Brainscape's Knowledge GenomeTM

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


See full index

biology paper 1 > 3.3.2 gas exchange > Flashcards

3.3.2 gas exchange Flashcards

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

what are spiracles?

A

spiracles are controlled valves that form the exit part of trachea

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

what features do insect gas exchange have?

A

thin SA
increased SA
moist surface

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

which direction does CO2 go?

A

out of cells into haemolymph and into tracheoles

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

which direction does O2 go?

A

O2 goes into the haemolymph and further into body cells

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

how do insects increase SA?

A

by having an extensive network of trachea and tracheoles

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

how does gas exchange work in insects?

A

oxygen from the air in the tracheoles dissolve into the haemolymph fluid on the thin moist membrane surface and diffuses into the cells
O2 diffuses from tracheoles into haemolymph from a high concentration of O2 to a lower concentration
CO2 (produced by respiration) can diffuse from cells into haemolymph into tracheoles from a high concentration of CO2 to a low concentration

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

what is haemolymph?

A

insect equivalent to blood

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

what are the thin membranes surrounded by?

A

water haemolymph

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

what are the ends of tracheoles lined with?

A

thin moist surface (membranes) - this is where the exchange of gases takes place

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

what does the trachea lead to?

A

trachea leads to small tracheoles

ends of each tracheole finishes in a group of body cells

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

how are insects adapted for dry habitats?

A

collapsible air sacs present in areas without taenidiae
temporary air supply allows insects to conserve water by closing its spiracles during dry periods
stored air in sacs

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

what are the trachea walls reinforced with?

A

taenidiae (thicking of the chitin)
this allows insects to flex me stretch without developing kinks that might restrict air flow

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

how do spiracles open?

A

by small muscles that contract to shut flap like valves and relax to open the valves
allows control of air flow and slows down loss of water

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

what are the openings called on the sides of an insects body?

A

spiracles linked with chitin
chitin gives shape to the openings

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

describe gas exchange in single-celled organisms

A

single-celled organisms are small and therefore have a large SA:V ratio

oxygen is absorbed by diffusion across their body surface, covered by a CSM

CO2 diffuses out across their body surface

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

how do respiratory gases move in and out of the tracheal system?

A
  1. along a diffusion gradient = diffusion gradient causing gaseous oxygen to diffuse from the atmosphere along the trachea and tracheoles to the cells
    CO2 is produced by cells during respiration which creates a diffusion gradient in the opposite direction.
  2. mass transport = contraction of muscles in insects can squeeze the trachea enabling mass movements of air in and out
  3. ends of the tracheoles are filled with water = lactate is produced through anaerobic respiration (soluble and reduces water potential)
    water moves into the cell from the tracheoles from osmosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is a limitation of the tracheal system?

A

relies mostly on diffusion so diffusion pathways need to be short which is why insects are a small size

length of diffusion pathway limits the size that insects can attain

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

what is counter current flow?

A

arrangement of water flowing past the gills in the opposite direction to the blood

means that blood is already well-loaded with oxygen therefore sufficient diffusion takes place

diffusion gradient for oxygen uptake is maintained

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

why are the gill lamella only one cell thick?

A

short diffusion distances

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

why do the gills have a good blood supply?

A

to maintain a concentration gradient

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

how are the folds supported?

A

kept supported and moist by water that is continually pumped through the mouth and over the gills

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

why do gills have numerous folds?

A

they give them a very large SA, increases SA:V ratio

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

what are the protrusions on the rows of gill filaments called?

A

gill lamellae

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

what are the stages of ventilation and gas exchange?

A

mouth opens and operculum closes

buccal floor lowers so the buccal cavity volume increases (as volume increases the pressure decreases and the water flows in)

mouth closes

buccal floor raises so pressure increases

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

what happens when the fish closes its mouth?

A

the gill lid opens and the water is forced out and over the respiratory surfaces of the gill filaments

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

how does a fish draw in water?

A

by closing the lid over its gills and closing its mouth

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

what is each gill covered by?

A

boney lid

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

what features do hydrophytes have?

A

low stomata density
stomata is on top side of the leaves

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

where do hydrophytes live?

A

in or on water

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

how do xerophytic plants overcome water loss?

A

hairy leaves
curved leaves
pitted stomata
trapped moisture

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

what features are used to prevent water loss?

A

stomata is kept closed at night
closed in bright light/ intense heat
closed when there will be excessive water loss

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

what two processes take place in the stomata?

A

gas exchange and water loss

33
Q

what is the chemical formula for malate?

A

C4H4O52-

34
Q

what is in the potassium pump hypothesis?

A

chloroplasts in guard cells, photosynthesise producing ATP

ATP used to actively transport K+ into guard cells from surrounding epidermal cells

starch used and stared in guard cells converted to malate

K+ and malate ions increase water potential so reduce water potential (more negative)

water entered by osmosis

guard cells expand on outside but less so in centre where cell wall is thicker

pore appears between guard cells = stomata

35
Q

features of the leaf for GA:

A

large surface area: room for many stomata, diffusion pathway is short

thin: different pathway is short
air spaces in spongy mesophyll: allows gases to diffuse between stomata and guard cells

water trapped in air spaces: gates can dissolve between cells

36
Q

where is the gas exchange system?

A

surface of the mesophyll cells in contact with air spaces in the leaf

37
Q

where does the majority of oxygen go?

A

diffuses out of the leaves

38
Q

how does the plant receive CO2?

A

plant gets CO2 from diffusion from the atmosphere through the leaves

39
Q

where is the carbon dioxide provided from?

