The average size of a living organism

Question

The average size of a living organism on a planet is inversely proportional to the net downward force exerted on the organism. This is the reason that large planets with high levels of gravitational force typically harbor organisms of the smallest sizes. However, a recent study concluded that Xandar, one of the larger planets with a large gravitational force, if habitable, would create an ecosystem that would breed extremely large organisms.

Which statement below best explains the contrast above?

A. Calcium deposits found in the water of Xandar will lead to stronger bones of the organisms.
B. Nidavellir, a planet 5% larger than Xandar, has shown evidence of supporting extremely large organisms.
C. Xandar is covered with nitrogen, the primary content in fertilizer, and hence will support the growth of rich flora.
D. Since Xandar is completely covered in water, the buoyant force of water will counter the gravitational force, reducing the overall net force acting on the organism.
E. Scientists claim that Xandar will support the growth of smallest 4-legged micro-organism ever seen.

arun6765 · Answer

IMO ans should be D.

Only D according to me resolve paradox since downward pull of gravity is counteracted by upward buoyant force of water.
So D logically explain why ecosystem on planet Xandar will breed extremely tall organisms.

globaldesi · Answer

A. Calcium deposits found in the water of Xandar will lead to stronger bones of the organisms.  Stronger bones do not lead to large creatures. 
B. Nidavellir, a planet 5% larger than Xandar, has shown evidence of supporting extremely large organisms.  It gives evidence supporting but does not explain the controversy. 
C. Xandar is covered with nitrogen, the primary content in fertilizer, and hence will support the growth of rich flora. nitrogen will not counter the effects of gravitational push 
D. Since Xandar is completely covered in water, the buoyant force of water will counter the gravitational force, reducing the overall net force acting on the organism. It explains counter force balancing the gravitation. this choice also resolves the paradox. 
E. Scientists claim that Xandar will support the growth of smallest 4-legged micro-organism ever seen. Again no relevance with the paradox

priyabratg · Answer

Premise: More net downward force -> less average size.So large planets with high gravity(downward net force) harbor smallest sizes organisms. Paradox: Though Xandor is one of the larger planets with high gravitational force,it has potential to breed extremely large organisms.(opposite to logic in premise). We need to look for an option which will explain the paradox. Option D does this job quite well since it says that,though gravitational force is high,net downward force is low since buoyant force of water counters gravity. Mathematically, net downward force=Gravitational force - Buoyant Force. Hope my understanding is correct. Please share Kudos

redskull1 · Answer

D is right...for the reasons stated above...but nidavellir,xandar had me purring as a marvel fan

Posted from my mobile device

SajjitaKundu · Answer

As stated by everyone above, only D helps in resolving the apparent discripancy.

CrackverbalGMAT · Answer

This is an Explain/Resolve the Paradox type of question.

The contrast mentioned is that large planets with high levels of gravitational force typically harbor organisms of the smallest sizes but a recent study concluded that Xandar, one of the larger planets with a large gravitational force, if habitable, would create an ecosystem that would breed extremely large organisms. We are looking for an option to explain why Xandar would create an ecosystem that would breed large organisms.

Option A mentions strong bones, but merely having strong bones does not explain why the organisms will be large. Even smaller organisms can have strong bones. So, Option A can be eliminated.

Nidavellir is another planet altogether but that doesn’t explain why either of the planets is able to support large organisms. So, Option B can be eliminated.

Option C gives information to show why rich flora can grow on the planet, but does not connect the information to extremely large organisms. So, Option C can be eliminated.

Option E provides information to support a contradictory statement from the one made in the passage. We need information to show why it can support extremely large organisms. So, Option E can be eliminated.

Option D provides information that can be connected back to the first sentence of the argument – “The average size of a living organism on a planet is inversely proportional to the net downward force exerted on the organism.” 
If the buoyant force of water will counter the gravitational force, reducing the overall net force acting on the organism, the planet would be able to support extremely large orgnisms. 
 Therefore, D is the most appropriate option.

Jayanthi Kumar.

The average size of a living organism

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The average size of a living organism

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