Free Human Body and Health MCQs with Answers

511. What is the average weight of Human Heart?

• A. 300 gram
• B. 350 gram
• C. 400 gram
• D. 450 gram

Explanation: An adult human heart weighs approximately 300 grams on average, although normal weight varies with body size and sex. The larger figures listed are generally above the usual average.

512. If you have "caries" then which doctor you have consult?

• A. Dermatologist
• B. Orthopaedist
• C. Dentist
• D. Nurologist

Explanation: Caries means tooth decay, caused by acids produced by bacteria in dental plaque, so it is treated by a dentist. A dermatologist treats skin disorders, not decayed teeth.

513. Humans can hear in the range of ______ to _______Hertz (Hz).?

• A. 10 Hz to 10,000 Hz.
• B. 20 Hz to 20,000 Hz.
• C. 30 Hz to 30,000 Hz.
• D. 40 Hz to 40,000 Hz.

Explanation: Normal human hearing is conventionally given as about 20 Hz to 20,000 Hz, though the upper limit often decreases with age. Frequencies below 20 Hz are infrasonic and those above 20,000 Hz are ultrasonic for humans.

514. Adult human brain is about_________% of the total body weight.

• A. 2%
• B. 3%
• C. 7%
• D. 8%Biological Sciences

Explanation: The adult brain weighs roughly 1.3 to 1.4 kg, which is about 2% of average adult body weight. It consumes a much larger share of the body's energy, so its energy use should not be confused with its mass percentage.

515. In Fishes excretory Product is__________?

• A. Nitrogen
• B. Ammonia
• C. Uria
• D. Carbon dioxide

Explanation: Most fishes are ammonotelic, meaning they excrete toxic ammonia, mainly through the gills and in dilute urine. Nitrogen is an element in ammonia, not the specific excretory product asked for.

516. What is the weight of the average human brain?

• A. 1.2 to 1.4 Kg
• B. 1.4 to 1.8 Kg
• C. 2.1 to 2.8 Kg
• D. 3.1 to 3.4 Kg

Explanation: An average adult human brain weighs about 1.3 to 1.4 kg, although its mass varies with age, sex and body size. The other ranges are considerably above the normal adult value.

517. Which of the following disease is spread by Fleas?

• A. Small pox
• B. Tetnus
• C. Typhus
• D. Yellow fever

Explanation: Fleas can transmit murine, or flea-borne, typhus through infected flea faeces. Smallpox and yellow fever spread by other routes, while tetanus is caused by bacterial contamination of wounds rather than flea transmission.

518. A dolphin perceives its environment by the sense of__________?

• A. Sight
• B. Sound
• C. Both of these
• D. None of these

Explanation: Dolphins use vision to observe nearby surroundings and sound-based echolocation to detect objects, distance and movement, especially underwater. Therefore both sight and sound are involved.

519. White bloods cells are also known as________?

• A. Thrombocytes
• B. Leucocytes
• C. Erythrocytes
• D. None of These

Explanation: White blood cells are leucocytes, which help defend the body against infections. Thrombocytes are platelets, while erythrocytes are red blood cells.

520. Human beings use _______ liters of pure oxygen per day.

• A. 550
• B. 2500
• C. 1,050
• D. 10,000

Explanation: An average person consumes roughly 550 litres of oxygen per day at rest under commonly used textbook estimates. This is oxygen actually used by metabolism, not the much larger volume of air inhaled.