In the 19th century, dmitri mendeleev predicted the existent of a then unknown element, x, with a mass of 68. he also predicted that an oxide of x would have the formula x2o3, on the modern period table. what is the group number and period of the element?

In 1994, telomerase activity was discovered in human cancer cell lines. although telomerase activity is rarely present in human somatic tissue, this discovery indicated that humans do contain the genes for telomerase proteins and telomerase rna. since inappropriate activation of telomerase may contribute to cancer, why do you think the genes coding for this enzyme have been maintained in the human genome throughout evolution?