1. The longest bone in the human body is the:

A. Tibia
B. Fibula
C. Femur
D. Humerus

Correct answer: C

Rationale: The correct answer is C: "Femur." The femur is the longest bone in the human body, located in the thigh region and connecting the hip to the knee. It plays a crucial role in supporting the body's weight and facilitating movement. The tibia and fibula are bones in the lower leg, while the humerus is a bone in the upper arm. Therefore, the femur is the correct answer for the longest bone in the human body.

2. Which of the following is an example of a polymer?

A. Methane
B. Ethanol
C. Polyethylene
D. Acetic acid

Correct answer: C

Rationale: Polyethylene is a polymer, consisting of a large number of repeating ethylene units. The other choices represent small organic compounds.

3. Which digestive enzyme is primarily responsible for breaking down proteins?

A. Pepsin
B. Lipase
C. Amylase
D. Maltase

Correct answer: A

Rationale: The correct answer is A: Pepsin. Pepsin is primarily responsible for breaking down proteins in the stomach. It is an enzyme produced by the gastric chief cells in the stomach lining and works in a highly acidic environment to break down proteins into smaller peptide fragments. Lipase, on the other hand, is responsible for breaking down fats, amylase for breaking down carbohydrates, and maltase for breaking down maltose (a type of sugar). Therefore, pepsin is the correct enzyme involved in the digestion of proteins.

4. Which of the following questions is NOT appropriate for scientific investigation?

A. How can we reduce greenhouse gas emissions?
B. Is there intelligent life beyond Earth?
C. What is the meaning of life?
D. Does free will exist?

Correct answer: C

Rationale: Science deals with observable, measurable phenomena using evidence-based methods. Questions about subjective experiences and abstract concepts like meaning fall outside the realm of scientific inquiry.

5. Which division of the autonomic nervous system is responsible for the "rest and digest" response, promoting relaxation and conservation of energy?

A. Sympathetic nervous system
B. Parasympathetic nervous system
C. Somatic nervous system
D. Central nervous system

Correct answer: b

Rationale: The correct answer is B, the parasympathetic nervous system. This division of the autonomic nervous system is responsible for the "rest and digest" response, promoting relaxation and conservation of energy. When activated, it slows the heart rate, increases digestion, and helps the body rest and recover. The sympathetic nervous system, on the other hand, is responsible for the "fight or flight" response, preparing the body for action. The somatic nervous system controls voluntary movements, and the central nervous system consists of the brain and spinal cord, coordinating all nervous system functions.