Which of the following statements about protein structure is correct? MCQ with Answer and Explanation

Explanation:
The medulla oblongata is the lowest part of the brainstem, connecting the pons to the spinal cord. It contains vital autonomic centers that control essential, involuntary life-sustaining functions. These include the cardiovascular center (regulating heart rate and blood vessel diameter), the respiratory center (regulating the rate and depth of breathing), and reflex centers for vomiting, coughing, sneezing, and swallowing. Damage to the medulla is often fatal due to the cessation of these vital functions.

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:
Human somatic cells are diploid (2n = 46), with 23 pairs of homologous chromosomes. Gametes (sperm and egg) are haploid (n = 23), containing one set of chromosomes. Fertilization restores diploidy. The haploid number is 23. Option 22 would be autosomes plus one sex chromosome, but the total count is 23. 44 is the number of autosomes in somatic cells.