Free Human Body and Health MCQs with Answers

251. If the green leaves are placed under red light, their color will become________?

• A. Green
• B. Black
• C. Red
• D. Blue

Explanation: A green leaf reflects green light but absorbs much of the red light available to it. Under red light alone, it reflects very little, so it appears black or very dark.

252. Calcaneus bone in which part of human body?

• A. Heel
• B. Hand
• C. Arm
• D. Skull

Explanation: The calcaneus is the largest tarsal bone and forms the heel of the foot. It bears much of the body’s weight during standing and walking.

253. Tarsal bone is in the?

• A. Hand
• B. Arm
• C. Leg
• D. Foot

Explanation: Tarsal bones form the ankle and rear part of the foot. The hand contains the corresponding carpal bones.

254. Skin has ___________ layers?

• A. One
• B. Two
• C. Three
• D. Four

Explanation: In basic anatomy, the skin is described as having three layers: epidermis, dermis and the underlying subcutaneous layer. Strictly, the subcutaneous layer is beneath the skin, but it is commonly included in school-level classifications.

255. The red blood cells originate in the ____________?

• A. Brain
• B. Muscles
• C. Ligaments
• D. Bone Marrow

Explanation: Red blood cells are produced mainly in the red bone marrow, where blood-forming stem cells develop into mature erythrocytes.

256. DNA is _____________?

• A. Acetic Acid
• B. A class of nucleic acids
• C. Citric Acid
• D. None of these

Explanation: DNA, or deoxyribonucleic acid, belongs to the class of nucleic acids and stores hereditary information. It is not an acid such as acetic or citric acid.

257. Who discovered the blood group of man?

• A. Edward Jenner
• B. Laren
• C. Karl Landsteiner
• D. William Harvey

Explanation: Karl Landsteiner discovered the ABO blood-group system in 1900. Edward Jenner is associated with the smallpox vaccine, while William Harvey described blood circulation.

258. All of the following foods lack vitamin C, except

• A. Cheese
• B. Milk
• C. Rice
• D. None of these

Explanation: Milk contains a small amount of vitamin C, whereas ordinary cheese and polished rice provide little or none. Thus milk is the exception among the listed foods.

259. Which chamber of human heart pumps fully oxygenated blood to aorta and hence to the body:

• A. Right Auricle
• B. Left Auricle
• C. Right Ventricle
• D. Left Ventricle

Explanation: The left ventricle receives oxygenated blood from the left atrium and forcefully pumps it through the aorta to the body. The right ventricle sends deoxygenated blood to the lungs.

260. In bacteria mesosomes take the place of which one of the following?

• A. Ribosome
• B. Mitochondria
• C. Golgi bodies
• D. None of these

Explanation: Mesosomes were traditionally described as membrane infoldings in bacteria that perform some functions compared with mitochondria, such as supporting respiration. Modern biology generally regards them as artifacts of chemical fixation.