Gas Exchange Flashcards
- Why does an organism need oxygen? For that to happen what do organisms need?
respiration = atp = respiratory surface
- What are the properties of respiratory surfaces? (5)
thin = short diff pathway moist = dissolves gasses permeable = gases thru good blood supply = diff grad large SA
- Why does amoeba not require adaptations?
low energy demand and large SA:V ratio
- How does amoeba carry out gas exchange?
simple diffusion
5.What is principle of SA to volume ratio? Calc SA area surface area volume
Size of organism increases, SA:V decreases
meaning there is small diff pathway which increases metabolic rate
a = bxh
sa = ax6
v= lxwxh
- Does volume or surface area increase quicker, which means that adaptations are needed?
Volume increases quicker so adaptations needed
- How does an earthworm increase its SA?
by having tubular shape
- Where does earthworm live? Adaptation?
lives on land = keep epidermis moist by secreting mucus
- What does adaption provide and where do earthworms tend to stay?
little protection from desiccation so earthworms stay in moist conditions
- How does earthworm carry out gas exchange?
diffusion across epidermis
- Why is it good that an earthworm has a tubular shape?
for high SA:V ratio
- How does an earthworm increase efficiency of gas exchange?
capillary network and haemoglobin blood pigment = increases efficiency of GE
- What other adaptations does an earthworm need? (3)
low metabolic rate
moist
flattened shape
- If SA:V falls below a value, what happens?
GE cant happen fast enough to supply organism’s needs
- What have larger organisms had to evolve?
systems and organs
- Tadpoles are aquatic, so what do they use for GE?
gills
- What does an inactive frog use for GE?
moist skin for GE
- What does an active frog use for GE?
simple internal lungs
- Why does crocodile need no GE?
no ge thru skin bc reptiles are scaly
- What adaptations does crocodile have? (2)
more efficient lungs than amphibians
rib cage to assist with ventilation and protect organs in body cavity
- Why do birds have a higher energy demand than reptiles?
homeothermic
- How do gills maximise rate of diffusion? (4)
- filament and llamelae = large SA
- thin epithelium = short diffusion pathway
- rich supply of blood vessels = transport gases to and from surface
- ventilation mechanism to maintain conc grad
