diaphragm / intercostal muscles, contract
- diaphragm moves down / ribs move upwards and outwards
- volume of thorax increased
- pressure inside thorax falls
- to below atmospheric pressure (so air enters lungs)
29
suggest a chemical that could be used in chamber T to absorb carbon dioxide
soda lime / sodium hydroxide / potassium hydroxide / calcium hydroxide
30
explain why a person using the spirometer to measure their vital capacity should wear a nose clip
- to prevent, escape of air / entry of air, through nose OR to ensure all air breathed comes from chamber
- make results invalid
31
state two other precautions that should be taken when using a spirometer to measure vital capacity
- use (medical grade) oxygen / fresh air
- disinfect mouthpiece
- e.g. maintain constant temperature (so that volume of gases is not
affected); ensure, valve / hinge, is working; level of water correct; no leaks / airtight / lips sealed around mouthpiece
32
name the two types of cell, A and B, shown lining the bronchus
- goblet / mucus (secreting) cell
- ciliated (epithelium)
33
describe how cell types A and B work together to keep the lung surface clear of dust and other particles
-(A / goblet cells) release mucus
--> (mucus) traps, dust / particles / named particle
- ciliated cell / B / cilia, wave / waft / move, mucus
- to, top of trachea / back of mouth
34
state the function of the smooth muscle fibres
- to constrict the bronchus
35
explain why blood capillaries and alveoli are very close together
- short, distance / path / AW
- (so that) diffusion / concentration, gradient is, high / steep
- high rate of, (gas) exchange / diffusion
36
state the function of these elastic fibres
- recoil / expel air / prevent bursting
37
explain, using the term surface area to volume ratio, why large, active organisms need a specialised surface for gaseous exchange
- large / active, organisms have high(er), demand for oxygen / need to remove CO2 ;
- small(er), surface area to volume ratio / SA:V / surface area : volume
- surface area too small / distance too large / diffusion takes too long
(to supply needs)
38
complete the table by explaining how each feature improves the efficiency of gaseous exchange. The first one has been completed for you.
- the epithelium of the alveoli
is very thin
- there are capillaries running
over the surface of the alveoli
- the lungs are surrounded by the diaphragm and intercostal muscles
- short (diffusion) distance
- delivers carbon dioxide (to be removed from blood) / carries oxygen away (from alveoli) OR short (diffusion) distance
- ventilation / supply of oxygen (to alveoli) / removal of carbon dioxide (from alveoli)
39
outline how the diaphragm and intercostal muscles cause inspiration
- diaphragm (contracts / flattens and) moves downwards
- intercostal muscles contract to move ribs, up / out
- increase volume of thorax
- reduce pressure inside thorax
- to below atmospheric pressure/creates pressure gradient
40
one research study has looked at the effectiveness of drugs used to treat asthma in children. asthma is a condition in which the bronchioles become reduced in diameter. this results in
the child finding it difficult to breathe.
(i) Using your knowledge of the structure of bronchioles, suggest how their diameter might become reduced
- contraction of smooth muscle
- circular (muscle)
- extra mucus production
- inflammation
41
explain why it is difficult to expel air from the lungs if the bronchioles become reduced in diameter
- (reduced diameter means) increased
- resistance to air flow / friction
- idea that exhalation is passive
42
Explain why a single-celled organism, such as Euglena, does not need a specialised area to carry out gaseous exchange.
- large surface area to volume ratio
- small so demand for, O2 / CO2, is low
- idea of: diffusion (alone) is adequate to meet needs
43
Complete Table 1.1, stating the function of each of the cells and tissues. The first row has been completed for you
elastic tissue
…………………………………
ciliated epithelium
…………………………………
goblet cells
…………………………………
smooth muscle
…………………………………
- to help expel air
- waft / wave / move / , mucus
- secrete mucus
- constrict the airway
44
suggest why the Titicaca water frog has evolved the unusually large folds of skin seen in Fig. 21.1
- large / increase the, surface area / SA:Vol ratio ✓
- idea of: increase (the rate of) oxygen absorption /described ✓
- oxygen levels in the lake are low ✓
45
when out of the water, the Titicaca water frog is able to use its lungs to absorb oxygen. lungs contain specialised gaseous exchange surfaces.
describe and explain how one feature of the lungs provides an efficient gas exchange surface
- large surface area ✓
--> for (maximum) diffusion ✓
- squamous, epithelium / cells OR
alveolar wall, only 1 cell thick / thin ✓
--> (providing) a short diffusion distance ✓
- good, blood supply / ventilation ✓
--> maintaining / creating a (steep) concentration gradient ✓
46
volume C can be measured using an instrument such as a spirometer.
what breathing instructions would be given to a person whose volume C was being measured
- breathe in as deeply as possible / AW ✔
- (and) then force as much air out as possible ✔
47
Describe how the structures of the insect tracheal system and fish gills provide a large surface area for gas exchange.
