Which of the following is an algal biofertilizer used in rice fields? MCQ with Answer and Explanation

Explanation:
While the Blood-Brain Barrier (BBB) protects most of the brain, there are specific areas where the BBB is absent or highly permeable. These are the circumventricular organs (CVOs), which are located around the third and fourth ventricles. Because they lack a typical BBB, they can directly sample the chemical composition of the blood and cerebrospinal fluid. This is essential for their functions, which include neuroendocrine regulation (e.g., the area postrema for vomiting, the organum vasculosum of the lamina terminalis for osmoregulation, and the median eminence for hormone release).

Explanation:
Vitamin B₁₂ (cobalamin) contains a cobalt ion at the center of its corrin ring. It is the only vitamin that contains a metal. Iron is in heme, zinc in enzymes, magnesium in chlorophyll.

Explanation:
Iron-deficiency anemia is the most prevalent nutritional deficiency worldwide, characterized by fatigue, pallor, and reduced oxygen-carrying capacity. It is treated with iron supplementation and dietary changes.