| Nutrients | Chemical substances taken as food which are necessary for various function, growth and health of living |
| Nanotechnology | The study 'Science of small7 is known as nanotechnology |
| Neurology | Study of nervous system |
| Neonatology | Study of new bom |
| Nephrology | Study of kidneys |
| Osmosis | Movement of water molecule across semipermeable membrane from the region of its higher concentration to the region of lower concentration |
| Odontology | Study of teeth and gum |
| Osteology | Study of bones |
| Oncology | Study of cancer and tumours |
| Obstetrics | Science related with care of pregnant women before, during and after child birth |
| Ornithology | Study of birds |
| Ophthalmology | Study of eyes |
| Orthopaedics | Diagnosis and repair of disorder of locomotery system |
| Phytoplankton | Microscopic organism which passively float on the surface of water |
| Parasite | Organism which depend on other living organism for their food and shelter |
| Poikilothermic | Organism which change their body temperature according to surrounding. These are also called cold blooded animal |
| Pigment | A substance which absorb light of certain wavelength like chlorophyll found in green leaves |
| Paleontology | Study of fossils |
| Physiology | Study of function of various system of organism |
| Pathology | Study of diseases, effects, causable agents and transmission of pathogens |
| Pomology | Study of fruit and fruit yielding plant |
| Psychiatry | Treatment of mental disorders |
| Psychology | Study of human mind and behaviour |
| Pisciculture | Rearing of fishes |
| Phycology | Study of algae |
| Paediatrics | Branch of medicine dealing with children |
| Parasitology | Study of parasites |
| Pharmacology | The science which deal with drugs |
| Photobiology | Effect of light on various biological processes |
| Phylogeny | Evolutionary history of organism |
| Physiotherapy | Treatment of body defects through massage and exercise |
| Radiology | Science dealing with the effect of radiation on living beings |
| Rhinology | Study of nose and olfactory organs |
| Sonography | Study of ultrasound imaging |
| Saurology | Study of lizards |
| Serology | Study of serum, interaction of antigen and antibodies in the blood |
| Sphygmology | Study of pulse and arterial pressure |
| Taxonomy | Study of classification, nomenclature and identification of organism |
| Telepathy | Communication of thoughts or ideas from one mind to another without normal use of senses. In other word this is the process of mental contact |
| Veterinary Science | Science of health care and treatment of domestic animals |