- insect tracheal system
..........................................
- fish gills
..........................................
- many / branched, tracheae / tracheoles / tubes ✓
- many / AW , filaments / lamellae / plates ✓
48
the lugworm, Arenicola marina, is a species of segmented worm that lives in burrows in damp sand. they have hair-like external gills that increase the surface area available for gas exchange. many other species of segmented worm do not have external gills.
suggest why lugworms have evolved external gills
- oxygen is in short supply (in lugworm habitat) ✓
- rate of diffusion is, insufficient / too slow (to meet
needs) ✓
- lugworms have a smaller surface area to volume
- ratio (than some worms) ✓
- lugworms have a high(er) metabolic rate ✓
49
complete the table by putting a tick (✓) in each box if the feature is present and a cross ( x ) if the feature is absent in each structure.
the first row has been completed for you
- trachea: has cartilage, elastic fibres and goblet cells
- bronchi
- bronchioles
- alveoli
- bronchi: has cartilage, elastic fibres and goblet cells
- bronchioles: may or may not have cartilage, elastic fibres and goblet cells
- alveoli: doesn't have cartilage or goblet cells. does have elastic fibres
50
* compare and contrast the mechanism of expiration during the first 60 seconds of the trace with the mechanism of expiration when the subject was told to breathe out fully
NORMAL EXPIRATION
* passive
* diaphragm muscles relax
* diaphragm moves up / becomes
dome shaped
* external intercostal muscles relax
* ribs move down and in
* elastic fibres recoil
* volume of thorax reduced
* pressure in thorax increased
* pressure in thorax greater than
atmospheric pressure so air
moves out of lungs
FORCED EXPIRATION
* active
* requires energy
* internal intercostal muscles
contract
* ribs pulled down hard
* abdominal muscles contract
forcing diaphragm up
51
explain how Fig. 6.1 demonstrates the need for larger multicellular animals to have specialised exchange surfaces.
- surface area to volume ratio = 3 : 1 (small) and 1.5 : 1 (large) OR large, cube / animal, has smaller SA:vol OR small, cube / animal, has larger SA:vol ✓
- diffusion, distance / pathway, long / deep, in large, cube / animal or diffusion time long in large, cube / animal ✓
- relatively / proportionally, small(er) surface cannot supply large(r) volume of cells ✓
- specialised exchange surfaces needed for, oxygen / carbon dioxide / gases / nutrients / waste products
52
Fig. 6.2 and Fig. 6.3, on the insert, show images of exchange surfaces in a bony fish and an insect. with reference to both Fig. 6.2 and Fig. 6.3 and your own knowledge, outline how the respiratory
systems in a bony fish and in an insect are adapted to maximise ventilation and gaseous exchange.
