Ageing is simply the matter of our bodies physically getting old and it has environmental and genetic causes. As we get older we tend to develop and maintain some habits which can affect our health either positively or negatively and this represents the accumulation of changes in a person over time. Biological immortality is a term used by biologists to distinguish cells that are not subject to the Hayflick limit. There are several factors that can slow down our ageing process. How and why we age are all under the guideline of our DNA.
DNA (deoxyribonucleic acid) is a complex molecule which consists of two strands coiled together to form a double helix. Nucleotides serve …show more content…
Blackburn, Carol W. Greider and Jack W. Szostak for the discovery of how chromosomes are protected by telomeres and the enzyme telomerase. A telomere is a stretch of DNA which has repetitive sequences of bases at the ends of chromosomes. When scientists started to develop knowledge on how genes are replicated, they realised that on one of the double strands of DNA cannot be replicated at the very end of the strand and due to this every time a cell divides its chromosomes gets shorter but telomeres explain how these codes are maintained. Telomeres serve to protect genetic information and act as caps at the end of chromosomes to prevent them getting shorter every time the cells divide. They stop telomeres from attaching to each other and stop losing genes from cell division. If chromosomes had no telomeres they would get shorter to the point where the cells cannot divide which makes them senescence (when cells remain viable but loose ability to divide) or make them die. Elizabeth Blackburn and Jack Szostak conducted an experiment which involved crossing boundaries between distance species. They did this after observing the chromosomes of a unicellular ciliate organism called Tetrahymena which showed the sequence CCCCAA repeated and observing a minichromosome which would get damaged after put into yeast cells. The DNA sequence of Tetrahymena was isolated and was attached on to the minichromosomes then was put back into the yeast cells. They also put some minichromosomes that did not have the telomere DNA sequence. The results showed that the sequence of the telomere DNA had protected the minichromosomes from damage as they were not shortened. The yeast cells that had the chromosomes with no telomere sequence showed that it became damaged and shortened. After putting all observations together, Carol Greider and Blackburn came to a theory that telomeres could have been formed from an