The deficiency disease 'pellagra' is caused by lack of: MCQ with Answer and Explanation

Explanation:
The medulla oblongata, part of the brainstem, contains vital centers that control respiration, heart rate, and blood pressure. It also regulates reflex actions like coughing, swallowing, and vomiting. The cerebrum is for voluntary actions and thinking, cerebellum for coordination, and hypothalamus for homeostasis and endocrine control.

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 Bohr effect describes how an increase in pCO2 or a decrease in pH (increase in H+) reduces hemoglobin's affinity for oxygen, shifting the oxygen dissociation curve to the right and promoting oxygen unloading. Conversely, in the lungs, where pCO2 is low and pH is relatively higher (more alkaline), the Bohr effect works in reverse: hemoglobin's affinity for oxygen increases, facilitating the loading (binding) of oxygen to hemoglobin. The Haldane effect describes the reciprocal relationship for CO2 transport.