SSC CGL Human Body Questions and Answers – Page 2

Therefore option C, Skull (cranium), is factually consistent with the stem, the marked correct index, and the explanation.✅ Correct Answer: C — Skull (Cranium) The Skull (Cranium) is the bony structure that encases and protects the brain from external injuries. The cranium consists of 8 cranial bones fused together at immovable joints called sutures. The total human skull has 22 bones (8 cranial + 14 facial bones). It also protects the sense organs (eyes, ears, nose). Vertebra — Vertebrae form the spinal column (backbone) and protect the spinal cord, not the brain. Sternum — Sternum (breastbone) is the flat bone in the chest that protects the heart and lungs, not the brain. Rib — Ribs form the rib cage that protects the heart and lungs; they have no role in brain protection. 📝 Important Note: Skull has 22 bones: 8 cranial (protect brain) + 14 facial. Heart lungs are protected by 12 pairs of ribs + sternum.

Therefore option C, Epidermis, is factually consistent with the stem, the marked correct index, and the explanation.✅ Correct Answer: C — Epidermis The Epidermis is the outermost layer of the skin. Epidermis contains Keratinocytes (produce keratin for protection) and Melanocytes (produce melanin for skin color). Dermis — Dermis is the middle/second layer of skin beneath the epidermis; contains hair follicles, sweat glands, blood vessels, and nerve endings. Hypodermis — Hypodermis (Subcutaneous layer) is the deepest layer of skin; mainly consists of fat and connective tissue for insulation and energy storage. Subcutaneous layer — Same as Hypodermis, the deepest layer; not the outermost. 📝 Important Note: Skin has 3 layers: Epidermis (outermost), Dermis (middle), Hypodermis/Subcutaneous (innermost). Skin is the largest organ of the human body. Epidermis has 5 sub-layers (strata). Melanin in epidermis determines skin color and protects from UV rays.

Therefore option C, Somatic nervous system, is factually consistent with the stem, the marked correct index, and the explanation.✅ Correct Answer: C — Somatic nervous system The Somatic Nervous System (SNS) controls voluntary (conscious) movements such as walking, talking, and writing. Autonomic nervous system — Controls involuntary actions like heartbeat, digestion, and breathing; not under conscious control. Parasympathetic system — Part of the Autonomic NS; responsible for 'rest and digest' functions (slowing heart rate, stimulating digestion). Sympathetic system — Part of the Autonomic NS; responsible for 'fight or flight' response (increases heart rate, dilates pupils). 📝 Important Note: Nervous system divided into CNS (Brain + Spinal Cord) and PNS. PNS has Somatic NS (voluntary) and Autonomic NS (involuntary). Autonomic NS has Sympathetic (fight or flight) and Parasympathetic (rest and digest).

call the exact source–function or deficiency–disorder pair and eliminate neighbouring concepts. Therefore option D, Both RBC and Platelets, is factually consistent with the stem, the marked correct index, and the explanation.✅ Correct Answer: D — Both RBC and Platelets Both Red Blood Cells (RBCs/Erythrocytes) and Platelets (Thrombocytes) lack nuclei in their mature form in humans. RBCs lose their nucleus during maturation to maximize space for haemoglobin and oxygen transport. Platelets are not cells but cell fragments from megakaryocytes, and they naturally have no nucleus. White blood cells (WBCs/Leukocytes) — WBCs DO have a nucleus; they use it for immune functions like producing antibodies. Platelets alone — While platelets lack nucleus, RBCs also lack nucleus, so D (both) is correct. Red blood cells alone — While RBCs lack nucleus, platelets also lack nucleus, so D (both) is correct. 📝 Important Note: Mature human RBCs and Platelets both lack a nucleus. WBCs have a nucleus.

tomy, physiology, blood, hormones, vitamins, immunity, pathogens, or disease. Therefore option C, 5-6 litres, is factually consistent with the stem, the marked correct index, and the explanation.✅ Correct Answer: C — 5-6 litres An average adult human body contains approximately 5 to 6 litres of blood. This accounts for about 7-8% of total body weight. Blood consists of plasma (55%), red blood cells (45%), and small amounts of WBCs and platelets. Blood volume can vary based on body size, age, and gender. 2-3 litres — This is too low; 2-3 litres would indicate severe blood loss (hemorrhage). 4-5 litres — Close but not the standard value; the average is 5-6 litres for adults. 8-9 litres — This is too high; no healthy adult has 8-9 litres of blood normally. 📝 Important Note: Normal adult blood volume = 5-6 litres (men: ~5.5L, women: ~4.5L). Blood makes up ~8% of body weight. A donation of ~450 ml is safe as the body replenishes it quickly. This is a standard SSC CGL factual question about human biology.

