What is telomere, and what is its role in chromosomes?

A telomere is the protective cap at the end of a chromosome that prevents the chromosome from deteriorating or fusing with neighbouring chromosomes.

Telomeres are essentially sequences of repetitive DNA at the ends of a chromosome. They are often compared to the plastic tips on shoelaces because they prevent chromosome ends from fraying and sticking to each other, which would scramble an organism's genetic information to cause cancer, other diseases or death.

Each time a cell divides, the telomeres get shorter. When they get too short, the cell can no longer divide and it becomes inactive or "senescent" or it dies. This shortening process is associated with ageing, cancer and a higher risk of death. So telomeres also have been compared with a bomb fuse.

However, in some cells, like stem cells and cancer cells, an enzyme called telomerase can maintain the length of the telomeres. This allows these cells to divide indefinitely. The discovery of telomerase and its role in maintaining the length of telomeres has been a significant breakthrough in the field of molecular biology. It has opened up new avenues for research in ageing and cancer.

In addition to their role in cell division, telomeres also play a crucial role in meiosis, the process of cell division that produces reproductive cells. During meiosis, chromosomes pair up and exchange genetic information. Telomeres help ensure that this process happens correctly, by preventing chromosomes from fusing together or rearranging, which could lead to genetic disorders.

In summary, telomeres play a vital role in preserving the genetic information in our cells, regulating cell division, and preventing genetic disorders. They are a key area of study in the fields of ageing, cancer, and genetic diseases.