How Well Do You Know Your Own Body?: questions and answers
Study every question with its correct answer and explanation.
1. What is the largest organ of the human body?
- A. Liver
- B. Skin
- C. Brain
- D. Lungs
Answer: Skin
The skin is the body's largest organ overall, while the liver is the largest organ inside the body.
2. How many bones does a typical adult human have?
- A. 196
- B. 201
- C. 206
- D. 212
Answer: 206
Babies are born with around 270–300 bones, but many fuse together as they grow, leaving 206 in adults.
3. What is the smallest bone in the human body?
- A. Stapes (in the ear)
- B. Patella (kneecap)
- C. Coccyx (tailbone)
- D. Hyoid (in the throat)
Answer: Stapes (in the ear)
The stapes, or stirrup bone, in the middle ear is only about 3 mm long and helps carry sound vibrations to the inner ear.
4. Which is the longest bone in the human body?
- A. Humerus (upper arm)
- B. Tibia (shin)
- C. Radius (forearm)
- D. Femur (thigh)
Answer: Femur (thigh)
The femur, or thigh bone, is the longest and strongest bone in the body, making up roughly a quarter of a person's height.
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5. Which blood cells carry oxygen around the body?
- A. White blood cells
- B. Platelets
- C. Red blood cells
- D. Plasma cells
Answer: Red blood cells
Red blood cells are packed with haemoglobin, an iron-rich protein that picks up oxygen in the lungs and releases it in the tissues.
6. Which organ produces insulin?
- A. Liver
- B. Pancreas
- C. Kidney
- D. Gallbladder
Answer: Pancreas
Clusters of cells in the pancreas called the islets of Langerhans release insulin to control blood sugar.
7. How many chambers does the human heart have?
- A. 2
- B. 3
- C. 4
- D. 5
Answer: 4
The heart has two upper chambers (atria) and two lower chambers (ventricles), which keep oxygen-rich and oxygen-poor blood apart.
8. Which blood group is known as the 'universal donor' for red blood cells?
- A. A positive
- B. AB positive
- C. B negative
- D. O negative
Answer: O negative
O-negative red cells carry no A, B or RhD antigens, so they can be given to almost anyone in an emergency; AB-positive people are 'universal recipients'.
9. What is the hardest substance in the human body?
- A. Tooth enamel
- B. Bone
- C. Fingernail
- D. Cartilage
Answer: Tooth enamel
Tooth enamel is the hardest substance in the body, but it contains no living cells, so it cannot repair itself once damaged.
10. What is the normal resting heart rate range for most adults?
- A. 30–50 beats per minute
- B. 60–100 beats per minute
- C. 110–140 beats per minute
- D. 150–180 beats per minute
Answer: 60–100 beats per minute
A normal resting heart rate for adults is 60–100 beats per minute; well-trained athletes often have rates below 60.