The term 'malnutrition' refers to: MCQ with Answer and Explanation

Explanation:
Mitosis produces two genetically identical diploid daughter cells (clones) essential for growth, repair, and asexual reproduction. Meiosis involves pairing (synapsis) and crossing over during prophase I, and produces four genetically diverse haploid cells (gametes). The conservation of chromosome number and genetic identity is a hallmark of mitosis.

Explanation:
Uracil replaces thymine in RNA. In DNA, thymine pairs with adenine; in RNA, uracil pairs with adenine. Adenine, guanine, and cytosine are present in both. The presence of uracil and the sugar ribose (vs. deoxyribose) are key structural differences between RNA and DNA.

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).