Question 1
According to the passage, how do the other scientists support their claim?
They argue that DNA from 17-million-year-old leaves is a modern contaminant because DNA decays too quickly, and because the leaves were trapped in wet deposits — making survival of DNA unlikely.
A. Wrong – They didn’t have DNA sequence data showing structural differences; the debate is about plausibility, not comparison.
B. Wrong – The small quantity isn’t mentioned as evidence.
C. Correct – They cited wet deposits as a reason DNA couldn’t survive.
D. Wrong – They don’t mention proven contaminants, only the possibility of contamination.
E. Wrong – No discussion of other biological relics as evidence here.
Question 2
What does the passage suggest about “the most favorable conditions”?
The critics argue that even under the most favorable conditions, DNA couldn’t survive that long. They add that because the deposit was wet, conditions were particularly unfavorable. Hence, favorable conditions likely involve dryness, not moisture.
A. Wrong – The Idaho deposit is given as unfavorable, not favorable.
B. Correct – Since wet conditions are bad, dry conditions must be part of the favorable ones.
C. Wrong – The passage doesn’t distinguish between plant and animal fossils.
D. Wrong – Favorable conditions weren’t linked to the extinct animal case.
E. Wrong – Fragment vs. intact fossils isn’t discussed as a preservation factor.
Question 3
What is true about the DNA extracted from museum specimens of an extinct animal?
That DNA was successfully extracted, but described as tiny fragments, not full strands — still sufficient to compare with modern DNA.
A. Wrong – It says most recovered DNA is fragmented, not more complete.
B. Wrong – The fragments are useful for comparison, so not too little.
C. Correct – They’re fragments, so less informative than full living DNA.
D. Wrong – Nothing says the degradation equals that in 17-million-year fossils.
E. Wrong – There’s no questioning of authenticity for the museum specimens.