All Free Everyday Science MCQs with Answers

951. The function of hemoglobin is____________?

• A. Transportation of oxygen
• B. Destruction of bacteria
• C. Prevention of anemia
• D. Utilization of energy

Explanation: Hemoglobin is the iron-containing protein in red blood cells that binds oxygen in the lungs and carries it to body tissues. It also carries a portion of carbon dioxide back toward the lungs.

952. The main function of the kidney is ____________?

• A. To control blood pressure
• B. To control body temperature
• C. To remove waste product from the body
• D. To help in digestion of food

Explanation: Kidneys filter the blood and remove nitrogenous wastes, excess water, and salts to form urine. They also help regulate blood pressure and fluid balance, but waste removal is their main listed function.

953. The main constituent of hemoglobin is___________?

• A. Chlorine
• B. Iron
• C. Calcium
• D. None of these

Explanation: Iron is the key mineral in hemoglobin's heme group, where it binds oxygen reversibly. Chlorine and calcium have important body roles but are not the main constituent of hemoglobin.

954. What is the main component of bones and teeth?

• A. Calcium carbonate
• B. Calcium phosphate
• C. Calcium sulphate
• D. Calcium nitrate

Explanation: The hard mineral portion of bones and teeth is mainly hydroxyapatite, a calcium phosphate compound. Calcium carbonate and the other listed salts are not the principal structural mineral.

955. Tibia is a bone found in the ____________?

• A. Skull
• B. Arm
• C. Leg
• D. Face

Explanation: The tibia is the shinbone, located in the lower leg between the knee and ankle. It is the larger, weight-bearing bone of the lower leg, alongside the fibula.

956. The largest part of the human brain is ___________?

• A. Medulla oblongata
• B. Cerebellum
• C. Cerebrum
• D. None of these

Explanation: The cerebrum is the largest brain region and is responsible for conscious thought, memory, sensation, and voluntary movement. The cerebellum mainly coordinates movement, while the medulla controls vital involuntary functions.

957. How many bones are there in an adult human being?

• A. 210
• B. 260
• C. 206
• D. 300

Explanation: The standard adult human skeleton contains 206 bones. The higher counts in the other options reflect neither the accepted adult total nor a normal anatomical variation.

958. Red blood corpuscles are formed in the____________?

• A. Liver
• B. Bone marrow
• C. Kidneys
• D. Heart

Explanation: In adults, red blood cells are produced mainly in the red bone marrow through erythropoiesis. The kidneys release erythropoietin, a hormone that stimulates this production, but they do not form the cells themselves.

959. Total volume of blood in a normal adult human being is

• A. 5-6 liters
• B. 3-4 liters
• C. 8-10 liters
• D. 10-12 liters

Explanation: An average adult has roughly 5 to 6 litres of blood, equal to about 7 to 8 percent of body weight. The exact volume varies with body size, sex, and health.

960. Which of the following helps in clotting of blood?

• A. Vitamin B1
• B. Vitamin B2
• C. Vitamin D
• D. Vitamin K

Explanation: Vitamin K is required for the liver to produce several clotting factors, so deficiency can lead to prolonged bleeding. Vitamins B1, B2, and D do not have this primary clotting role.