A

carbon dioxide is providedby aerobic respiration for photosynthesis

40
Q

what do plants need a constant supply of?

A

sugar and oxygen

41
Q

how does the stomata open?

A

when water gets inside the guard cells the guard cells become turgid
thin walls curve open and open stomata

42
Q

how does water get inside the guard cells?

A

through osmosis

43
Q

what processes affect the opening of the stomata?

A

water availability
carbon dioxide concentration
light intensity

44
Q

when are the stomata closed?

A

when the guard cells are flaccid

45
Q

what gases moves in and out of the stomata?

A

CO2 and O2

46
Q

what are the guard cells roles?

A

they control the opening and closing of the stomata

47
Q

what are the characteristics of spongy mesophyll?

A

irregular and loosely packed
stores sugar and amino acids

48
Q

what two functions are in the vascular bundle?

A

the xylem and phloem

49
Q

what are the characteristics of the cuticle?

A

reduces water loss
waterproof

50
Q

what does the lower epidermis contain?

A

the stomata and guard cells

51
Q

what two layers does the mesophyll contain?

A

the palisade and spongy layer

52
Q

what are the characteristics of upper epidermis?

A

characteristics:
few or no chloroplasts
permits light through
single layer of cells
protects tissue

53
Q

what does a reduced surface area:volume do?

A

slower rate of diffusion (evaporation of water)
must be balanced by need to photosynthesise

54
Q

features of stomata in pits and grooves

A

traps moist air near the leaf surface
reduces water potential gradient
reduces air movement near stomata

55
Q

features of hairy leaves

A

hairs trap moist air near the leaf surface
reduces water potential gradient

56
Q

features of thick cuticle

A

some transpiration occurs through the waxy cuticle
cuticle is impermeable to water
thicker cuticle = less water can escape that way

57
Q

features of rolled up leaves

A

stomata tend to be on lower epidermis
they trap moist air near the stomata
reduces water potential gradient between leave and the air so transpiration greatly reduces
reduces air movement around stomata

58
Q

what do xerophytic plants do?

A

they reduce water loss through specific adaptations

59
Q

describe the structure and function of mammalian lungs

A

lungs = made up of a series of highly branched tubules called bronchioles, which end in tiny air sacs (alveoli)

trachea = flexible airway that is supported by rings of cartilage. cartilage prevents the trachea from collapsing as the air pressure reduces from breathing in.
tracheal walls are made up with muscle and lined with ciliated epithelium and goblet cells

bronchi = two divisions of the trachea each leading to one lung. produce mucus to trap dirt particles and have cilia that move the mucus towards the throat

bronchioles = branching subdivisions of the bronchi. lined with epithelial cells. muscle constricts to allow movement of air

alveoli = air sacs. alveolar membrane is the gas exchange surface.

60
Q

why is oxygen required in human gas exchange?

A

for respiration and the release of energy in the form of ATP

61
Q

how is oxygen absorbed into the lungs?

A

through the blood

62
Q

what is the equation of pulmonary ventilation?

A

pulmonary ventilation = tidal volume x ventilation rate

63
Q

what is pulmonary ventilation?

A

this is a measurement of the amount of air that is moved into the lungs in one minute

64
Q

what happens during exhalation?

A

internal intercostal muscles move ribs downwards and inwards

diaphragm recoils upwards

volume of the thorax increases

pressure of air in the atmosphere is lower than the pressure inside the thorax

air is forced out of the lungs

65
Q

what happens during inhalation?

A

volume of the thorax increases

pressure of air in the atmosphere is higher than the pressure inside the thorax

air is drawn in through the mouth into the lungs
external intercostal muscles move ribs upwards and outwards

diaphragm contracts (moves down)

66
Q

what are the two muscles of respiration?

A

internal intercostal muscles
external intercostal muscles

67
Q

what is inspiration or inhalation?

A

this is when air is forced into the alveoli because of the pressure of the atmosphere is greater than the pressure inside the lungs

68
Q

what is ventilation or breathing?

A

this is the process by which air is constantly moved in and out of lungs

69
Q

why is diffusion rapid?

A

RBC are slowed as they pass through pulmonary capillaries
distance between the alveoli air and RBC are flattened against the capillary wall

70
Q

why are capillaries narrow?

A

so that RBC are flattened and can squeeze through

71
Q

what surrounds alveolus?

A

a network of pulmonary capillaries linked with a single layer of endothelial cells

72
Q

what is each alveolus linked with?

A

a single layer of flattened epithelial cells

73
Q

how many alveoli is in each lung?

A

300 million

74
Q

what is ficks law?

A

diffusion is proportional to:

surface area x difference in concentration/
length of diffusion path

75
Q

what are the essential features of exchange surfaces?

A

large surface area:volume - speeds up the rate of exchange

very thin - keeps the diffusion pathway short
partially permeable - allows selective material to diffuse easily

moist - allow dissolving

76
Q

how does gas exchange happen in the alveoli?

A

air moves in and out of the alveolus

gases dissolve into the moist mucus lining
oxygen is transported until the blood and is transported around by red blood cells

carbon dioxide diffuses from blood to be exhaled

blood low in oxygen and high in carbon dioxide

77
Q

how is the concentration gradient maintained?

A

breathing and blood movement due to the heard ensure a concentration gradient

78
Q

how is the SA of alveoli and capillaries large?

A

alveoli is large due to folds
capillaries is large because there is largeSA

79
Q

why are the walls of the alveoli and capillaries very thin?

A

short diffusion distances

biology paper 1 (23 decks)

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