General Science Questions (MCQs) for Competitive Examinations

Notes:
In 1897, J.J. Thomson discovered the electron by experimenting with a Crookes, or cathode ray, tube. He demonstrated that cathode rays were negatively charged.

Notes:
Vitamin C is quite unstable when cooked or stored improperly. It is very liable and easily destroyed during cooking as well as storage. It is a water-soluble and temperature-sensitive vitamin, so is easily degraded during cooking, and elevated temperatures and long cooking times have been found to cause particularly severe losses of vitamin C.

Notes:
Solitary cymose inflorescence refers to a determinate inflorescence composed of a single flower. Examples include poppy, gardenia (ornamental plant), tulip, etc. Flowers are said to be solitary when the plant bears only one, or when single flowers appear on the ends of lateral branches that are remote from one another.

Notes:
Typhoid fever, also known simply as typhoid, is a bacterial infection due to Salmonella typhi, also known as Salmonella enterica serotype typhi, that grows in the intestines and blood. Typhoid is spread by eating or drinking food or water contaminated with the feces of an infected person.

Notes:
Polar bears are supremely adapted to their environment – they have a number of traits that help them to cope with snow, ice, and below-freezing temperatures. They have a layer of fat that can be four inches (10 cm) thick. Although their fur is the primary source of insulation, the fat helps keep heat in as well.

Notes:
Meibomian glands are the tiny oil glands which line the margin of the eyelids (the edges which touch when the eyelids are closed). These glands secrete oil which coats the surface of our eyes and keeps the water component of our tears away from evaporating (drying out). Together, the water and the oil layer make up the tear film.

Notes:
Acidity and alkalinity are expressed on the pH scale, which ranges from 0 (strongly acidic) to 14 (strongly basic or alkaline). A pH of 7.0, in the middle of this scale, is neutral. Blood is normally slightly basic, with a normal pH range of 7.35 to 7.45.

Notes:
Riboflavin is also known as vitamin B2. It is a vitamin found in food and used as a dietary supplement. Food sources include eggs, green vegetables, milk and other dairy product, meat, fish, mushrooms, and almonds. Riboflavin is a water soluble and heat-stable vitamin that the body uses to metabolize fats, protein, and carbohydrates into glucose for energy.

Notes:
A Barr body is the inactive X chromosome in a female somatic cell in those species in which sex is determined by the presence of the Y or W chromosome rather than the diploidy of the X or Z. A typical human female has only one Barr body per somatic cell, while a typical human male has none.

Notes:
Vitamin E is a fat soluble vitamin that is essential in many physiological processes. It plays an important role in the health and maintenance of proper reproductive system function. Without vitamin E the body cannot reproduce. It is also essential during pregnancy and is needed for the proper health and development of the fetus.