HUMAN BODY — BIOLOGY (SSC CGL Special) ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
CORE CONCEPT ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
The human body is a system of organs that work together to keep us alive. For SSC CGL, you need to know the key organs, their functions, blood composition, vitamins, hormones, and deficiency diseases. These topics appear in nearly every paper — sometimes 2 to 3 questions at once. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
KEY SYSTEMS AND RULES ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1. BLOOD AND CIRCULATORY SYSTEM - Blood has 4 components: Red Blood Cells (RBC), White Blood Cells (WBC), Platelets, Plasma.
- RBC carries oxygen using a protein called Haemoglobin. Haemoglobin contains IRON. - WBC fights infection. It is called the 'Soldier of the body.'
- Platelets help in blood clotting. - Normal blood pH = 7.35 to 7.45 (slightly alkaline).
- Normal RBC count: 4.5 to 5.5 million per cubic mm. - Human heart beats approx. 72 times per minute at rest.
- Trick to remember: RBC = Red = Iron = Oxygen. WBC = White = Warrior. 2. VITAMINS —
Vitamin A — Night blindness (deficiency). Source: Carrots, milk.
Vitamin B1 — Beriberi. Source: Rice husk.
Vitamin B2 — Ariboflavinosis (cracked lips). Source: Eggs.
Vitamin B12 — Pernicious Anaemia. Contains COBALT.
Vitamin C — Scurvy. Source: Citrus fruits. Only vitamin that is an antioxidant acid (Ascorbic Acid).
Vitamin D — Rickets (in children), Osteomalacia (in adults). Made by skin using SUNLIGHT.
Vitamin E — Infertility.
Vitamin K — Blood clotting failure. Made by intestinal bacteria.
1 — Vitamin Type: Fat-Soluble = A, D, E, K → Remember: 'ADEK' (A Dog Eats Kibble) Water-Soluble = B complex, C SHORTCUT TRICK 2 — Deficiency Disease Memory Chain: 'A Night, B Beri, C Scurvy, D Rickets, K Klot' (K = Klotting/Clotting)
HORMONES AND GLANDS - Pituitary Gland = Master Gland of the body (controls all other glands). - Thyroid Gland = Controls body metabolism. Deficiency of Iodine causes Goitre. - Pancreas = Produces Insulin (controls blood sugar). Lack of Insulin = Diabetes Mellitus. - Adrenal Gland = 'Fight or Flight' hormone = Adrenaline. - Ovaries/Testes = Reproductive hormones (Estrogen/Testosterone). SHORTCUT TRICK 3 — Pancreas = INSULIn = Sugar control. Think: 'INSULIn INSULates Sugar.'
IMPORTANT ORGANS - Largest organ = Skin. - Largest internal organ = Liver (also the heaviest). - Smallest bone = Stapes (in ear). - Largest bone = Femur (thigh bone). - Kidney filters blood and removes urea. Basic unit = Nephron. - Brain has 3 main parts: Cerebrum (thinking), Cerebellum (balance), Medulla Oblongata (breathing, heartbeat). ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
— WHAT GETS ASKED ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ SSC CGL most frequently asks: - Vitamin deficiency diseases (appears in almost every paper) - Name of hormones and their glands - Largest/smallest/heaviest organ or bone - Function of specific organs - Blood groups and Rh factor ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Recall trick — 'C Scurvy.'
Vitamin C = Ascorbic Acid.
Scurvy = bleeding gums, weak immunity. Answer: Vitamin C. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ WORKED EXAMPLE 2 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Q: Which gland is called the Master Gland?
Remember — Master controls others.
Pituitary Gland controls all endocrine glands.
It is located at the base of the brain. Answer: Pituitary Gland. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
— NUMBER 1 TRAP ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Students confuse Liver and Skin as the largest organ. SKIN is the LARGEST organ of the body. LIVER is the largest INTERNAL organ.
SSC CGL deliberately uses this to trap students. Always check if the question says 'internal' or not.
31graded MCQs · easy to hard · full solution & trap analysis · showing 20 of 31
Difficulty-graded, bookmarkable, with timed mode. Free account — no credit card.