BONY FISH VENTILATION
- water enters mouth
- ref. volume / pressure, change in buccal
cavity
- water, flows / pushed, over gills
- water leaves via operculum
- throughflow system / one direction of flow
BONY FISH GAS EXCHANGE
- gill, filaments / lamellae (shown on Fig. 6.2)
- large surface area
- thin
- short diffusion distance
- good blood supply / blood vessels (shown on Fig. 6.2)
- steep concentration gradient
- counter current system (water and blood move in opposite directions)
INSECT VENTILATION
- muscular movement
- abdominal, dorso-ventral flattening /
telescoping / pumping
- ref. volume / pressure, change in abdomen
- thorax, movement / shape change, in flight
- air drawn in or forced out
- size of spiracle, changes / controlled
- external gills in aquatic insects
- small size / large SA:vol of insects, means diffusion may be sufficient
INSECT GAS EXCHANGE
- gas / oxygen / CO2, diffuses along
tracheae (shown on Fig. 6.3)
- oxygen dissolves in water at tracheoles
diffuses into surrounding cells
- many tracheoles so large surface area
- spirals of chitin (shown on Fig. 6.3) hold
tracheae open
53
suggest why maggots do not need such well-developed exchange surfaces and transport systems
- maggots are smaller so have greater surface area to volume ratio (than adult flies) ✓
shorter diffusion distance ✓
idea that maggots less active so lower metabolic demand for O2 ✓
- no (hard) exoskeleton so can absorb oxygen by diffusion through, skin / cuticle ✓
54
describe how the trachea of a mammal is different from the trachea shown in Fig. 3
- mammals have just one trachea
and insects have multiple tracheae ✓
- mammals (much) larger diameter /
insects (much) smaller diameter ✓
- in mammals trachea has, cartilage / no chitin (support) and in insects tracheae have, no cartilage / chitin ✓
- mammals have, C-shaped ‘rings’ / incomplete circle, and insects have spiral (support) ✓
- mammal trachea is longer /
(individual) insect tracheae shorter ✓
- mammal trachea branch into bronchi
and insect tracheae branch into tracheoles ✓
- mammal trachea has, smooth muscle / goblet cells / ciliated epithelium and (individual) insect tracheae do not ✓
55
sjogren’s syndrome is a rare condition that can reduce the production of mucus.
suggest how the upper respiratory tract of a person with Sjogren’s syndrome might be affected
(more) infections / irritation / coughing ✓
56
suggest why goblet cells have large numbers of the cellular component labelled A - mitochondria
to provide, lots of / much, energy / ATP ✓
57
Suggest how the role of the cellular component labelled B - golgi apparatus - is relevant to the function of the goblet cell
- Golgi apparatus ✓
- to, modify / process / package, protein ✓
- ref. vesicles / secretion (of mucus) / exocytosis ✓
58
state the roles of these two components in mammalian gas exchange.
- cartilage
................................................
- elastic fibres
................................................
- stops, trachea / bronchus, from collapsing ✓
- recoil of, alveoli / air sacs ✓
59
when air enters the trachea, mucus secreted by ............................. cells traps dust and microorganisms. air diffuses through the bronchi and the bronchioles. smooth muscle in the bronchioles relaxes during the ‘fight or flight’ response. this response is produced by the sympathetic nervous system, which contains neurones that secrete the neurotransmitter ............................. .
during inspiration, both the ............................. and external intercostal muscles contract. the internal intercostal muscles only contract when expiration is .......................... .
- goblet ✓
- noradrenaline ✓
- diaphragm ✓
- forced / conscious / active / voluntary ✓
60
*outline the structures involved in the mammalian gaseous exchange system.
for each structure, explain how it increases the efficiency of gaseous exchange
NASAL CAVITY
* large surface area and good blood
supply, warms air
* mucus secreting cells, trap dust
and microbes
* moist surfaces, increase humidity
and reduce evaporation from
surfaces in lung
TRACHEA
* cartilage rings, stop it from
collapsing
* ciliated epithelium and goblet cells
secrete mucus, trap dust and
microbes and move them towards
stomach
BRONCHI/ BRONCHIOLES
* smooth muscle, allows air to move
in and out and maintains high
concentration gradient of O2 / CO2
ALVEOLI
* thin (epithelial) wall, reduces
diffusion distance
* collagen / elastic fibres, elastic
recoil to help squeeze air out
during exhalation
* large number / provide large
surface area, to increase rate of
diffusion
* good blood supply / capillaries,
maintains high concentration
gradient
* surfactant, allows gases to
dissolve
DIAPHRAGM/ INTERCOASTAL MUSCLES
* contract to increase volume in
lungs, reduce pressure and cause
inspiration
61
which of the two diagrams, (a) or (b), represents the body immediately after expiration? describe how this diagram justifies your choice
(a) because
- lung(s) are, deflated / less inflated / small(er) / volume decreased ✔
- diaphragm is, domed / curved up / arched / not flat / relaxed ✔
- rib cage is / ribs are, in lowered position / not raised ✔
62
why can expiration be a passive process?
it does not use muscle contraction / muscles (just) relax
OR
rib cage, falls / drops (due to gravity)
OR
lungs (elastic so) will recoil ✔
63
some chemicals can act as allergens. if these allergens are inhaled, they can cause breathing problems. allergens cause the smooth muscle in the walls of the airways to contract.
suggest the effects that this muscle contraction has on ventilation.
