Helix

Here, the DNA molecule to be copied is shown as a double helix. As the helix separates, or unzips, complementary nucleotides are added to each template strand by DNA polymerase until two identical double helices are formed from the original double helix. For simplicity, this illustration shows the synthesis of both new DNA strands occurring with equal speeds and in the same direction. However, it should be noted that in living cells, replication of a DNA double helix proceeds with a leading strand and a lagging strand which are assembled in opposite directions and at different speeds.

Question 1: In replication of a DNA double helix, a ________ strand and a _________ strand are assembled in opposite directions and at different speeds.
  1. leading, lagging
  2. upstream, downstream
  3. forwards, backwards
  4. backwards, forwards


Answer 1

Answer - (a) leading, lagging