What holds dna and controles cells activities

Disinfection of impression materials is usually accomplished by a. sterilization with high heat. b. spray or immersion in a chemical disinfectant. c. sterilization with steam under pressure. d. allowing the impression to sit 24 hours in water until all the organisms die.

What is the importantence of the carbon and nitretan cycles in the environment

When analyzing tree rings, what do scientists assume a thin ring indicates?