Assertion (A): Genetic variation is essential for evolution. Reason (R): Without variation, natural selection cannot occur because there are no differences to select from. MCQ with Answer and Explanation

Explanation:
Lipase, produced by the pancreas, breaks down dietary fats (triglycerides) into monoglycerides and free fatty acids, aided by bile salts.

Explanation:
Glyoxysomes are specialized peroxisomes found in the fat-storing cotyledons of germinating seeds. They contain enzymes for the beta-oxidation of fatty acids and the glyoxylate cycle, which converts stored lipids into carbohydrates (gluconeogenesis) to nourish the growing seedling. This metabolic pathway is absent in animal cells. Exam tip: Glyoxysomes eventually transform into chloroplasts as the plant matures.

Explanation:
The variable (V) region at the tips of the antibody Y-shape contains the antigen-binding site, which is specific to a particular antigen. The constant region determines the class (IgG, IgM, etc.) and effector functions. The Fc region binds to immune cell receptors. Variability in the V region is generated by gene rearrangement, allowing immense antibody diversity.