Scientists analyzing air bubbles

Answer choices

1. A

   No Impact11% picked this

   Diatoms are a microscopic form of algae that has remained largely unchanged since the

   Diatoms are just one example of Antarctic algae; the scientist isn't especially concerned with diatoms. Whether diatoms have changed or not changed since the last ice age has no bearing on this conversation.

   11%
2. B

   Strengthens1% picked this

   Computer models suggest that a large increase in ferrous material today could greatly promote the

   This makes the author's hypothesis sound more plausible, since it corroborates the link between high ferrous and more algae.

   1%
3. C

   No Impact23% picked this

   The dust found in the air bubbles trapped in Antarctic ice contained other minerals in addition

   I don't think we were ever assuming that the dust was pure ferrous material. It doesn't change anything to learn that there were other minerals in there too. The existence of other minerals in the air bubble doesn't suddenly become an alternate explanation for why there was high ferrous and low CO2 in the ancient atmosphere.

   23%
4. D

   Correct61% picked this

   Sediment from the ocean floor near Antarctica reflects no increase, during the last ice age, in the rate at which the shells that

   Why this is right

   This hurts the plausibility of the author's story. The author thought: more ferrous, more algae (f.e. diatoms), less CO2 If there were more Antarctic algae such as diatoms during this last ice age, then we would expect to find more diatom shells in the sediment of the ocean floor. If we're not finding more diatom shells, then it doesn't seem like there were more diatoms during that time period, which makes the scientist's hypothesis seem a bit less convincing.

   Skill tested: Weaken · how this choice captures the argument's function is the move to repeat next time.

   61%
5. E

   No Impact4% picked this

   Algae that currently grow in the oceans near Antarctica do not appear to be harmed by even a large increase

   The storyline never involved the algae being harmed by ferrous material; to the contrary, the scientist thought that ferrous material promoted more algae. So, if anything, this answer goes with the hypothesis, not against it.

   4%