Final answer:
Arachnids, which have an exoskeleton, must shed and then regenerate their skeletal system as they grow, a process known as molting. Unlike endoskeletons that expand with growth, an exoskeleton must be periodically shed to allow for size increase.
Step-by-step explanation:
Skeletal System and Shedding
The skeletal system is essential for providing support, shape, and protection to the body, as well as allowing for movement and growth. There are different types of skeletal structures, such as hydrostatic skeletons, exoskeletons, and endoskeletons. Organisms with an exoskeleton, such as arachnids, must shed their external skeleton to grow in a process known as molting. Unlike endoskeletons, which can grow with the organism, an exoskeleton does not expand and must be periodically shed for the organism to increase in size.
In response to the student's question on which of the following organisms must shed and then regenerate its skeletal system as it grows, the answer is c) Arachnids. Arachnids, including spiders and scorpions, have an exoskeleton, a hardened outer shell that provides protection and support but limits growth. Therefore, they undergo molting to shed this outer layer and produce a new, larger exoskeleton to accommodate their growing bodies.