Brainscape's Knowledge GenomeTM

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


See full index

Biology Year 12 > Gas exchange (6) > Flashcards

Gas exchange (6) Flashcards

1
Q

Why do multicellular organisms need specialised gas exchange surfaces?

A

their smaller SA:V ratio means the distance that needs to be crossed is larger + substances cannot easily enter the cells like in a single-celled organism

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

What are 3 features of efficient gas exchange?

A

1) large surface area e.g. folded membranes in mitochondria
2) thin/short distances e.g. wall of capillaries
3) stop concentration gradient, maintained by blood supply or ventilation e.g. alveoli

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

Why can’t insects use their bodies as an exchange surface?

A
  • waterproof chitin exoskeleton
  • small SA:V ratio in order to conserve water
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe gas exchange in insects.

A
  • gases move in and out of tracheae through spiracles
  • diffusion gradient allows O2 to diffuse into body tissue whilst waste CO2 diffuses out
  • contraction of muscles in the tracheae allows mass movement of air in and out
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the 3 structures in an insect’s transport system?

A

1) spiracles
2) tracheae
3) tracheoles

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

What are spiracles?

A

holes on body’s surface which may be opened or closed by a valve for gas or water exchange

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

What are tracheae?

A

large tubes extending through all body tissues, supported by rings to prevent collapse

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

What are tracheoles?

A

smaller branches dividing off the tracheae

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

Why can’t fish use their bodies as an exchange surface?

A
  • waterproof, impermeable outer membrane
  • small SA:V ratio
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the 2 features of fish gas transport systems?

A

gills
lamellae

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

What are gills and where are they found?

A
  • located within the body
  • supported by arches along which are multiple projections of gill filaments, which are stacked up in piles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are lamellae?

A

at right angles to gill filaments
increase surface area
blood + water flow across them in opposite direction

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

What’s the term used to describe blood + water flowing in opposite directions?

A

counter-current exchange system

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

What is the process of gas exchange in fish?

(3 points)

A

1) fish opens mouth to enable water to flow in, then closes its mouth to increase pressure
2) water passes over lamellae and O2 diffuses into bloodstream
3) waste CO2 diffuses into water and flows back out of the gills

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

How does the counter-current exchange system maximise O2 absorbed?

A

maintains steep concentration gradient as water is always next to blood of a lower O2 concentration, which keeps rate of diffusion constant and enables 80% of available O2 to be absorbed

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

What are 3 adaptations of leaves which allow for efficient gas exchange?

A

1) think + flat
2) many stomata
3) air spaces in mesophyll

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

How does being thin + flat allow leaves to have efficient gas exchange?

A

provide short diffusion pathway and large SA:V ratio

18
Q

How does having stomata allow leaves to have efficient gas exchange?

A

allow gases to easily enter

19
Q

What are stomata?

A

minute pores on underside of leaf

20
Q

How does having air spaces in mesophyll allow leaves to have efficient gas exchange?

A

allow gases to move around the leaf, facilitating photosynthesis

21
Q

How do plants limit water loss?

A
  • stomata regulated by guard cells which allows them to open and close as needed
  • most stomata stay closed while some open to let O2 in
22
Q

What is the order of the mammalian gaseous exchange system?

A

1) nasal cavity
2) trachea
3) bronchi
4) bronchioles
5) alveoli

23
Q

What is the function of the nasal cavity?

A
  • good blood supply warms and moistens air entering the lungs
  • goblet cells in membrane secrete mucus which traps dust and bacteria
24
Q

How do you calculate the pulmonary ventilation rate?

A

tidal volume x breathing rate

25
Q

How do you measure tidal volume and breathing rate?

A

spirometer

26
Q

What is a spirometer?

A

device that records volume change onto a graph as a person breathes

27
Q

What is the structure of the trachea?

A

wide tube supported by C-shaped cartilage
lined by ciliated epithelium cells

28
Q

Why is the trachea a wide tube supported by C-shaped cartilage?

A

to keep air passage open during pressure changes

29
Q

Why is the trachea lined by ciliated epithelium cells?

A

moves mucus towards the throat to be swallowed, preventing lung infections

30
Q

What is the function of the trachea?

A

carries air to the bronchi

31
Q

What is the structure of the bronchi?

A

like trachea, they are supported by rings of cartilage and are lined by epithelium cells, however narrower, 2 of them and 1 for each lung

32
Q

What is the function of the bronchi?

A

allow passage of air into the bronchioles

33
Q

What is the structure of the bronchioles?

A

narrower than the bronchi
don’t need to be kept open by cartilage, therefore mostly only muscle + elastic fibres so they can contract and relax easily during ventilation

34
Q

What is the function of the bronchioles?

A

allow passage of air into the alveoli

35
Q

What is the structure of alveoli?

A
  • mini air sacs lined with epithelium cells
  • walls only 1 cell thick, covered with network of capillaries
  • 300 million in each lung
36
Q

What is the function of alveoli?

A

facilitate gas exchange

37
Q

What is tidal volume?

A

volume of air we breathe in and out during each breath at rest

38
Q

What is breathing rate?

A

number of breaths we take per minute

39
Q

What happens during inspiration?

A
  • external intercostal muscles contract, pulling ribs up and out
  • internal intercostal muscles relax
  • diaphragm contracts + flattens
  • thorax volume increases
  • air pressure outside lungs is therefore higher than air pressure inside, so air moves in to rebalance
40
Q

What happens during expiration?

A
  • external intercostal muscles relax
  • internal intercostal muscles contract
  • diaphragm relaxes + domes upwards
  • thorax volume decreases
  • air pressure outside lungs is therefore lower than air pressure inside, so air moves out to rebalance

Biology Year 12 (22 decks)

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