The author, Mr Santosh Kumar Srivastava received his Master degree from Agra University in 1972. As a distinguished and well known Biology Teacher, he spent considerable time (1985-2008) at G.I.C. Raebareli (UP), where he was honored as "Medicomaker" by the citizens, on the basis of record medical selections, he is credited for. He has always been interested in impressive teaching and his emphasis was on the fundamentals of biology.  Many of his past students along with his two sons are enjoying medical profession. He has been retired from GIC Hussainabad, Lucknow (UP) in 2010. He is paying attention in transferring mastered knowledge to next generations. The book in your hand is the outcome of his 40 years of teaching experience and many years of writing enjoyment.