401. A prolonged deficiency of vitamin A is most directly associated with:
ⓐ. scurvy and delayed wound healing
ⓑ. beriberi and impaired carbohydrate metabolism
ⓒ. night blindness and possible xerophthalmia
ⓓ. rickets and defective bone mineralisation
Correct Answer: night blindness and possible xerophthalmia
Explanation: Vitamin A is required for normal visual function, particularly adaptation to dim light. Inadequate supply may first produce difficulty seeing under low-light conditions, known as night blindness. More severe or prolonged deficiency can damage epithelial tissues of the eye and contribute to xerophthalmia. Scurvy results from vitamin C deficiency, while beriberi is linked with vitamin \(\mathrm{B_1}\) deficiency. Rickets develops from inadequate vitamin D activity during childhood.
402. A child can see normally in bright daylight but has increasing difficulty seeing after entering a dimly lit room. The most likely nutritional deficiency is:
ⓐ. vitamin A deficiency
ⓑ. vitamin K deficiency
ⓒ. vitamin \(\mathrm{B_{12}}\) deficiency
ⓓ. vitamin E deficiency
Correct Answer: vitamin A deficiency
Explanation: Adaptation to dim light depends on vitamin-A-related visual chemistry in the retina. A deficiency may impair this process before severe daytime visual loss occurs. The described symptom is therefore characteristic of night blindness. Vitamin K deficiency mainly affects blood coagulation, while vitamin \(\mathrm{B_{12}}\) deficiency is associated with abnormal red-blood-cell formation. Vitamin E functions mainly as an antioxidant and does not produce this classic early visual symptom.
403. Beriberi is most closely associated with deficiency of:
ⓐ. ascorbic acid
ⓑ. thiamine
ⓒ. calciferol
ⓓ. phylloquinone
Correct Answer: thiamine
Explanation: Vitamin \(\mathrm{B_1}\), or thiamine, participates in coenzyme systems involved in carbohydrate metabolism. Deficiency disrupts energy metabolism, especially in tissues with substantial energy demands. Beriberi may involve neurological, muscular or cardiovascular disturbances depending on the form and severity. Vitamin C deficiency causes scurvy, and vitamin D deficiency impairs bone mineralisation. Vitamin K deficiency is recognised mainly through defective clotting.
404. A patient has megaloblastic anaemia caused by inadequate availability of a cobalt-containing vitamin. The deficient vitamin is:
ⓐ. retinol
ⓑ. ascorbic acid
ⓒ. calciferol
ⓓ. cobalamin
Correct Answer: cobalamin
Explanation: Vitamin \(\mathrm{B_{12}}\), or cobalamin, contains cobalt within its molecular structure. Adequate availability is necessary for normal red-blood-cell development and other metabolic functions. Deficiency can produce megaloblastic anaemia because cell division and maturation are disturbed. Pernicious anaemia is a particular condition in which vitamin \(\mathrm{B_{12}}\) absorption is impaired, often because intrinsic-factor-related uptake is defective. The presence of cobalt and the blood-cell abnormality together identify vitamin \(\mathrm{B_{12}}\).
405. Swollen or bleeding gums, poor wound healing and weakening of connective tissue most strongly suggest deficiency of:
ⓐ. vitamin K
ⓑ. vitamin D
ⓒ. vitamin C
ⓓ. vitamin A
Correct Answer: vitamin C
Explanation: Vitamin C is required for processes supporting normal collagen formation. Collagen contributes to connective-tissue strength, wound healing and the integrity of blood-vessel walls. Deficiency therefore produces symptoms such as bleeding gums, easy bruising and delayed healing. The resulting disease is called scurvy. Vitamin K deficiency can also increase bleeding, but it does so mainly through impaired coagulation rather than defective connective-tissue support.
