1. Which of the following minerals is important for bone health and is stored in bones by the skeletal system?

A. Iron
B. Sodium
C. Calcium
D. Magnesium

Correct answer: C

Rationale: The correct answer is C: Calcium. Calcium is essential for maintaining strong and healthy bones. It is a key mineral stored in bones by the skeletal system, where it provides structural support and strength. Adequate calcium intake is crucial for preventing bone diseases like osteoporosis and ensuring proper bone formation and density. Iron (A), Sodium (B), and Magnesium (D) are important minerals for various bodily functions but are not primarily responsible for bone health and storage in bones by the skeletal system.

2. Repeating decimals can be expressed as fractions. Which of the following represents the decimal 0.7777... as a fraction?

A. 77/1000
B. 70/99
C. 777/900
D. 7/9

Correct answer: C

Rationale: Let x equal the decimal. Set up two equations such that the digits after the decimal point are identical. 1000x = 777.7777... 10x = 7.7777... Subtracting the two equations, we have 990x = 770. Dividing both sides by 990 gives us x = 770/990, which can be simplified to 77/90.

3. Hematopoietic tissue is responsible for

A. Building and repairing bone
B. Supporting and connecting tissues
C. Production of blood cells
D. Contracting for movement

Correct answer: C

Rationale: Hematopoietic tissue is responsible for the production of blood cells. This specialized tissue is found in the bone marrow and is crucial for the continuous generation of red blood cells, white blood cells, and platelets. These blood cells play essential roles in oxygen transport, immune defense, and blood clotting. Building and repairing bone (option A) is primarily the function of osteoblasts and osteoclasts in bone tissue. Supporting and connecting tissues (option B) is the role of connective tissues like tendons and ligaments. Contracting for movement (option D) is the function of muscle tissue. Therefore, the correct answer is C, as hematopoietic tissue specifically focuses on blood cell production.

4. What happens to the frequency of a wave when its wavelength is doubled, assuming the speed remains constant?

A. Frequency remains the same.
B. Frequency is halved.
C. Frequency is doubled.
D. Frequency information is insufficient to determine.

Correct answer: C

Rationale: Since the wave speed is constant, if the wavelength increases, the frequency must decrease to maintain the same energy transfer per unit time.

5. The muscular tube that connects the mouth to the stomach is called the:

A. Pharynx
B. Esophagus
C. Trachea
D. Larynx

Correct answer: B

Rationale: The correct answer is B: Esophagus. The esophagus is the muscular tube that connects the mouth to the stomach. It plays a crucial role in transporting food from the mouth to the stomach through peristaltic movements. The pharynx is the part of the throat that connects the mouth and nasal cavity to the esophagus and trachea. The trachea, also known as the windpipe, is responsible for carrying air to and from the lungs. The larynx, commonly known as the voice box, is involved in producing sound and protecting the trachea during swallowing. Therefore, the esophagus is specifically responsible for food transport from the mouth to the stomach.

6. he shimmering image of water seen on a hot road is a well-known example of:

A. Reflection
B. Refraction
C. Interference
D. Polarization

Correct answer: B

Rationale: The shimmering image of water seen on a hot road is a classic example of refraction. Refraction occurs when light waves pass from one medium to another, causing them to change direction due to the change in speed. In this scenario, the air above the road is hotter than the air closer to the ground, creating different densities of air which causes light to bend and distort, giving the illusion of water. Reflection, on the other hand, is the bouncing back of light waves from a surface, interference involves the superposition of two or more waves, and polarization is the orientation of light waves in a specific direction. Therefore, option B, refraction, is the correct answer in this case.