Question 1

Which of the following vitamins is synthesized by the human body when skin is exposed to sunlight?

Accepted Answer

Vitamin D is synthesized in the skin when exposed to ultraviolet B (UVB) radiation from sunlight. This is why it is often called the 'sunshine vitamin.' The synthesis occurs in the epidermis and dermis layers of the skin.

Question 2

Beriberi is a deficiency disease caused by the lack of which vitamin?

Accepted Answer

Beriberi is caused by deficiency of Vitamin B1 (thiamine). This disease affects the nervous system and heart, causing weakness, nerve damage, and in severe cases, heart failure. It was historically common in populations consuming polished white rice without thiamine-rich bran.

Question 3

Which of the following is a water-soluble vitamin that acts as a coenzyme in energy metabolism?

Accepted Answer

Vitamin B1 (thiamine) is a water-soluble vitamin that functions as a coenzyme (thiamine pyrophosphate) in carbohydrate metabolism and energy production. Water-soluble vitamins cannot be stored in the body and must be obtained regularly from diet.

Question 4

Scurvy is a deficiency disease caused by lack of which vitamin?

Accepted Answer

Scurvy is caused by deficiency of Vitamin C (ascorbic acid). This disease affects collagen synthesis, leading to bleeding gums, poor wound healing, and weakened connective tissue. It was historically common among sailors on long voyages without access to fresh fruits and vegetables.

Question 5

Which mineral is essential for the formation of hemoglobin and oxygen transport in the blood?

Accepted Answer

Iron is the essential mineral required for hemoglobin formation. Iron is a component of the heme group in hemoglobin, which binds oxygen in the lungs and releases it in tissues. Iron deficiency leads to anemia, characterized by reduced oxygen-carrying capacity of blood.

Question 6

Which of the following is the primary mode of transmission for Malaria?

Accepted Answer

Malaria is transmitted through the bite of infected female Anopheles mosquitoes. The parasite (Plasmodium) is transmitted from the mosquito's salivary glands into the human bloodstream during a blood meal. This is a vector-borne disease.

Question 7

Scurvy is a deficiency disease caused by the lack of which vitamin, and which body system is primarily affected?

Accepted Answer

Scurvy is caused by Vitamin C (ascorbic acid) deficiency. Vitamin C is essential for collagen synthesis, which is critical for maintaining the integrity of connective tissues, blood vessels, and skin. The disease primarily affects the skeletal and circulatory systems, causing bleeding gums, poor wound healing, and weakened bones.

Question 8

Kwashiorkor is a severe form of malnutrition characterized by deficiency of which macronutrient?

Accepted Answer

Kwashiorkor is a form of protein-energy malnutrition (PEM) caused primarily by severe protein deficiency, often with adequate or near-adequate calorie intake. It is characterized by edema, fatty liver, skin lesions, and hair discoloration. The condition is common in developing countries, particularly in young children after weaning.

Question 9

Which of the following vitamins is primarily responsible for calcium absorption in the human body and is synthesized when skin is exposed to sunlight?

Accepted Answer

Vitamin D is essential for calcium absorption in the intestines and is synthesized in the skin upon exposure to ultraviolet B (UVB) radiation from sunlight. This is why it is often called the 'sunshine vitamin.' Vitamin D deficiency leads to rickets in children and osteomalacia in adults.

Question 10

Which vitamin deficiency causes Beriberi, a disease affecting the nervous system and heart?

Accepted Answer

Beriberi is caused by deficiency of Vitamin B1 (Thiamine). This disease was historically common in populations consuming polished rice as a staple, as the thiamine-rich outer layers were removed during processing.

Question 11

Kwashiorkor is a severe form of protein-energy malnutrition. Which of the following is NOT a characteristic clinical feature of Kwashiorkor?

Accepted Answer

Kwashiorkor is characterized by edema, hepatomegaly, skin lesions, hair changes, and apathy. However, it does NOT typically present with severe muscle wasting (that is characteristic of Marasmus). Kwashiorkor patients often appear 'puffy' due to edema despite being malnourished.

Question 12

Scurvy, a disease caused by Vitamin C deficiency, primarily affects collagen synthesis. Which of the following is the biochemical reason for impaired collagen formation in Scurvy?

Accepted Answer

Vitamin C (Ascorbic Acid) is a cofactor for prolyl and lysyl hydroxylase enzymes, which hydroxylate proline and lysine residues in collagen. Without hydroxylation, collagen cannot form stable triple helix structure and cross-links, leading to defective connective tissue.

Question 13

Rickets is a metabolic bone disease in children caused by Vitamin D deficiency. Which of the following is the PRIMARY mechanism by which Vitamin D deficiency leads to defective bone mineralization?

Accepted Answer

Vitamin D is essential for calcium and phosphate absorption in the small intestine. Without adequate Vitamin D, intestinal absorption of calcium decreases, leading to hypocalcemia and secondary hyperparathyroidism. Low serum calcium and phosphate prevent proper mineralization of the bone matrix (osteoid).

Question 14

Pellagra is a disease caused by Vitamin B3 (Niacin) deficiency, characterized by the '4 Ds'. Which of the following is NOT one of the classic '4 Ds' of Pellagra?

Accepted Answer

The classic '4 Ds' of Pellagra are: Dermatitis, Diarrhea, Dementia, and Death (if untreated). Anemia is NOT a primary feature of Pellagra; it is more characteristic of Vitamin B12 or folate deficiency. Pellagra primarily affects the skin, GI tract, and nervous system.

Question 15

Which of the following vitamins is synthesized by the human body and does NOT need to be obtained primarily from dietary sources?

Accepted Answer

Vitamin D is synthesized in the skin upon exposure to ultraviolet (UV) radiation from sunlight. When 7-dehydrocholesterol in the skin is exposed to UVB rays, it converts to previtamin D3, which is then converted to active vitamin D (calcitriol) in the liver and kidneys. While dietary sources exist, the body can produce sufficient amounts endogenously, making it unique among essential vitamins.

SSC GD Constable Diseases & Nutrition

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