The vitamin whose active form, retinol, is essential for vision is: 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:
Evolution, at its most fundamental genetic level, is defined as the change in the frequency of alleles within a population over successive generations. Speciation is the evolutionary process by which populations evolve to become distinct, reproductively isolated species. Evolution does not have a predetermined goal or direction towards complexity; it simply results in adaptation to the current environment, which can sometimes lead to simpler forms (like parasites losing complex structures). Thus, statements 1 and 2 are correct.

Explanation:
The vertebral column (spine) consists of vertebrae stacked to form a canal that encloses and protects the spinal cord. The skull protects the brain, rib cage the thoracic organs, pelvis the pelvic organs.