The vitamin that prevents neural tube defects during fetal development is: MCQ with Answer and Explanation

Explanation:
Telomerase is a ribonucleoprotein enzyme that adds repetitive nucleotide sequences to the ends of chromosomes (telomeres), preventing them from shortening during DNA replication. It is highly active in germ cells, stem cells, and most cancer cells, granting them replicative immortality. In most normal somatic cells, telomerase is inactive, leading to gradual telomere shortening and cellular aging.

Explanation:
Parietal (oxyntic) cells in the gastric glands of the stomach secrete hydrochloric acid (HCl), which activates pepsinogen to pepsin, kills bacteria, and provides an acidic pH (1.5-2.0) for protein digestion. Liver produces bile, pancreas secretes digestive enzymes and bicarbonate, goblet cells secrete mucus. Intrinsic factor, required for vitamin B₁₂ absorption, is also secreted by parietal cells.

Explanation:
Plastics are synthetic polymers that resist microbial decomposition and persist in the environment for hundreds of years, causing pollution. Paper, cotton, and vegetable waste are biodegradable and broken down by decomposers.