What cells do not have telomeres?
Since first discovered in Tetrahymena thermophila in 1985 (82), telomerase activity was found to be absent in most normal human somatic cells but present in over 90% of cancerous cells and in vitro-immortalized cells (124, 210).
Why is telomerase not found in bacteria prokaryotes?
It is an enzyme that contains only a short RNA molecule. Why is telomerase not found in prokaryotes? because bacteria often have circular plasmids.
Do bacteria have introns?
Bacterial gene do not possess intron, their coding sequences are not interupted. … In higher eucaryotes there are often many introns within a gene, so one needs to specify what segments of a gene are coding and what are introns. However in bacteria introns are very rare and most genes have none.
Do viruses have telomeres?
Cellular telomeres are themselves maintained by viral-like mechanisms, including self-propagation by reverse transcription, recombination, and retrotransposition. Viral TR elements, like cellular telomeres, are essential for viral genome stability and propagation.
Are telomeres single stranded?
Telomeres terminate nearly exclusively in single-stranded DNA (ssDNA) overhangs comprised of the G-rich 3′ end. This overhang varies widely in length from species to species, ranging from just a few bases to several hundred nucleotides.
What is telomerase activity?
Telomerase is the enzyme responsible for maintenance of the length of telomeres by addition of guanine-rich repetitive sequences. Telomerase activity is exhibited in gametes and stem and tumor cells. … Besides catalytic telomere elongation, independent telomerase functions can be also involved in cell cycle regulation.