The squid and cuttlefish have internal structural supports, while the octopus does not. What are these parts called, and how does it help these organisms?

Adistinctive characteristic of mammals that is not observed in other vertebrates is

Add solid urea to a beaker of water. the beaker gets very cold. is δh favorable or

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?