3 mins 9 secs and all correct. Fairly straightforward and small passage.
Summary:
Since Hawaii is not directly connected to any land mass, plants there must have got there due to long-distance dispersal of seeds, which requires both transport & equivalence in ecology in Hawaii & places where the seeds are coming from. The author goes on to discard two theories of transport ( by ocean currents and air currents) and goes on to credit the long-distance dispersal to birds ( internal by eating fruits and excreting the seeds and external by getting stuck to feathers) who help the process.
The central idea of the passage is required to answer this question which has been emboldened in the summary.The author of the passage is primarily concerned with (A) discussing different approaches biologists have taken to testing theories about the distribution of plants in Hawaii
Testing theories is not undertaken. Discard.(B) discussing different theories about the transport of plant seeds to Hawaii
Bingo - Different theories are discussed in the passage.(C) discussing the extent to which air currents are responsible for the dispersal of plant seeds to Hawaii
Too specific to be the main idea of the passage. Discard.(D) resolving a dispute about the adaptability of plant seeds to bird transport
There is no dispute underlined in the passage. Discard.(E) resolving a dispute about the ability of birds to carry plant seeds long distances
Discard for the reason stated above.Detail question, straightforward.The author mentions the results of flotation experiments on plant seeds most probably in order to (A) support the claim that the distribution of plants in Hawaii is the result of the long-distance dispersal of seeds
TRAP - a lot of words from the passage but put out of context here. Discard.(B) lend credibility to the thesis that air currents provide a method of transport for plant seeds to Hawaii
Nah. Flotation exercise was to disprove ocean current theory (C) suggest that the long-distance dispersal of seeds is a process that requires long periods of time.
Laughably irrelevant to the question. Discard. (D) challenge the claim that ocean currents are responsible for the transport of plant seeds to Hawaii
Bingo - exactly what we are looking for.(E) refute the claim that Hawaiian flora evolved independently from flora in other parts of the world
Out of scope of mentioned experiments. Discard.Inference type requiring application of info from passage to an external new situation It can be inferred from information in the passage that the existence in alpine regions of Hawaii of a plant species that also grows in the southwestern United States would justify which of the following conclusions? (A) The ecology of the southwestern United States is similar in important respects to the ecology of alpine regions of Hawaii.
BINGO - verbatim from the first paragraph of the passage(B) There are ocean currents that flow from the southwestern United States to Hawaii.
Absurd to even consider this. Discard.(C) The plant species discovered in Hawaii must have traveled from the southwestern United States only very recently.
Very recently? Irrelevant to discussion and cannot be inferred. Discard.(D) The plant species discovered in Hawaii reached there by attaching to the feathers of birds migrating from the southwestern United States.
A possibility but for inference we have to give 100% support for the option and this is not the case here. Discard.(E) The plant species discovered in Hawaii is especially well adapted to transport over long distances.
Discard - not related to the specific question at hand.Again a question related to the main idea of the passage. Trickiest of the lot.The passage supplies information for answering which of the following questions? (A) Why does successful long-distance dispersal of plant seeds require an equivalence between the ecology of the source area and that of the recipient area?
TRAP - two ideas from the passage but mutually unrelated. Discard.(B) Why are more varieties of plant seeds adapted to external rather than to internal bird transport?
No information is given as to "why" this happens but this fact is mentioned. So another trap. Discard.(C) What varieties of plant seeds are birds that fly long distances most likely to swallow?
The varieties are not mentioned. Discard. (D) What is a reason for accepting the long-distance dispersal of plant seeds as an explanation for the origin of Hawaiian flora?
BINGO - even if this isn't apparent at first sight - the first line of the passage talks about why we need this theory to explain the diverse flora of Hawaii - it is not connected to any other land mass directly.(E) What evidence do biologists cite to argue that ocean and air currents are responsible for the transport of plant seeds to Hawaii?
No evidence is given in support of the two theories. Discard.Hope my explanations are helpful.