406. The correct relationship between vitamin D deficiency and bone disease is:
ⓐ. rickets in children and osteomalacia in adults
ⓑ. osteomalacia in children and rickets in adults
ⓒ. scurvy in children and beriberi in adults
ⓓ. night blindness in children and xerophthalmia in adults
Correct Answer: rickets in children and osteomalacia in adults
Explanation: Vitamin D supports calcium and phosphate balance needed for proper bone mineralisation. In growing children, deficiency interferes with mineralisation of developing bones and produces rickets. In adults, the corresponding defect in already formed bone is called osteomalacia. The age distinction reflects differences between a growing skeleton and a mature skeleton. Scurvy, beriberi and night blindness belong to deficiencies of other vitamins.
407. A patient shows prolonged bleeding after a minor injury despite having an adequate platelet count. A nutritional deficiency affecting clotting-protein function is suspected. The most relevant vitamin is:
ⓐ. vitamin E
ⓑ. vitamin K
ⓒ. vitamin A
ⓓ. vitamin \(\mathrm{B_1}\)
Correct Answer: vitamin K
Explanation: Vitamin K is required for the normal formation or activation of several proteins involved in blood coagulation. Deficiency can therefore prolong bleeding even when platelet number is not the primary problem. The vitamin does not act as a physical clot by itself; it supports the biochemical machinery that produces effective coagulation. Vitamin E mainly protects lipid-rich structures from oxidation. Vitamins A and \(\mathrm{B_1}\) are linked more closely with vision and carbohydrate metabolism, respectively.
408. Match each deficiency condition in Column I with the responsible vitamin in Column II.
| Column I | Column II |
|---|
| P. Scurvy | 1. Vitamin D |
| Q. Beriberi | 2. Vitamin C |
| R. Night blindness | 3. Vitamin \(\mathrm{B_1}\) |
| S. Rickets | 4. Vitamin A |
ⓐ. P-3, Q-2, R-1, S-4
ⓑ. P-4, Q-1, R-3, S-2
ⓒ. P-1, Q-4, R-2, S-3
ⓓ. P-2, Q-3, R-4, S-1
Correct Answer: P-2, Q-3, R-4, S-1
Explanation: Scurvy results from vitamin C deficiency, so P matches 2. Beriberi is caused by inadequate vitamin \(\mathrm{B_1}\), linking Q with 3. Night blindness is a classic early manifestation of vitamin A deficiency, so R matches 4. Rickets in children results from inadequate vitamin D activity, linking S with 1. Each disease reflects failure of a different biochemical or physiological function.
409. Consider the following statements.
Statement I: Vitamin C deficiency may impair collagen-related tissue maintenance.
Statement II: Vitamin K deficiency may impair normal blood coagulation.
Statement III: Vitamin A deficiency is the principal cause of beriberi.
The acceptable statements are:
ⓐ. I only
ⓑ. I and II only
ⓒ. II and III only
ⓓ. I, II and III
Correct Answer: I and II only
Explanation: Vitamin C supports connective-tissue integrity and wound healing through collagen-related biochemical processes, so Statement I is acceptable. Vitamin K is required for normal clotting-protein function, making Statement II acceptable. Beriberi is caused by vitamin \(\mathrm{B_1}\) deficiency rather than vitamin A deficiency. Vitamin A deficiency instead affects vision and epithelial tissues. Statement III therefore confuses two unrelated deficiency patterns.
410. A person with severe long-term fat malabsorption develops poor night vision, defective bone mineralisation and abnormal bleeding. The combined symptoms are best explained by reduced absorption of:
ⓐ. vitamins \(\mathrm{B_1}\), \(\mathrm{B_{12}}\) and C
ⓑ. vitamins B complex and C only
ⓒ. vitamins A, D and K
ⓓ. vitamin C alone
Correct Answer: vitamins A, D and K
Explanation: Vitamins A, D and K are all fat-soluble and depend substantially on normal lipid absorption. Vitamin A deficiency can impair dim-light vision. Vitamin D deficiency disrupts bone mineralisation, while vitamin K deficiency interferes with coagulation. A single malabsorption problem can therefore create several apparently unrelated symptoms. The pattern is more informative than any one symptom considered in isolation.
