Human Body Quiz: Organs, Blood & Glands

Spoilers! These are the Starter quiz’s answers. Easy, Medium, Hard and Mixed rounds show their own answers when you finish.

1. Which is the largest gland in the human body?

   • Pancreas
   • Thyroid
   • Liver
   • Pituitary

   Answer: Liver. The liver is the largest gland and the largest internal organ. The skin is the largest organ overall.

2. The smallest bone in the human body is found in the:

   • Wrist
   • Toe
   • Nose
   • Middle ear

   Answer: Middle ear. The stapes (stirrup) in the middle ear is the smallest bone. The femur (thigh bone) is the longest.

3. People with which blood group are traditionally called universal donors?

   • AB positive
   • O negative
   • A positive
   • B negative

   Answer: O negative. O negative red cells carry no A, B or Rh antigens, so they can be given in emergencies to anyone. AB positive people are universal recipients.

4. Insulin is secreted by:

   • Beta cells of the islets of Langerhans in the pancreas
   • Alpha cells of the islets of Langerhans in the pancreas
   • The adrenal cortex
   • The thyroid gland

   Answer: Beta cells of the islets of Langerhans in the pancreas. Beta cells release insulin, which lowers blood sugar. Alpha cells of the same islets release glucagon, which raises it.

5. What is the structural and functional unit of the kidney?

   • Neuron
   • Alveolus
   • Nephron
   • Villus

   Answer: Nephron. Each kidney has about a million nephrons that filter blood and form urine. Neurons belong to the nervous system, alveoli to the lungs, villi to the intestine.

6. Which part of the brain maintains balance and posture and coordinates voluntary movements?

   • Cerebrum
   • Cerebellum
   • Medulla oblongata
   • Hypothalamus

   Answer: Cerebellum. The cerebellum coordinates movement and balance. The cerebrum handles thinking and memory; the medulla controls involuntary acts like heartbeat and breathing.

7. Bile, which helps digest fats, is produced by the:

   • Gall bladder
   • Pancreas
   • Stomach
   • Liver

   Answer: Liver. Bile is made in the liver and only stored in the gall bladder. It contains no enzymes; it emulsifies fats into small droplets.

8. What is the average lifespan of a human red blood cell?

   • About 30 days
   • About 120 days
   • About 12 days
   • About 1 year

   Answer: About 120 days. RBCs are made in the red bone marrow, live about 120 days and are then broken down mainly in the spleen and liver.

9. How many chromosomes are present in a normal human body (somatic) cell?

   • 23
   • 44
   • 46
   • 48

   Answer: 46. Body cells have 46 chromosomes in 23 pairs — 22 pairs of autosomes and one pair of sex chromosomes. Gametes have 23.

10. Digestion of starch begins in the:

    • Mouth
    • Stomach
    • Small intestine
    • Large intestine

    Answer: Mouth. Salivary amylase in the mouth starts breaking starch into sugar. Protein digestion begins in the stomach with pepsin.