Why are Earth's materials and energy considered to be in equilibrium? (Select all that apply)

Earth's materials are recycled and reused constantly
Earth's materials are all divided in equal amounts
Energy is balanced and cannot be created or destroyed
O Energy is always converted into usable forms

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?