411. Assertion: Deficiency symptoms do not justify unlimited self-administration of vitamin supplements.
Reason: Excessive intake of some vitamins, particularly fat-soluble vitamins, may lead to harmful accumulation.
ⓐ. Both Assertion and Reason are true, and Reason explains Assertion
ⓑ. Both Assertion and Reason are true, but Reason does not explain Assertion
ⓒ. Assertion is true, but Reason is false
ⓓ. Assertion is false, but Reason is true
Correct Answer: Both Assertion and Reason are true, and Reason explains Assertion
Explanation: Vitamin deficiencies should be corrected using an appropriate diet or medically suitable supplementation. Fat-soluble vitamins can be stored in the liver and adipose tissue rather than being rapidly eliminated. Prolonged intake far above requirement may therefore produce hypervitaminosis and tissue damage. Even water-soluble supplements are not automatically harmless at every dose. The possibility of accumulation directly supports the caution expressed in the Assertion.
412. Complete the deficiency relationship correctly:
\[
\text{Vitamin D deficiency}\Rightarrow
\begin{cases}
\underline{\hspace{1.4cm}} & \text{in children}\\
\underline{\hspace{1.4cm}} & \text{in adults}
\end{cases}
\]
ⓐ. scurvy; beriberi
ⓑ. osteomalacia; rickets
ⓒ. night blindness; xerophthalmia
ⓓ. rickets; osteomalacia
Correct Answer: rickets; osteomalacia
Explanation: Growing bones in children are especially affected by defective mineralisation, producing rickets. In adults, inadequate mineralisation or demineralisation of mature bone produces osteomalacia. Both conditions are linked with insufficient vitamin D activity, but their names differ with age and skeletal development. The relationship should not be reversed. Scurvy and beriberi arise from deficiencies of vitamins C and \(\mathrm{B_1}\), respectively.
413. Regular exposure of skin to suitable sunlight can contribute to:
ⓐ. formation of vitamin D-related compounds
ⓑ. direct synthesis of vitamin C from glucose in every person
ⓒ. conversion of vitamin K into vitamin A
ⓓ. production of vitamin \(\mathrm{B_{12}}\) from cobalt in skin
Correct Answer: formation of vitamin D-related compounds
Explanation: Ultraviolet radiation in sunlight can initiate chemical changes in suitable precursors present in the skin. These processes contribute to the body’s vitamin D supply. Sunlight exposure is therefore biologically relevant to calcium and phosphate regulation and bone health. It does not produce every vitamin and cannot replace a balanced diet. Excessive exposure also carries risks, so the relationship is not a justification for unlimited sunlight exposure.
414. Which food-preparation practice is most likely to preserve vitamin C in vegetables?
ⓐ. cutting them finely, soaking them for a long time and discarding the water
ⓑ. boiling them repeatedly in large volumes of water
ⓒ. using brief cooking with minimal water and limited exposure to air
ⓓ. keeping them warm for many hours after cooking
Correct Answer: using brief cooking with minimal water and limited exposure to air
Explanation: Vitamin C is water-soluble and may leach into cooking water. It is also sensitive to prolonged heating and oxidation. Brief cooking with little water reduces the time and solvent volume available for nutrient loss. Limiting exposure to air also decreases oxidative degradation. Finely cutting, soaking and prolonged warming increase rather than reduce the opportunities for vitamin destruction or leaching.
415. The most scientifically appropriate approach to meeting vitamin needs in a healthy person is generally to:
ⓐ. depend only on one highly fortified food
ⓑ. use a balanced diet, with supplements only when indicated
ⓒ. consume unlimited doses because vitamins cannot cause toxicity
ⓓ. avoid all fat-soluble vitamins because they are stored
Correct Answer: use a balanced diet, with supplements only when indicated
Explanation: A balanced diet supplies vitamins together with minerals, macronutrients, fibre and other useful food components. Supplements may be valuable when deficiency, increased requirement, restricted intake or impaired absorption is established. They should not automatically replace varied food intake. Excessive intake can be harmful, particularly for stored fat-soluble vitamins. Avoiding an entire vitamin class would create deficiency rather than improve safety.
