What is common descent? why is it important to the theory of evolution?

How is the male reproductive system different from other body systems? it isn’t necessary to vital signs. it monitors other body systems, and adjusts if necessary. it transports items from one system to another. it is the only system that produces hormones in the male.

What is the answer for the complicated molecules that make up living things usually contain carbon. why is carbon so important in these molecules?

Brian made this table to organize his notes on changes of state change of state energy change melting gain freezing lose deposition gain condensation lose