1. Hypertonic:- When two solution have different solute concentration.The solution which have higher concentration is called hypertonic.
2. Hypotonic:- In two solutions which have lower solute concentration is called hypotonic.
3. Homeothermic :- Animals who have constant body temperature are called homeothermic or warmblooded animals.
4. Histology:- Study of tissue organisation and their internal structure with the help of microscope .

5. Hygiene:- Science taking care of health.
6. Hydroponics:- Study of growing plants without soil in water which contain nutrient.

7. Haematology:- Study of blood.

8. Hepatology:- Study of liver.

9. Ichthyology:- Study of fishes.

10. Immunology :- Study of immune system or resistance of body to disease .