Which of the following statements about the human skeleton is correct? MCQ with Answer and Explanation

Explanation:
Passive diffusion is the net movement of molecules down their concentration gradient without energy. Osmosis is water diffusion, active transport uses energy, endocytosis is vesicular uptake.

Explanation:
The placenta exchanges nutrients, gases, and wastes between mother and fetus. Sperm are produced in testes, fertilization is in the fallopian tube, testosterone by Leydig cells.

Explanation:
Fossils are direct evidence showing transitional forms. Lamarck proposed use and disuse, not natural selection. Analogous organs do not indicate common ancestry; homologous do. Appendix is vestigial.