Question

What happens when DNA Replication does not occur?

Answer 1

DNA or Deoxy-Ribonucleic Acid is the genetic material in most of the higher organisms. It carries out the genetic control of all physiological functions such as reproduction, growth, development, etc. Many viruses also have DNA as their genetic material.

Complete answer:
DNA replication is a stage involved in the cell cycle leading to cell division. During replication, the genome within the cells, that is, the DNA gets duplicated to form another copy of the same. By this process the daughter cells produced as a result have identical genetic make-up. This process takes place in the S Phase of the Cell cycle. And is a very highly regulated process. Any disruption in the process of replication of the cell cycle does not move on to the next phase, inhibiting cell division. And eventually leads to cell death.

The process of replication is controlled by enzymes. The main enzyme involved in the process is DNA Polymerase. Other enzymes involved are Helicase and DNA ligase. DNA Replication in animals occurs at a greater rate in the foetal stage compared to the adult stage. The reason being, high rate of cell division during the foetal stage.

Thus if DNA replication does not occur, then the cell cycle will not proceed to the next stage and the subsequent division will not happen. It will lead to cell death.

Note: The different enzymes involved in DNA Replication along with its functions are:
i) Helicase: Unzipping or uncoiling the two DNA strands. The process occurs by breaking the weak Hydrogen bonds in between the two strands.
ii) DNA Polymerase III: Addition of new nucleotides to the 3’ terminal of the original parent strand. Helps in producing leading strands.
iii) DNA Polymerase I: Removal of attached Primer.