416. Hypervitaminosis is more strongly associated with prolonged excessive intake of fat-soluble vitamins because:
ⓐ. they are always converted immediately into proteins
ⓑ. they are absorbed only when no dietary fat is present
ⓒ. they are destroyed before reaching body tissues
ⓓ. they can accumulate in body stores over time
Correct Answer: they can accumulate in body stores over time
Explanation: Vitamins A, D, E and K can be retained in the liver or adipose tissue. Repeated intake above physiological need may therefore increase body stores progressively. Harmful effects can develop when stored concentrations become excessive. Water-soluble vitamins are often eliminated more readily, although excessive supplementation of them is not automatically safe. Storage behaviour explains why dosage and duration both matter for fat-soluble vitamins.
417. A person takes very large doses of vitamins A and D for several months without medical supervision. The principal concern is that:
ⓐ. both vitamins are rapidly excreted unchanged in urine
ⓑ. they may accumulate and produce toxic effects
ⓒ. they will necessarily convert into vitamins B and C
ⓓ. they cannot enter cells because they are fat-soluble
Correct Answer: they may accumulate and produce toxic effects
Explanation: Vitamins A and D are fat-soluble and can be stored within the body. Continued high intake may raise tissue concentrations well beyond normal requirements. Excess vitamin A and excess vitamin D can each produce serious physiological disturbances, although their toxic effects differ. Rapid urinary elimination is more characteristic of many water-soluble substances. Fat solubility promotes absorption with lipids and storage rather than exclusion from cells.
418. The row that correctly combines vitamin source or stability with a nutritional implication is:
| Option | Observation | Implication |
|---|
| A | Vitamin C is water-soluble and oxidation-sensitive | Prolonged washing and cooking may reduce its content |
| B | Vitamin D is fat-soluble | Sunlight has no relationship to its formation |
| C | Vitamins A and D may be stored | Unlimited supplementation is always safe |
| D | Balanced diets contain varied nutrients | They should be replaced completely by vitamin tablets |
ⓐ. Row A
ⓑ. Row B
ⓒ. Row C
ⓓ. Row D
Correct Answer: Row A
Explanation: Vitamin C can dissolve into washing or cooking water and may also undergo oxidative or heat-related loss. Row A therefore connects a chemical property with a realistic food-preparation consequence. Sunlight can contribute to vitamin D formation, so Row B is unacceptable. Storage of vitamins A and D increases rather than removes the risk of excessive intake. Vitamin tablets cannot reproduce the full nutritional composition of a balanced diet.
419. Nucleic acids are best described as:
ⓐ. polymers of amino acids joined by peptide bonds
ⓑ. storage polysaccharides made only from glucose
ⓒ. polynucleotides involved in genetic information
ⓓ. fat-soluble micronutrients required in small amounts
Correct Answer: polynucleotides involved in genetic information
Explanation: Nucleic acids are biological macromolecules constructed from repeating nucleotide units. DNA and RNA are the two major nucleic-acid classes. Their base sequences carry information that can be stored, transmitted or expressed. Proteins are amino-acid polymers, whereas polysaccharides are carbohydrate polymers. Vitamins are regulatory micronutrients rather than polynucleotide chains.
420. The principal hereditary material in most organisms is:
ⓐ. DNA
ⓑ. glycogen
ⓒ. vitamin C
ⓓ. cellulose
Correct Answer: DNA
Explanation: DNA stores hereditary information in the sequence of its nitrogenous bases. This information can be copied and transmitted during cell division and reproduction. In most organisms, DNA serves as the main genetic material. Some viruses use RNA instead, so the statement is not universal for every biological system. Glycogen and cellulose are polysaccharides, while vitamin C is a micronutrient.
