1. What is the primary function of hair on the human body?

A. Insulation
B. Sensory perception
C. Protection
D. Vitamin D synthesis

Correct answer: A

Rationale: The primary function of hair on the human body is insulation. Hair acts as a protective layer to help regulate body temperature by trapping heat close to the skin. This insulation property is especially important in colder climates to prevent excessive heat loss from the body. While hair can also provide some level of protection from external elements and minor injuries, its main role is to insulate the body. Sensory perception is mainly attributed to nerve endings in the skin rather than hair. Vitamin D synthesis is primarily dependent on exposure to sunlight rather than hair. Therefore, option A, insulation, is the correct answer.

2. A substance that can donate a hydroxide ion (OH-) in solution is classified as a:

A. Salt
B. Base
C. Neutral compound
D. Dehydrating agent

Correct answer: B

Rationale: Bases accept protons (H+) and can donate hydroxide ions

3. Identify the predicate in the following sentence: "The children built a sandcastle on the beach."

A. on the beach
B. built a sandcastle
C. children
D. the

Correct answer: B

Rationale: The predicate is the verb and any words following it that describe the action or state of being of the subject.

4. You need to repaint a cylindrical water tank with a diameter of 2 meters and a height of 3 meters. Assuming one can of paint covers 10 sq m, how many cans do you need (consider only the exterior surface)?

A. 6 cans
B. 9 cans
C. 12 cans
D. 15 cans

Correct answer: C

Rationale: Calculate the surface area of the cylinder and divide by the coverage area per can.

5. What is the protective fluid that surrounds the brain and spinal cord?

A. Blood
B. Cerebrospinal fluid
C. Myelin sheath
D. Insulin

Correct answer: B

Rationale: The correct answer is B: Cerebrospinal fluid. This fluid acts as a cushion for the brain and spinal cord, providing protection from impacts. Blood is essential for transporting nutrients and oxygen, but it does not directly surround or protect these vital nervous system structures. Myelin sheath is a fatty substance that insulates nerve fibers, not the fluid surrounding the nervous system. Insulin is a hormone involved in regulating blood sugar levels and is not related to protecting the brain and spinal cord.