• Before?a (parent) cell?divides, it needs to?copy the DNA?contained within it
  • This is so that the two new (daughter) cells produced will both receive the?full copies of the parental DNA

   

• The DNA is copied via a process known as?semi-conservative replication?(semi = half)
  • The process is called so because?in each new DNA molecule?produced, one of the polynucleotide DNA strands (half?of the new DNA molecule) is?from the original DNA molecule?being copied
  • The other polynucleotide DNA strand (the other half of the new DNA molecule) has to be newly created by the cell
  • Therefore, the new DNA molecule has?conserved half?of the original DNA and then used this to create a new strand

   

The importance of retaining one original DNA strand

• It?ensures?there is?genetic continuity?between generations of cells
• In other words, it ensures that the new cells produced during cell division?inherit all their genes?from their parent cells
• This is important because cells in our body are?replaced regularly?and therefore we need the new cells to be able to do the same role as the old ones
  • Replication of DNA and cell division also occurs during?growth

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