Questions

A protein that acts as a hormone is INSULIN.

Insulin is a peptide hormone produced by beta cells of the pancreatic islets; it is considered to be the main anabolic hormone of the body.  Insulin helps keeps your blood sugar level from getting too high or too low.  

the gaseous form of water is called water vaour.

Ammonia is a base. One adding ammonia to water,the resulting solution will become basic. pH of an alkaline solution is 7. So the pH will increase

An operating system is a program that acts as an intermediary between the user and the computer hardware. The purpose of an OS is to provide a convenient environment in which user can execute programs in a convenient and efficient manner. It is a resource allocator responsible for allocating system resources and a control program which controls the operation of the computer hardware.

Plants grow in size both in height and in girth. Enlargement of cells already present cannnot contribute much to the growth. Only addition of more and more cells could increase the size of the plant considerably.