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Question 20

DNA is often drawn as a twisted ladder. What forms one rung of that ladder?

  1. A single base on its own
  2. One whole gene
  3. One complete strand running the whole length
  4. A pair of bases joined across the strandsCorrect answer

Explanation

A rung reaches from one strand across to the other, so it takes two bases, one supplied by each strand and joined in the middle. A single base cannot span that gap, and a gene is a long run of many rungs rather than one of them.

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Question 20: DNA is often drawn as a twisted ladder. What forms one rung… · Genetics Basics · Questena