Question

What is the function of telomeres in eukaryote DNA? How are they synthesised? [8 marks]

Answer 1

A telomere is located at both the end of DNA. The main job of telomere is to prevent the loss of chromosomes from both ends and it also prevents the fusion of two chromosomes.

They are synthesized during replication of DNA by telomerase, a ribonucleoprotein that uses its sown RNA template to extend both end of chromosome at lagging strand. When the primer from the end at the lagging strand is removed, the end of the chromosome is extended by telomerase which uses its own RNA as a template. Once the end of the chromosome is extended DNA polymerase now uses DNA as a template and replicates the telomere. The extra nucleotide at the end are removed by exonuclease activity.