All Free Everyday Science MCQs with Answers

991. Urine is produced in __________?

• A. Kidneys
• B. Lungs
• C. Large intestine
• D. Liver

Explanation: The kidneys filter blood and process the filtrate into urine through microscopic units called nephrons. The lungs remove carbon dioxide and water vapour, but they do not produce urine.

992. The fluid part of blood is known as __________?

• A. plasma
• B. platelets
• C. blood cells
• D. None of these

Explanation: Plasma is the pale liquid portion of blood in which blood cells and platelets are suspended. It also transports nutrients, hormones, wastes and proteins throughout the body.

993. Each day human body breathe in __________ liters of air.

• A. 5,000 to 10,000
• B. 10,000 to 15,000
• C. 15,000 to 20,000
• D. 20,000 to 25,000Exploring Online Chemistry Courses

Explanation: An average adult moves roughly 10,000 to 15,000 litres of air through the lungs per day at ordinary activity levels. The exact amount changes with breathing rate, body size and exercise.

994. Deficiency of Vitamin-D results in __________?

• A. night blindness
• B. rickets
• C. scurvy
• D. hair fall

Explanation: Vitamin D is needed for proper absorption and use of calcium and phosphate in bone formation. Its deficiency causes rickets in children, producing weak and deformed bones; night blindness results from vitamin A deficiency.

995. The average adult has a blood volume of about __________ liters.

• A. 4
• B. 5
• C. 6
• D. 7

Explanation: A typical adult breathes about 5 to 8 litres of air per minute at rest, which totals roughly 7,000 to 12,000 litres per day. Therefore, 5 litres is the closest standard estimate among the options.

996. The lifespan of Red Blood Cells is __________ days?

• A. 60
• B. 120
• C. 180
• D. 240Chemistry

Explanation: Red blood cells survive for about 120 days before old cells are removed mainly by the spleen and liver. Their limited lifespan is related to the absence of a nucleus and other cell organelles.

997. Deficiency of Vitamin-A results in __________?

• A. Night blindness
• B. rickets
• C. scurvy
• D. hair fall

Explanation: Vitamin A is needed for the visual pigment rhodopsin, so its deficiency commonly causes night blindness. Rickets results from vitamin D deficiency, while scurvy results from vitamin C deficiency.

998. Long-sight defect could be corrected by using __________ lens?

• A. concave
• B. Convex
• C. diverging
• D. none of these

Explanation: Long-sightedness, or hypermetropia, occurs when near images would focus behind the retina; a convex lens brings the focus forward onto the retina. A concave or diverging lens is used for short-sightedness.

999. Severe deficiency of Vitamin D results in __________.

• A. scurvy
• B. rickets
• C. night blindness
• D. None of these

Explanation: Severe vitamin D deficiency causes rickets in children because poor calcium absorption weakens and deforms growing bones. Scurvy is caused by vitamin C deficiency, not vitamin D deficiency.

1000. Which of following is the disease of eyes.?

• A. Trachoma
• B. Glaucoma
• C. Cataract
• D. All of these

Explanation: Trachoma is an infectious eye disease, glaucoma damages the optic nerve through commonly increased eye pressure, and cataract clouds the lens. Therefore all three listed conditions affect the eyes.