Question

Describe what you think would happen to a cell that was missing the ligase enzyme and tried to replicate its DNA? Explain what this would mean for replication, and what it would mean for the organism.

Answer 1

Ligase is an enzyme needed to join DNA fragments. It is extremely important during DNA replication. This is because, it helps in joining the Okazaki fragments that are formed on lagging strand. Okazaki fragments form 3'-5' strand. It forms, lagging strand the small fragments are joined by ligase. If ligase is not present, these fragments reamin as fragments and 3'-5' strand can' t be formed.

At the beginning of each strand that is newly formed, there are primers present. The primers are removed and the new DNA strand is formed in its place.After that the ligase will join the new DNA to rest of the strand.

So, wherever joining of DNA isneeded, ligase enzyme has to be present. If it is absent in a cell DNA replication can't be completed. If the replication of the DNA can't be completed, the cells can't divide. Cell division is important for growth, repair and regeneration. In a multicellular organism, number of cells are produced regularly to replace the cells that die. So all these activities in the body will be afected in the absence of Ligase in cells.