uni q's

[jaja]

hey everyone!
im in first year uni doing behavioural neurscience
just a few questions on a prac thats due tomorrow
 
"compared to a frog what would you predict about the circulatory, respiratory and excretory systems of a bird or mammal/"

"which animal requires more oxygen, a 5gm mouse or a 5kg dog?"

"which requires more oxygen, one thousand 5gm mice or one 5kg dog? why?"

thanks in advance

[lexitu]

Not sure about the frog one because i don't know enough about them.

Obviously a 5kg dog will need more oxygen. However in the next example the 5kg dog will need less than the 1000kg mice because it has a lower surface area to volume ratio. This means that it is better able to use energy because less heat is lost from its skin surface. The mice being relatively smaller would expend more energy (and hence use more oxygen) to produce heat that keeps their metabolic rate up. Unless mice have a special system, this should be true.

[jaja]

ahh thanks for that.. i completly forgot about it.
for the frog question this is the additional information they gave us.
"Birds and mammals are very active and maintain a constant and high rate of metabolic activity in their cells compared with frogs, which have a metabolic rate that varies to some extent with envionmental temperature"
so i persume the frog question has something to do with metabolic rate?

[lexitu]

No worries

Umm yeah it should have something to do with metabolic rate, I can't really think of what exactly differs. I remember doing something in year 11 though... Frogs definitely have a different excretory system (they have a cloaca haha), but sorry can't help you.

Good luck though