PDF800 SET8 Question 33

zozo123 · Posted: Sat Jul 28, 2007 4:51 am Post subject: PDF800 SET8 Question 33

In order to withstand tidal currents, juvenile horseshoe crabs frequently burrow in the sand. Such burrowing discourages barnacles from clinging to their shells. When fully grown, however, the crabs can readily withstand tidal currents without burrowing, and thus they acquire substantial populations of barnacles. Surprisingly, in areas where tidal currents are very weak, juvenile horseshoe crabs are found not to have significant
barnacle populations, even though they seldom burrow.

Which of the following, if true, most helps to explain the surprising finding?

A. Tidal currents do not themselves dislodge barnacles from the shells of horseshoe crabs.

B. Barnacles most readily attach themselves to horseshoe crabs in areas where tidal currents are weakest.

C. The strength of the tidal currents in a given location varies widely over the course of a day.

D. A very large barnacle population can significantly decrease the ability of a horseshoe crab to find food.

E. Until they are fully grown, horseshoe crabs shed their shells and grow new ones several times a year

saurabh_1922@yahoo.co.in · Posted: Sat Jul 28, 2007 4:04 pm Post subject: PDF800 SET8 Question 33

Acording to me answer should be E.The area where tidal currents are weak,the juvenile crabs do not have significant Barnacles.So if you consider E as correct option that justifies the less barnacle population.If juvenile crabs keep shedding the shells,the barnacle population will be low.
According to me C and D are out of scope.If you consider A ,it doesnt help justify the surprise finding.If Tidal currents do not dislodge barnacles fromthe shell of crabs,it means Tidal currents have no effect on barnacles.And as it is mentioned that it seldom burrows in that low tide area it should increase the population.

If you consider B as correct it doesnt support the surprise findings.If barnacles attach themselves in low tide areas,its population should increase and not decrease as mentioned.

So the answer should be E.
Please let us know the correct answer as I have provided teh answer based on my reasoning which may oy may not be correct

zozo123 · Posted: Sun Jul 29, 2007 1:07 am Post subject:

The OS is E. Congratulations