All are true about telomers and telomerase except:(LQ)
|A||Telomers are short repeating sequences of DNA present at linear end of chromosomes|
|B||Telomers shortening signals cell cycle arrest|
|C||Telomerase is a reverse transcriptase which is responsible for maintain the length of telomers|
|D||In cancer cells telomerase activity is lost.|
a. In tumor cells telomerase activity is reactivated.
b. Telomerase enzyme is absent from most somatic cells, and hence they suffer progressive loss of telomeres.
c. Introduction of telomerase into normal human cells causes considerable extension of their life span.
d. Telomerase activity has been detected in more than 90% of human tumors and hence telomerase activity and maintenance of telomere length are essential for the maintenance of replicative potential in cancer cells.