Match the following – Vitamins and respective deficiency diseases :
Vitamins
a. Vit. A
b. Vit. D
c. Vit. C
d. Vit. B12
Deficiency disease
i. Rickets
ii. Scurvy
iii. Anaemia
iv. Night blindness

Question

UnlockIAS · Accepted Answer

Correct — option (2), which pairs a. with iv., b. with i., c. with ii. and d. with iii. Before matching anything, note that the two lists are printed side by side only because the reader has to join them; the order in which they happen to sit on the page asserts nothing. Take the vitamins one at a time. Statement a., Vit. A, pairs with iv., Night blindness. Vitamin A, or retinol, is the raw material from which the rod cells of the retina build rhodopsin, the pigment that lets the eye register very dim light. When the vitamin is short the rods cannot regenerate the pigment fast enough and the first symptom is an inability to see after dusk or on moving from a lit room into a dark one; if the deficiency deepens it goes on to dry the conjunctiva and cornea, the condition called xerophthalmia, and can end in blindness. Statement b., Vit. D, pairs with i., Rickets. Vitamin D governs the absorption of calcium and phosphate from the intestine, so without it the growing skeleton cannot be properly mineralised: in children the soft bones bend under the body's weight, giving the bowed legs and deformed rib cage of rickets, while the same deficiency in an adult, whose bones have stopped growing, produces osteomalacia instead. Statement c., Vit. C, pairs with ii., Scurvy. Ascorbic acid is required to build normal collagen, the protein that gives connective tissue, blood vessel walls and gums their strength, so a deficiency shows up as bleeding and spongy gums, loose teeth, bleeding under the skin and wounds that will not heal — the classic disease of long sea voyages. Statement d., Vit. B12, pairs with iii., Anaemia. Cobalamin, the only vitamin that contains a metal atom, cobalt, is needed for the DNA synthesis that lets bone marrow turn out red blood cells; without it the marrow releases large, immature and inefficient cells and the result is a megaloblastic anaemia. Only option (2) reproduces all four of these pairings.

Why the other options are wrong — (a) Every one of the four pairings in this option is wrong, which makes it useful mainly as a check on whether the candidate can settle even one pair with confidence. It hands Vitamin A the anaemia that belongs to B12, gives Vitamin D the scurvy that belongs to C, attaches night blindness to Vitamin C, and leaves rickets with Vitamin B12. A single secure pairing is enough to strike it out: anyone who knows that Vitamin A protects night vision, or that Vitamin D and rickets go together through calcium and the growing skeleton, can eliminate this option after reading only its first or second entry, which is how matching questions should be worked.  (c) This option swaps the first two vitamins and then swaps the last two, so it is built out of the two most tempting confusions at once. It gives rickets to Vitamin A and night blindness to Vitamin D, when the direction runs the other way: the retina depends on retinol and the skeleton depends on calciferol. It then gives anaemia to Vitamin C and scurvy to Vitamin B12, reversing the other pair as well. The mnemonic anchors that break both swaps are that the name retinol carries the retina inside it, and that scurvy is the disease of sailors deprived of fresh fruit, which is a Vitamin C story and could not be a B12 story since B12 comes from animal foods rather than from citrus.  (d) This option gets none of the four right either, but it is the more dangerous of the fully wrong choices because it contains a half-truth about Vitamin C: it does not pair C with scurvy, yet it places scurvy at the top of the list against Vitamin A, close enough to catch a candidate who is scanning for the word scurvy rather than tracking which label it sits against. The disciplined method for a matching item is to write out your own four pairs before looking at any option, then find the option that reproduces your list exactly, because reading the options first invites you to search for a fragment you recognise instead of a set you have verified.

Concept: Vitamins are organic compounds the body needs in small quantities but cannot synthesise in sufficient amounts, so they have to come from the diet, and each deficiency disease is simply the failure of the particular job that vitamin performs. They divide into two groups whose behaviour differs in ways worth knowing. The fat-soluble vitamins A, D, E and K dissolve in fats, are absorbed along with dietary fat, and are stored in the liver and fatty tissue, so a deficiency takes a long time to appear and an excess can accumulate to toxic levels. The water-soluble vitamins — the B complex and vitamin C — are not stored to any great extent and any surplus is excreted, so they need regular replenishment and deficiency shows up sooner. Vitamin D is unusual in that the skin manufactures it from a cholesterol derivative under ultraviolet light, which is why sunlight rather than food is its principal source. Vitamin B12 is unusual in a different way: it contains cobalt, occurs essentially only in animal-derived foods, and needs a stomach protein called intrinsic factor to be absorbed, so a failure of that protein produces the same anaemia as a dietary shortage.

State PCS 2023 Q42 — Science & Technology PYQ with Answer

State PCS 2023 Q42 — Science & Technology PYQ with Answer