surface area to volume ratio and gas exchange

Question 1

larger organism need specialised exchange surfaces

Answer 1

greater demand for materials and produce more waste

waste needs to be removed rapidly

heat needs to be dissipated to prevent overheating

to prevent denaturation of enzyme

cells are distant from the external environment - materials need to travel together

Question 2

efficient exchange surface

Answer 2

large surface area
thin
steep concentration gradient - constant supply of materials to be exchanged on one side
keep concentration high and constant removal on the other side

Question 3

organisms metabolic rate

Answer 3

amount of energy expended by the organism in a time period
- usually daily

Question 4

metabolic demand

Answer 4

how much oxygen and nutrients an organism need to take in daily to respire enough to maintain metabolic rate

Question 5

unicellular organism

Answer 5

large sa:v
diffusion distance is short
advantage
exchange materials directly with their environment
disadvantage
lose heat energy and water quickly
cannot survive extreme heat or cold

Question 6

multicellular organism

Answer 6

small sa : v cannot absorb enough substance to supply a large volume through a smaller outer surface

diffusion distance is large to get from outside to all cells in the centre organism

advantage
lose less energy as heat so Can survive more easily

disadvantage
some cells will have no surface exposed to outside so need internal mass transport systems . In not environment

Question 7

structures in lungs

Answer 7

lung
larynx
trachea
bronchus
bronchioles
external intercostal muscle
internal intercostal muscle
ribs
diaper