wasps

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wasps

by dreamv » Mon Feb 20, 2012 7:13 pm
Parasitic wasps lay their eggs directly into the eggs of various host insects in exactly the right numbers for any suitable size of host egg. If they laid too many eggs in a host egg, the developing wasp larvae would compete with any other to the death for nutrients and space. If too few eggs were laid, portions of the host egg would decay, killing the wasp larvae.

Which of the following conclusions can properly be drawn from the information above?

A. The size of the smallest host egg that a wasp could theoretically parasitize can be determined from the wasp's egg-laying behavior.

B. Host insects lack any effective defenses against the form of predation practiced by parasitic wasps.

C. Parasitic wasps learn from experienc how many eggs to lay into the eggs of different host species.

D. Failure to lay enough eggs would lead to the death of the developing wasp larvae more quickly than would laying too many eggs.

E. Parasitic wasps use visual clues to calculate the size of host egg.
Source: — Critical Reasoning |

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by amahapatra » Mon Feb 20, 2012 8:21 pm
THe answer will be A.

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by karthikgmat » Mon Feb 20, 2012 10:00 pm
Not sure between D and A.

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by dreamv » Tue Feb 21, 2012 12:53 pm
Could you explain why A? What does "the size of the smallest egg" play a role here?

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by pemdas » Tue Feb 21, 2012 3:40 pm
B looked good for me initially, but it's not quite conclusion for parasites here, hence the only option by OPE is a) which theoretically describes the likely process - Why not?

a
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by pemdas » Tue Feb 21, 2012 3:42 pm
dreamv wrote:Could you explain why A? What does "the size of the smallest egg" play a role here?
size of the smallest egg is the least possible space considered for successful laying of parasitis eggs.
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by dreamv » Tue Feb 21, 2012 7:29 pm
Thanks. OA is A.

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by mankey » Wed Feb 22, 2012 10:55 am
Some expert, please help here with the reasoning.

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by chris@magoosh » Wed Feb 22, 2012 2:28 pm
I like this question :). It is a tricky one.

So basically, the wasp always know the right number of eggs to lay for any given size of egg. Too many eggs, and the wasps gobble each other up; too few, and the host destroys the wasp.

Let's say we see a wasp lay 100 larvae in one host egg. Then we see another wasp lay only 50 larvae in a different host egg. We can definitely say the first egg is larger. Remember, the wasp always knows to lay just the right number based on the size of the egg. The more wasp eggs laid, the bigger the host egg.

Therefore, if we want to figure out what the smallest possible host egg a wasp could parasitize, we would observe wasps. Their egg laying behavior, i.e. how many eggs they lay, can tell us the size of the egg. So if we observe wasps and realize that they can never lay fewer than 20 wasp eggs in one host egg, then we know the smallest possible host egg would be one that accommodates 20 wasp eggs.

Hope that took the "sting" out of the problem :).