In experiments in which certain kinds

Answer choices

1. A

   Correct43% picked this

   Either all genetic mutations are random or none

   Why this is right

   This performs the service we needed: "if bacteria's mutations are random, then all mutation is random." But it does so in a funky way. Whenever we say "either X or Y", we're saying at least one of those ideas is true. In the case of mutually exclusive options, such as "All A's are B / No A's are B", they can't both be true, so exactly one of them is true. It's impossible for "No genetic mutations are random" to be true, because we were told in the evidence that genetic mutations are random within populations of bacteria. So then it must be true that "All genetic mutations are random", which means the conclusion is proven true. This answer alone doesn't prove the conclusion, but this answer combined with our evidence proves the conclusion. Answer: mutations are X or Y Premise: mutations are not Y. Conclusion: mutations are X. X = all random Y = all not-random

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

   43%
2. B

   Too Weak2% picked this

   The bacteria tested in the experiments were of extremely

   Learning that this bacteria was an extremely common type makes us optimistic that "if these bacteria had random mutations, then most bacteria probably have random mutations". But it wouldn't get us anywhere close to proving that "all genetic mutation (in any species) is random".

   2%
3. C

   Bad Trigger Match31% picked this

   If all genetic mutations in bacteria are random, then all genetic mutations in every other life

   This answer is very tempting, because it gives us a rule like this: If all genetic mutations ? then all mutations in bacteria are random in other life forms are random If we could trigger that rule then we would certainly get an outcome that proves the conclusion. But can we trigger this rule? Do we know that all genetic mutations in bacteria are random? No, we only know that within experiments, certain kinds of bacteria showed random genetic mutations. Since we don't know yet whether all bacteria have nothing but random genetic mutations, we can't trigger this rule, and so it goes nowhere.

   31%
4. D

   Unrelated to Goal19% picked this

   The kind of environment in which genetic mutation takes place has no effect on the

   This has no language resembling our conclusion "all genetic mutation is random", and it does nothing to get us from "these bacteria had random genetic mutations" to our goal of "all genetic mutations are random".

   19%
5. E

   Unrelated to Goal5% picked this

   The nutrients used were the same as those that nourish the

   This has no language resembling our conclusion "all genetic mutation is random", and it does nothing to get us from "these bacteria had random genetic mutations" to our goal of "all genetic mutations are random".

   5%