(as lumen of airways decrease)
- reduction in (lumen) diameter of, bronchi / bronchioles ✔
- harder to exhale / more resistance to exhalation /
less air can be exhaled ✔
- more air remains in the lungs ✔
- harder to inhale / more resistance to inhalation /
less air can be inhaled ✔
- harder to ventilate / more resistance to ventilation
/ increased breathing rate / gasping ✔
64
Which of the following statements, A to D, describes inhalation?
A. ribcage moves upwards and outwards; external intercostal muscles relax; diaphragm relaxes
B. ribcage moves downwards and inwards; external intercostal muscles relax; diaphragm relaxes
C. ribcage moves upwards and outwards; external intercostal muscles contract; diaphragm contracts
D. ribcage moves downwards and inwards; external intercostal muscles contract; diaphragm contracts
C. ribcage moves upwards and outwards; external intercostal muscles contract; diaphragm contracts
65
Mean oxygen uptake rate at rest in women is around 0.020 dm3 s–1.
Using these data, the student made the following conclusion:
"My data show that being pregnant reduces rate of oxygen uptake by up to 20%"
Evaluate this claim, using the data in Fig. 16.1.
- calculated rate of oxygen uptake between 0.010 and 0.018 (dm3 s-1) ✓
- calculated reduction in rate of oxygen uptake between 10 and 50% ✓
- (claim is) correct
- a comparison of calculated rate with , 20% statement/ mean uptake / 0.020 (dm3 s-1) ✓
66
the figure below shows a light micrograph of an insect’s gas exchange system.
name the structures labelled A and B in the figure.
A - spiracle
B - trachea
67
in ventilation, water moves into the buccal cavity, across the gills and out of the opercular cavity.
complete the table by placing ticks (✓) in the appropriate boxes to show which of the processes occur at each stage of ventilation.
- water moves into the buccal
cavity
- water moves across the gills
and out of the opercular cavity
- buccal cavity floor lowers
- mouth closes, operculum opens, highest rate of oxygen diffusion into
the blood
68
A student described how they dissected a fish to view the gills:
‘I held the fish on a cutting board with one hand. I used scissors and a scalpel to carefully cut from the mouth to the tail, down the ventral side of the fish. I was able to split the fish into two halves and view the gills on the inside of the mouth.’
suggest one improvement to the student’s method that would allow them to observe the gills more easily.
- remove operculum / described (rather than cutting up the ventral side) ✓
- use pins to hold fish (rather than a hand) ✓
- remove gills and observe under a microscope ✓
69
when walking, the abdomen of caterpillars expands and contracts slowly. air is taken into the tiny holes along the side of the body. one of these holes is labelled in Fig. 16.
name these holes.
- spiracle (s) ✔
70
fluid is found in the tubes responsible for gaseous exchange in insects.
name this fluid.
- trachea(l) (fluid) ✔
71
the trachea and tracheoles of insects have circular bands of chitin. one of these bands is labelled C on the figure.
what is the function of the circular bands of chitin labelled C?
support
or
prevents the trachea(e) from collapsing / keeps the airways open ✔
72
the mites use their mouthparts to bite through the walls of the trachea. they then feed off the haemolymph, the blood-like liquid that bathes the cells and organs of the honeybee.
suggest one other way in which the presence of the mites might affect the honeybee
- (their presence) restricts the airflow in the trachea / blocks the airways
- (leakage of haemolymph) deprives the, tissues / cells, of, oxygen / O2 / nutrients
- use of, oxygen / O2 / nutrients, by mites
- disease transmission
73
fig. 1.1 shows a microscopic image of part of a fish gill.
name structure A
lamella
74
explain how Fig. 1.1 shows that gills are adapted for efficient gas exchange
- faster diffusion (of oxygen, carbon dioxide)
- many / AW, lamellae / structure A, provide large surface area (1)
- (presence of) secondary lamellae on main lamellae provide large surface area (1)
- short distance between blood and, water / outside (1)
- idea that blood maintains diffusion gradient (1)
75
each gill is supported by a gill arch made of bone. bone tissue is made of living cells, collagen and an inorganic component.
explain why bone is described as a tissue and gills are described as organs
- tissue has, one / few, types of cell and performs, one / few, functions (1)
- idea that bone has, one / few, types of cell OR idea that bone performs, one / few, functions (1)
- organs consist of several tissues (1)
- gills contain two or more named tissues (1)
76
a student planned to carry out a dissection of insect and fish gaseous exchange systems. the student planned to complete diagrams of the different tissues. they were advised to observe the following guidelines:
* use a sharp pencil
* use ruled label lines
* include a scale bar.
