Which of the following body systems is not needed for survival?

• A. Endocrine
• B. Reproductive
• C. Digestive
• D. Exocrine

Answer: (B)

The key idea is that some body systems are essential for keeping a person alive, while others are focused on reproduction and are not required for immediate survival. The endocrine system coordinates hormones that regulate metabolism, growth, temperature, and responses to stress—keeping the body's processes in balance. The digestive system turns food into usable energy and nutrients, so cells can function and stay alive. Exocrine glands provide secretions through ducts, such as digestive enzymes and saliva, which support digestion and protective functions that are important for staying healthy. The reproductive system, however, mainly serves the purpose of producing offspring and is not necessary for an individual to survive. So, the reproductive system is the one not needed for survival.