What is a major disadvantage of an exoskeleton in eukaryotic organisms?

• A. It provides less protection against physical damage compared to an endoskeleton.
• B. It increases the efficiency of gas exchange.
• C. It limits the growth of the organism, requiring periodic molting.
• D. It allows for unlimited flexibility and movement.

Answer: (C)

Verified step by step guidance

1. Understand the concept of an exoskeleton: An exoskeleton is a rigid external covering that provides structural support and protection to certain organisms, such as arthropods. It differs from an endoskeleton, which is an internal support structure found in vertebrates.
2. Identify the primary disadvantage of an exoskeleton: While it offers protection and support, the rigidity of the exoskeleton limits the organism's ability to grow continuously. To accommodate growth, organisms with exoskeletons must periodically shed their old exoskeleton in a process called molting.
3. Explain molting: During molting, the organism sheds its old exoskeleton and forms a new, larger one. This process leaves the organism temporarily vulnerable to predators and environmental hazards until the new exoskeleton hardens.
4. Compare the exoskeleton to an endoskeleton: Unlike an exoskeleton, an endoskeleton grows with the organism, eliminating the need for molting and providing continuous protection and support.
5. Conclude the major disadvantage: The need for periodic molting due to the growth limitation imposed by the exoskeleton is a significant disadvantage compared to the continuous growth and protection offered by an endoskeleton.