biology alevel exam question

Ann2004

explain the advantage for larger animals based on having specialised system that facilitates oxygen uptake?

Reply 1

bl0bf1sh

what do you think? what have you got so far?

Reply 2

BlueChicken

Original post by Ann2004

explain the advantage for larger animals based on having specialised system that facilitates oxygen uptake?

Consider - do larger animals have a different oxygen need than smaller ones? If so, how do they meet those needs?

Reply 3

Ann2004

Original post by BlueChicken

Consider - do larger animals have a different oxygen need than smaller ones? If so, how do they meet those needs?

so far i have
Animals respire mostly by aerobic respiration. Aerobic respiration uses oxygen, taken from air and the cells produce energy which is used by these animals to live .When their respiratory system is not efficient, it means that they are not getting sufficient energy to live. So to get enough energy to survive, these large animals require efficient respiratory system.
and bigger animals need more oxygen to respire and they have a small volume sa to volume ratio
but i dont know if this would be accepted by the mark scheme as i dont have it for aqa

(edited 2 years ago)

Reply 4

BlueChicken

Original post by Ann2004

That is good - therefore, to conclude, what is the "advantage for larger animals based on having specialised system that facilitates oxygen uptake?". Make sure you answer the specific question, which here asks about the "specialised system :undefined:

". What would the specialised system mean for the larger animal? Why do they need a specialised system? Why is the SA/volume ratio important?

Unless it's the really recent paper, all AQA mark schemes are on their web site along with examiners' reports, which explain where people went wrong. Also, questions/themes come up again and again, so I'd take a look at them all, as even if the recent one isn't available, it has probably been covered previously.

(edited 2 years ago)

Reply 5

Ann2004

Original post by BlueChicken

they are able to respire easily in order to survive
they have a double circulatory sytem where alveoli allow for a efficient gas exchange
larger organisms tend to have higher metabolic demands as they are more active. Furthermore, there are large distances required for oxygen to diffuse

(edited 2 years ago)

Reply 6

BlueChicken

Original post by Ann2004

yes - and what would it mean if they didn't have that specialised system? Could they take in air though their surface, say, like smaller organisms, sufficient for their respiratory needs? Think about diffusion pathways and where the oxygen is needed (and speed of getting to where it's needed).

Why do alveoli allow for efficient gas exchange? I would mention short diffusion pathway and large exchange surface area and why that is an advantage. You could also mention concentration gradients.

You need to cover what the adaptations are and why they are an advantage. Have in mind what section of the specification this relates to.

I think that would be all the points to cover (I am sure someone will reply if I've missed something). Hope that helps. Good luck.

Mark schemes: https://www.aqa.org.uk/find-past-papers-and-mark-schemes