Do not confuse an organ that produces a substance with an organ on which that substance acts, or a vector with the organism that causes a disease. Therefore option C, Protozoa, is factually consistent with the stem, the marked correct index, and the explanation.✅ Correct Answer: C — Protozoa Malaria is caused by Plasmodium, a protozoan parasite. Bacteria — Bacteria cause diseases like Tuberculosis (TB), Cholera, Typhoid; not Malaria. Virus — Viruses cause diseases like Dengue, HIV, Influenza; not Malaria. Fungus — Fungi cause diseases like Ringworm, Athlete's foot; not Malaria. 📝 Important Note: Malaria is caused by Plasmodium (Protozoa), transmitted by female Anopheles mosquito. Dengue is caused by Virus, transmitted by Aedes mosquito. Malaria is a major health concern in tropical countries including India.

Do not confuse an organ that produces a substance with an organ on which that substance acts, or a vector with the organism that causes a disease. Therefore option C, Liver, is factually consistent with the stem, the marked correct index, and the explanation.✅ Correct Answer: C — Liver Hepatitis means inflammation of the Liver. It is most commonly caused by Hepatitis viruses (A, B, C, D, E). Kidney — Kidney inflammation is called Nephritis; affected by diseases like kidney stones, UTI. Heart — Heart inflammation is called Myocarditis; it is not related to Hepatitis. Lung — Lung inflammation is called Pneumonitis or Pneumonia; Hepatitis does not affect lungs. 📝 Important Note: Hepatitis B and C can lead to chronic liver disease and liver cancer. Hepatitis A and E spread through contaminated food/water. Hepatitis B spreads through blood and body fluids. Hepatitis B vaccine is available. Liver is the largest internal organ of the human body.

Then recall the exact source–function or deficiency–disorder pair and eliminate neighbouring concepts. Therefore option C, Iodine, is factually consistent with the stem, the marked correct index, and the explanation.✅ Correct Answer: C — Iodine Goitre (Ghengha Rog) is caused by deficiency of Iodine. The thyroid gland needs iodine to produce thyroid hormones (T3 and T4). When iodine is insufficient, the thyroid gland enlarges (swells) to compensate, forming a visible swelling in the neck called Goitre. Iron — Iron deficiency causes Anaemia (low haemoglobin), not Goitre. Calcium — Calcium deficiency causes Osteoporosis (weak bones) and Tetany (muscle cramps), not Goitre. Zinc — Zinc deficiency causes slow wound healing and impaired immunity, not Goitre. 📝 Important Note: Goitre is prevented by using Iodized salt. Iodine deficiency is the most common preventable cause of intellectual disability worldwide. India added iodine to common salt to eliminate iodine deficiency disorders (IDD).

sease is caused by deficiency of Vitamin B1 (Thiamine)? Pellagra is incorrect because it refers to a different organ, substance, process, or medical association. Anaemia is also incorrect; it may be biologically important, but its principal role or defining feature is not the one being tested here. Rickets is incorrect because its function, source, target, or disease relationship does not match the question. Decide whether it concerns anatomy, physiology, blood, hormones, vitamins, immunity, pathogens, or disease. Then recall the exact source–function or deficiency–disorder pair and eliminate neighbouring concepts. Do not confuse an organ that produces a substance with an organ on which that substance acts, or a vector with the organism that causes a disease. Therefore option B, Beri-beri, is factually consistent with the stem, the marked correct index, and the explanation. Beri-beri is caused by vitamin B1 (thiamine) deficiency.

ce–function or deficiency–disorder pair and eliminate neighbouring concepts. Do not confuse an organ that produces a substance with an organ on which that substance acts, or a vector with the organism that causes a disease. Therefore option C, Scurvy, is factually consistent with the stem, the marked correct index, and the explanation.✅ Correct Answer: C — Scurvy Scurvy is caused by deficiency of Vitamin C (Ascorbic Acid). Vitamin C is essential for the synthesis of collagen protein. Historically, sailors suffered from scurvy due to lack of fresh fruits. Rickets — Caused by deficiency of Vitamin D (or calcium/phosphorus); leads to weak, soft bones in children. Pellagra — Caused by deficiency of Vitamin B3 (Niacin); characterized by 3 Ds: Dermatitis, Diarrhea, Dementia. Beri-beri — Caused by deficiency of Vitamin B1 (Thiamine); affects the nervous system and heart. 📝 Important Note: Vitamin C deficiency = Scurvy. Vitamin D deficiency = Rickets. Vitamin B1 deficiency = Beri-beri. Vitamin B3 deficiency = Pellagra. Citrus fruits are the best source of Vitamin C.