The smallest bone in the human body is the: MCQ with Answer and Explanation

Explanation:
Mature plant cells contain a large central vacuole that stores water, ions, pigments, and waste products, and is critical for maintaining turgor pressure against the cell wall, providing structural support. The vacuole can occupy up to 90% of cell volume. The reason correctly explains the function of the vacuole, so both statements are true and linked.

Explanation:
Charles Darwin proposed the theory of evolution by natural selection, where organisms with favorable traits survive and reproduce. Homologous organs share a common structural plan and evolutionary origin, indicating divergent evolution from a common ancestor. Evolution does not lead to perfection; it only results in adaptation to the current environment. Thus, statements 1 and 3 are correct.

Explanation:
Vaccines induce active immunity (antibodies + memory). Active takes time, passive is immediate but no memory. Innate is nonspecific.