The process of physical and chemical breakdown of food into absorbable form is: MCQ with Answer and Explanation

Explanation:
Intrinsic factor, a glycoprotein secreted by gastric parietal cells, binds to vitamin B₁₂ and facilitates its absorption in the ileum. Absence or deficiency (pernicious anemia) leads to B₁₂ deficiency, causing megaloblastic anemia and neurological symptoms. HCl activates pepsin, pepsinogen is precursor, mucus protects.

Explanation:
Primary consumers are herbivores that feed directly on producers (plants). Grasshopper feeds on grass/plants, thus a primary consumer. Lion and eagle are secondary/tertiary consumers (carnivores). Fungi are decomposers. In a food chain: Grass (producer) → Grasshopper (primary consumer) → Frog (secondary consumer) → Snake (tertiary consumer) → Eagle (quaternary consumer). Energy flows unidirectionally.

Explanation:
Enzymes speed up reactions by lowering activation energy and are not consumed; they remain unchanged after the reaction. Thus, statement 2 is false. 1 and 3 are correct.