Suggest two further guidelines for the student to follow to ensure they present their diagrams clearly
and accurately
- large size / at least 50% of available space ✔
- title / heading ✔
- labels outside diagram ✔
- label lines should not cross over
others ✔
- continuous lines ✔
- no shading ✔
- use plain paper ✔
- state magnification ✔
- correct proportions ✔
77
bony fish and insects have different gas exchange systems. both can be observed by dissection. describe how you would carry out the dissection to display maximum detail of either gas exchange
system.
- removal of operculum (of fish) / move operculum out of the way / cut open exoskeleton (of insect) ✓
- method to, observe / display, gills / tracheae / tracheoles ✓
78
which structure, A to D, is not an example of a surface that is specialised for the purpose of gas
exchange?
A alveolus of a mammal
B plasma membrane of a unicellular protoctista
C leaf of a tobacco plant
D trachea of an insect
B plasma membrane of a unicellular protoctista
79
Which of the statements, A to D, correctly describes the way oxygen is transferred into the blood at the gills?
A - Blood and water flow in a concurrent system with a constant concentration gradient between them.
B - Blood and water flow in a countercurrent system with a constant concentration gradient between them.
C - Blood and water flow in a concurrent system with a greater concentration gradient between them at
the start of the gill lamella.
D - Blood and water flow in a countercurrent system with a greater concentration gradient between them
at the start of the gill lamella.
B - Blood and water flow in a countercurrent system with a constant concentration gradient between them
80
Which of the options, A to D, is the correct order of surface area to volume ratios for the different mammals, arranged from the largest to the smallest?
A - Oryctolagus, Rattus, Equus, Mus
B - Mus, Rattus, Oryctolagus, Equus
C - Mus, Oryctolagus, Rattus, Equus
D - Equus, Mus, Oryctolagus, Rattus
C Mus, Oryctolagus, Rattus, Equus
81
which of the following statements, A to D, correctly explains a feature of an efficient gaseous exchange surface?
A - the layers are thin for a short diffusion distance.
B - there is a good blood supply, so the system reaches equilibrium quickly.
C - there is an increased surface area to reduce surface area to volume ratio.
D - ventilation takes place to reduce concentration gradient of dissolved gases
A - the layers are thin for a short diffusion distance.
82
ventilation is a process that involves various parts of the body. which of the following options, A to D, describes exhalation in a mammal?
A - ribcage moves upwards and outwards; external intercostal muscles relax; diaphragm relaxes
B - ribcage moves downwards and inwards; external intercostal muscles relax; diaphragm relaxes
C - ribcage moves upwards and outwards; external intercostal muscles contract; diaphragm relaxes
D - ribcage moves downwards and inwards; external intercostal muscles contract; diaphragm contracts
B - ribcage moves downwards and inwards; external intercostal muscles relax; diaphragm relaxes
83
which of the following muscles in the mammalian ventilation system contract to force air out of the lungs?
A - all of the muscles in the mammalian ventilation system
B - the external intercostal muscles
C - the diaphragm
D - the internal intercostal muscles
D - the internal intercostal muscles
84
air moves in and out of human lungs through the trachea, which is lined with cells. the diagram below shows
a section containing these cells. which of the following statements about tracheal cells is correct?
A - Cells X, Y and Z are all columnar epithelial cells
B - Cells X and Y move mucus and trapped bacteria out of the trachea
C - Cell X releases mucus into the trachea
D - Cell Z is a goblet cell
C - Cell X releases mucus into the trachea
85
the graph in Fig. 8.1 shows a normal spirometer trace.
which option correctly describes what is happening at point Z?
A - pressure inside lungs is low
B - volume of thorax is large
C - diaphragm is contracted
D - internal intercostal muscles are contracted
D - internal intercostal muscles are contracted
