1. What is the function of arrector pili muscles?

A. To control sweat production
B. To contract and cause goosebumps
C. To produce sebum
D. To sense touch

Correct answer: B

Rationale: The correct answer is B: 'To contract and cause goosebumps.' Arrector pili muscles are small muscles attached to hair follicles in the skin. When these muscles contract, they cause the hair to stand upright, resulting in the appearance of goosebumps. This physiological response is a remnant of our evolutionary past when our ancestors had more hair, and the raised hair helped to trap air for insulation or to make them look larger when threatened. Therefore, the function of arrector pili muscles is not to control sweat production (A), produce sebum (C), or sense touch (D), but rather to create the physical response of goosebumps.

2. Adipose tissue, commonly known as fat, primarily functions in:

A. Support
B. Insulation
C. Energy storage
D. All of the above

Correct answer: D

Rationale: The correct answer is D, 'All of the above.' Adipose tissue, or fat, serves multiple functions in the body. It provides support by cushioning and protecting organs, acts as an insulation layer to maintain body temperature, and serves as a crucial energy storage site where excess energy is stored in the form of triglycerides. Therefore, all of the options listed (support, insulation, and energy storage) are accurate functions of adipose tissue.

3. Which vitamin is essential for proper absorption of calcium and plays a role in lung function?

A. Vitamin A
B. Vitamin B12
C. Vitamin D
D. Vitamin E

Correct answer: C

Rationale: The correct answer is C, Vitamin D. Vitamin D is essential for the proper absorption of calcium in the intestines, which is crucial for maintaining strong bones and teeth. Additionally, Vitamin D plays a role in lung function by supporting respiratory health and reducing inflammation in the lungs. Vitamin A is important for vision and immune function, Vitamin B12 is necessary for red blood cell formation and neurological function, and Vitamin E is an antioxidant that helps protect cells from damage.

4. 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.

5. Which of the following is the main function of the small intestine?

A. To store food and break it down into smaller pieces
B. To absorb nutrients into the bloodstream
C. To produce enzymes that help digest food
D. To eliminate waste products from the body

Correct answer: B

Rationale: Rationale: The small intestine is a crucial part of the digestive system where the majority of nutrient absorption takes place. It is lined with tiny finger-like projections called villi that increase the surface area for absorption. The small intestine absorbs nutrients such as carbohydrates, proteins, fats, vitamins, and minerals from the digested food into the bloodstream to be transported to cells throughout the body for energy, growth, and repair. Options A, C, and D do not accurately describe the main function of the small intestine.

6. When magnesium metal reacts with hydrochloric acid, hydrogen gas is produced. What evidence suggests a chemical reaction is occurring?

A. A change in color
B. The formation of a gas
C. Dissolving in a liquid
D. No change in temperature

Correct answer: B

Rationale: The correct answer is B: 'The formation of a gas.' When magnesium metal reacts with hydrochloric acid, hydrogen gas is produced as one of the products. The formation of a gas is a clear indicator of a chemical reaction taking place. This is known as a gas evolution reaction, where a gas is produced as a result of a chemical reaction. The other options do not specifically indicate a chemical reaction. A change in color or dissolving in a liquid could occur in physical changes as well, and no change in temperature does not necessarily rule out a chemical reaction as some reactions are endothermic or exothermic.