Gas Exchange Flashcards
List details of Ameoba
- protoctista
- unicellular
- large SA to V ratio
- thin cell membrane
- short diffusion pathway
List details of Flatworms
- aquatic
- shape for very large SA
- short diffusion pathway
List details of earhtworms
- terrestrial
- SA to V ratio is smaller than flatworm
- skin = respiratory surface
- low requirement for oxygen
- pigment haemoglobin
Define ventilation
Bringing gases to or from gas exchange surfaces
Define Gas exchange
Process of which gases cross a gas exchange surface
Define respiration
The metabolic pathway that realeases chemical energy from food molecules
How do amphibians exchange gas?
resting = moist skin
active = lungs and moist skin
How do birds exchange gas?
- no diaphram
- large V of O2 processes
How do reptiles exchange gas?
lungs and more complex internal structures
What does a spiracle do for insects gas exchange?
opens and closes to allow diffusion and to prevent water loss
(holes in skin)
What do tracheoes do as a part of insects gas exchange?
they are moist and air is pumped in and out of them by the insect to maintain a conc gradient
(tiny tubes permeable to gas, connects spiracles and muscles)
Describe fish gills
- fish get O2 from water
- stacked to increase SA
- reduce the diffusion pathway
Describe the ventilation mechanism of a fish
water flows in mouth opens
water flows out mouth closes
water flows in operculum closes
water flows out operculum opens
water flows in floor of buccal cavity lowers
water flows out floor of buccal cavity raises
water flows in volume increases
water flows out volume decreases
water flows in pressure decreases
water flows in pressure increases
What is a countercurrent flow?
- water and blood flow across gills in opposite directions
- always a conc gradient
What is the main gas exchange organ in a plant?
Leaves - also site of photosynthesis
