Identify the INCORRECT statement about the human skeleton: MCQ with Answer and Explanation

Explanation:
Sponges are the simplest multicellular animals with a cellular level of organization (no true tissues or organs). They are mostly marine, sessile, filter feeders. Water enters through numerous pores (ostia) into a spongocoel and exits through the osculum. They lack a nervous system. They possess specialized cells like choanocytes and amoebocytes but no coordination.

Explanation:
Coral reefs grow by accumulation of calcium carbonate skeletons secreted by living coral polyps, but the reef structure itself is non-living. It increases in mass externally (accretion). Mushrooms, mango trees, and bacteria exhibit intrinsic growth by cell division, characteristic of living organisms. Thus, coral reef growth is non-living accumulation.

Explanation:
The ball and socket joint (e.g., glenohumeral, hip) allows movement in multiple axes (flexion, extension, abduction, adduction, rotation). The rounded head of one bone fits into the cup-shaped socket of another. Hinge (elbow, knee) allows movement in one plane, pivot (neck) allows rotation, gliding (wrist) allows sliding.