Hello aspirant,

Life Science is a broad spectrum course because it includes all the other mentioned domains. If you are confused with what to choose then go for Life Sciences. 
After BSc: After you are done with your graduation you can continue with science if you want. Do MSc then BEd (job profile: teacher) , MSc then MPhil and PhD (Job Profile: researcher or Professor) and if you don't want to continue with science and want a job then you can give competitive exams like SSC ( Staff Selection Commission) or Bank PO( Probationary Officer).