Advantages and disadvantages for an organism of being large

[punk rock princess]

Hi guys!

I have to write an essay on the advantages and disadvantages for an organism of being large.

I've thought of a few things such as:

Advantages

Smaller surface area so less heat loss in cold climates
Less susceptible to attack by predators
In the case of giraffes (ie. large in height), they are able to reach the more succulent leaves which are found higher up in trees

Disadvantages

Smaller surface area so less able to lose heat in hot climates
Need more nutrition
Less agile
Processes such as gas exchange in the lungs take longer as the gases have to diffuse over a longer distance

I'd be really grateful if anyone could help me come up with a few more ideas, and correct any of these ones if they're wrong.

Thanks

[victor]

I have an opinion like this:
some bigger organisms have bigger cells. let's analyse this.
If we imagine that cells are cube-shaped like matter with each side is 1 m length..(imagine, not real) then it's volume is 1 m3 and the coverage area is 6 m2.
second, if we take another cube-shaped like cell with each side is 2 m length..then it's volume 8 m3 while the coverage area is 24 m2.
From these comparison, let's see between both volume and coverage area for both 'cell'.
So, the conclusion is...for cell stage organisms, being small is better..

[mith]

Not quite sure you can put less vulnerable to predators, veloceraptors take down even the largest of dinosaurs. There's less a chance of it being stepped upon but size isn't really that impressive(except for the puffer fish).

[MrMistery]

Not quite sure you can put less vulnerable to predators, veloceraptors take down even the largest of dinosaurs. There's less a chance of it being stepped upon but size isn't really that impressive(except for the puffer fish).

Actually Dave(and yes, I am just being picky here) there was a time when the earth was ruled by big creatures: the age of the sauropods. Any good palentology book will tell you that giants like Diplodoccus, Seismosaurus and Brachiosaurus had no enemies after reaching a certain size. They were simply to big to take down, even by much more cunning and agile predators like Raptors.
How about a contemporary example: how many mature blue wales have you seen running from sharks?

Your ideas are all fine. If i were you i would put an ending that says there is no actual recepie for succes and biology is all about adaptation. Some environments favour the lrage, some favour the small etc. Your teachers might like it

[punk rock princess]

Need more nutrition

Just thought I'd correct myself on this. Realised that larger animals actually need less nutrition than small animals. This is linked to the fact that small animals have a larger surface area, and lose more heat. To make up for this heat loss, they must have a high metabolic rate, so they need lots of nutrition. Examples of small animals which need lots of nutrition because of this are hummingbirds and shrews.



P.S. Thanks for the advice on the ending