The right answer is A) Uses H2S for an energy source.
Beggiatoa is a bacterium that lives in sulphide-rich environments. They use H2S as a source of energy.
Purple sulfur bacteria, are also bacteria that depend on the presence of H2S but do not use it for the purpose of producing energy. They use it as the ultimate electron acceptor in its respiratory chain (instead of oxygen), since they are anaerobic bacteria.
The answer is mutagens. In genetics, mutagen is a physical or chemical agent that changes the genetic material usually that of DNA of an organism and thus increases the frequency of mutations above the natural background level. DNA changes caused by mutagens may harm cells and cause certain diseases such as cancer.
Answer:
B. Virus
Explanation:
Once attached to a host cell, a virus injects its nucleic acid into the cell. The nucleic acid takes over the normal operation of the host cell and the host cell produces multiple copies of the virus.