Give two functions of plasmids in bacteria

Plasmids carry antibiotic resistant genes and spread them in the whole human or animal body.   They also carry the genes which are concerned with increasing the pathogenicity of bacteria which cause diseases (such as anthrax and tetanus).

"Plasmids have many different functions. They may contain genes that enhance the survival of an organism, either by killing other organisms or by defending the host cell by producing toxins. Some plasmids facilitate the process of replication in bacteria."

protein synthesis is an example of feedback mechanism which in homeostasis

in 1859, charles darwin set out his theory of evolution by natural selection as an explanation for adaptation and speciation. he defined natural selection as the "principle by which each slight variation [of a trait], if useful, is preserved".