In the human digestive system, the 'Villi' of the small intestine are covered with even smaller, microscopic projections on the epithelial cells called: MCQ with Answer and Explanation

Explanation:
Plague is caused by Yersinia pestis and transmitted to humans by the bite of infected fleas (from rodents), thus vector-borne. Common cold is airborne, typhoid is water/food-borne, tetanus enters through wounds from soil. Other vector-borne diseases include malaria (mosquito), dengue (mosquito), Lyme disease (tick).

Explanation:
A balanced diet contains all the essential macronutrients (carbohydrates, proteins, fats) and micronutrients (vitamins, minerals) in the correct proportions required for optimal health, growth, and maintenance. Malnutrition is a broad term that refers to deficiencies, excesses, or imbalances in a person's intake of energy and/or nutrients; it includes both undernutrition (wasting, stunting) and overnutrition (overweight, obesity). Water is an essential nutrient, crucial for hydration, transport, and all biochemical reactions. Thus, statements 1 and 3 are correct.

Explanation:
While most arteries carry oxygenated blood, the pulmonary artery carries deoxygenated blood from the heart to the lungs. Veins possess valves along their length to ensure unidirectional blood flow back to the heart against gravity. Capillaries are composed of a single layer of endothelial cells (thin walls) to facilitate the exchange of gases and nutrients. Only statement 2 is universally correct.