Question

All animals possess both endoskeleton and exoskeleton.
A. False
B. True

Answer 1

Hint: A skeleton helps in functions such as motion and locomotion and muscular growth (it gives structural support to humans, birds, animals, etc.,) and makes it easier for movement and locomotion, and also protects the internal organs. It can be external (exoskeleton) or internal (endoskeleton). Some living organisms contain an endoskeleton, some contain an exoskeleton, and some also contain both.

Complete step-by-step answer:
Endoskeleton is an internal skeleton that exists inside the body of a living organism, e.g., a bony or a cartilaginous skeleton of vertebrates. All vertebrates such as mammalians, amphibians, reptiles, fish, and birds contain an endoskeleton.
The endoskeleton includes cartilage and bones. In some organisms such as cartilaginous fishes, it is exclusively composed of cartilage. Bones are composed of bone cells referred to as osteoblasts and they form joints to formulate one another. A bone is connected to another bone by ligament and muscles are connected to bones by tendons.
The exoskeleton is the external skeleton that is present on the external surface of an organism. Most animals or invertebrates do not have a backbone, but they have exoskeletons, e.g., cockroaches, grasshoppers, and crustaceans such as lobsters and crabs. Insects are the biggest group in the animal kingdom that contains an exoskeleton composed of a substance known as chitin. Their wings are connected to the exoskeleton through muscles.

Hence, the statement All animals possess both endoskeleton and exoskeleton is false.

Note: Skeleton cells in the embryonic stage migrate to either stage and produce exoskeleton or endoskeleton but never both.