Telomerase DNA polymerase is unable to replicate the tips of chromosomes, resulting in the loss of DNA at the specialized ends of chromosomes (called telomeres) with each replication cycle. At birth, human telomeres are 15- to 20-kb pairs long and are composed of tandem repeats of a six-nucleotide sequence (TTAGGG) that associate with specialized telomere-binding proteins to form a T-loop structure that protects the ends of chromosomes from being mistakenly recognized as damaged.
The five treatments should be replicated at least three times (depending on gemmule
availability) by each team. That is, three separate gemmules should be placed in three separate wells
for the control treatment and for the most concentrated treatment, and so on. The drawing below
shows the placement of three replicates for three treatments, and teams can discuss the importance of
randomization in experimental design. Once the solutions are added to the treatment wells, a single
gemmule may be placed in each well.
The population of Western countries is aging, and cancer in older
aged persons is becoming increasingly common. The management of these
neoplasms is a novel problem. Direct information on the outcome of cancer
prevention and of cytotoxic chemotherapy in older individuals is scarce,
especially for those aged 80 and over, and it is not clear whether the same
process should direct medical decisions in younger and older persons. It is
reasonable to assume that the benefits of cancer prevention and treatment
diminish and the dangers increase with age.