Hi aspirant,

Biology is the branch of science that deals with living organisms and their essential  processes. It covers diverse fields, including botany, zoology, conservation, ecology, evolution, genetics, marine biology, medicine, physiology etc.

The second part of question  is not clear but there are many theories about the origin of life. It includes the start of life from simple organic molecules, replicating molecules with natural selection, Some cells began to evolve modern metabolic processes and out-competed those with older forms of metabolism etc.

Hope it helps!!