Question

biology unit 2: dna, proteins, & cell division practice name: _ lesson 1: dna replication 2.) show the process of dna replication by drawing new dna strands (leading and lagging) and label the diagram. include labels for the following in the correct place: original dna, leading strand, lagging strand, 3 (for original, leading, and lagging), 5 (for original, leading, and lagging), helicase, ligase, dna polymerase, primase, enzymes

Explanation:

DNA replication involves the unwinding of the double - helix by helicase. Primase synthesizes short RNA primers. DNA polymerase adds nucleotides to the growing strands. The leading strand is synthesized continuously, while the lagging strand is made in Okazaki fragments which are joined by ligase. Label the original DNA strands, leading and lagging strands with their 3' and 5' ends, and the enzymes (helicase, primase, DNA polymerase, ligase) on the diagram.

Answer:

1. Draw the original DNA strands as a double - helix.
2. Unwind the double - helix at a point to show the replication fork.
3. Label the 3' and 5' ends of the original DNA strands.
4. On the leading strand side, show continuous synthesis of the new strand by DNA polymerase moving in the 5' to 3' direction. Label the leading strand.
5. On the lagging strand side, show Okazaki fragments being synthesized in the 5' to 3' direction away from the replication fork. Label the lagging strand.
6. Place labels for helicase at the replication fork where it unwinds the DNA.
7. Place labels for primase where it synthesizes RNA primers.
8. Place labels for DNA polymerase on both the leading and lagging strands where it adds nucleotides.
9. Place a label for ligase where it joins the Okazaki fragments on the lagging strand.