Different types of skeletal systems have developed adaptive features suitable to an organism's way of life. With reference to the above statement: (i) State the types of skeletal system found in crabs and humans. (ii) Describe how the skeletal system of crabs and humans is suitable in the environment it lives in. (iii) State one disadvantage each of skeletal system found in crabs and humans.
Answer (1)
(i) Types of Skeletal System :
Crabs : Crabs have an exoskeleton, which is a hard outer shell providing support and protection.
Humans : Humans have an endoskeleton, which is an internal skeleton made up of bones.
(ii) Adaptation of Skeletal Systems :
Crabs : The exoskeleton of crabs is made of chitin and calcium carbonate, which provides a tough armor that protects them from predators and environmental hazards. This shell also supports muscle attachment, facilitating movement and strength in water for activities such as walking, swimming, and burrowing. The exoskeleton is ideal for an aquatic environment, as it contributes to buoyancy as well.
Humans : The endoskeleton in humans provides a sturdy structure that supports the body’s muscles and organs. It is flexible and enables a wide range of movements due to the presence of joints. The skeletal system also allows for growth without needing to molt, which is important for humans who constantly grow and develop. Additionally, bones store minerals and produce blood cells, which are crucial for survival in various environments.
(iii) Disadvantages :
Crabs : One disadvantage of an exoskeleton is the necessity for molting. Crabs must periodically shed their exoskeleton to grow, which leaves them vulnerable to predators during this process.
Humans : A disadvantage of the endoskeleton is that being composed of bones, it can break under significant stress or impact. Healing from such injuries can be a long and painful process.
