Living organisms that are able to make their own food are
producers
primary consumers
secondary consumers
decomposers

Producers are the living organisms that can make their own food

Living organisms that are able to make their own food are producers.

The higher you go up the less oxygen there is 

When a virus infects a host cell, it uses the cell's machinery to make copies of its own genetic material in a process called replication. finally, during the process of self-assembly, that protein shell and the copies of the virus's genetic material are assembled into new viruses.