endo/ectotherms (1 Viewer)

[NeRdY]

I am getting confused with this question. Could someone please explain it?

A small Australian mammal that lives in the alpine regions of NSW has specific features that enable it to retain body heat. identify the features that are most likely to be present in the mammal described:

a) long ears, rounded body, long legs
b) short ears, rounded body, short legs
c) short ears, slender body, long legs
d) short ears, slender body, short legs

I believe the answer is B but still could someone explain. I partisularly dont understand the SA:V ratio business.

Much appreciated!

 

[babydoll_]

OK think about it... when you're cold, aren't you more likely to curl up in a ball than to stretch yourself out?

It's because you're trying to reduce the amount of skin exposed to the cold, which therefore keeps your body warm.

So short ears would reduce amount of ear exposed to the cold... rounded body is more compact and thus, less exposure to cold... likewise with short legs.

Make sense?

 

[NeRdY]

perfect sense thanx

 

[NeRdY]

Ok i just thought of something else thats confusing me. A polar bear and a penguin as different sizes. i though the larger SA:V ratio of the bear allowed it to maintain heat but then is it an ectotherm because it hibernates??? the penguin has a smaller SA:V ration compared to the bear and whales.

 

[Shuter]

I suppose that is a somewhat vague area, it is still an endotherm, as it maintains a fairly constant temperature (although somewhat lower when hibernating), and uses fat stores to fuel this process. Ecotherms will be the same temperature as their surroundings whilst endo therms will be a different temperature (even if they do vary their temperature somewhat).

Penguines have alot of blubber to insulate them, and short feet and features.