General Science Questions (MCQs) for Competitive Examinations

Notes:
Blue whales are the largest animals ever known to have lived on Earth. These magnificent marine mammals rule the oceans at up to 100 feet (30 meters) long and upwards of 200 tons (181 metric tons). Their tongues alone can weigh as much as an elephant. Their hearts, as much as an automobile. Blue whales reach these mind-boggling dimensions on a diet composed nearly exclusively of tiny shrimplike animals called krill. During certain times of the year, a single adult blue whale consumes about 4 tons (3.6 metric tons) of krill a day.

Notes:
Wisdom teeth are vestigial third molars that human ancestors used to help in grinding down plant tissue. Their presence indicate the origin of human from one time ruminants.

Notes:
Small intestine is the longest part of the alimentary canal because it is the main organ of absorption and digestion of food. The surface area of the small intestine gets increased because of the presence of villi which gives food plenty of time to break down properly.

Notes:
Certain plants which possess the C4 dicarboxylic acid pathway of CO2 fixations show a structural dimorphism of chloroplast structure. Sugarcane is a common example of C4 plant that has dimorphic chloroplast. The mesophyll cells possess chloroplasts with well developed grana whereas the bundle sheath chloroplasts lack the organization of grana (Agranal chloroplasts). The malic acid is transported to the bundle sheath chloroplast (Transportations). Here it is converted to pyruvic acid and CO 2 by NADP+ malic enzyme (Decarboxylation). The pyruvic acid is then transported to mesophyll chloroplasts (Transportation).

Notes:
Edward Jenner of Britain discovered vaccination in 1796. Louis Pasteur of France discovered Rabies vaccine in 1860. Robert Koch of Germany discovered Cholera and TB germs in 1877. Sir Ronald Ross was a British Physician and entomologist, noted for identifying the links between mosquitoes and malaria. He was born in India in 1857 at Almora.

Notes:
Chlorophyll was first isolated and named by Joseph Bienaimé Caventou and Pierre Joseph Pelletier in 1817. It is a chemical found in the chloroplasts of plants that allows the plant to absorb light. Energy from the light is used in photosynthesis to make glucose.

Notes:
Tachycardia is a heart rate that exceeds the normal resting rate. In general, a resting heart rate over 80 beats per minute is accepted as tachycardia in adults. A healthy adult heart normally beats 60 to 100 times a minute when a person is at rest. Tachycardia occurs when an abnormality in the heart produces rapid electrical signals.

Notes:
Rhizobia are soil bacteria that fix nitrogen after becoming established inside root nodules of legumes. They are the only nitrogen-fixing bacteria living in a symbiotic relationship with legumes. Common crop and forage legumes are peas, beans, clover, and soy.

Notes:
Femur (thighbone) the longest bone in human body. Its average length is 19.9 inch. The femur is the only bone in the thigh. Tibia (shin bone) and Fibula (lower leg) come next in sequence with length of 16.9 and 15.9 inch respectively.

Notes:
Common table salt plays a primary role in the processes of digestion and absorption. Salt activates an enzyme in the mouth called salivary amylase. Salt also creates hydrochloric acid. Hydrochloric acid is a very important digestive secretion, which lines the stomach walls.