The vitamin that is essential for the synthesis of collagen is: MCQ with Answer and Explanation

Explanation:
Proteins are complex macromolecules composed of long chains of amino acids linked by peptide bonds. Fats (triglycerides) are lipids composed of one glycerol molecule esterified to three fatty acid chains. Carbohydrates are composed of simple sugars (monosaccharides) like glucose, not fatty acids. Thus, statements 1 and 3 are correct, while statement 2 is false.

Explanation:
PCR involves repeated cycles of high-temperature denaturation (around 94°C) to separate the DNA strands. Normal DNA polymerases would be destroyed at these temperatures. Therefore, a thermostable DNA polymerase is required. Taq polymerase, isolated from the thermophilic bacterium Thermus aquaticus found in hot springs, is the most commonly used enzyme because it can withstand the high denaturation temperatures without losing its activity, eliminating the need to add fresh enzyme after each cycle.

Explanation:
Humans are ureotelic—they excrete nitrogenous waste mainly as urea, which is less toxic than ammonia and requires moderate water for excretion. Ammonia is excreted by aquatic animals, uric acid by birds and reptiles (to conserve water), and creatinine is also excreted but is a minor component compared to urea.