1. The kidneys are bean-shaped organs that perform several vital functions. Which of the following is NOT a primary function of the kidneys?

A. Filtering waste products from the blood
B. Regulating blood pressure
C. Producing red blood cells
D. Maintaining water balance in the body

Correct answer: C

Rationale: The correct answer is C. While the kidneys perform multiple vital functions, such as filtering waste products from the blood, regulating blood pressure, and maintaining water balance in the body, they do not produce red blood cells. Red blood cell production occurs in the bone marrow, specifically in the spongy tissue called the red bone marrow. Therefore, the kidneys' primary functions do not include producing red blood cells.

2. What is the term for a solution that has a higher concentration of solute compared to another solution?

A. Saturated solution
B. Unsaturated solution
C. Dilute solution
D. Concentrated solution

Correct answer: d

Rationale: A concentrated solution has a higher concentration of solute compared to another solution. The other choices do not accurately describe a concentrated solution.

3. How does an unbalanced force affect an object at rest?

A. It maintains the object's state of rest
B. It does not affect the object's rest
C. It moves the object into motion
D. It decreases the object's mass

Correct answer: c

Rationale: An unbalanced force acting on an object at rest causes it to start moving.

4. What is the acceleration of an object moving at a constant speed of 20 m/s if it comes to a complete stop within 5 seconds?

A. 0 m/s² (no acceleration)
B. 4 m/s²
C. -4 m/s²
D. Information insufficient

Correct answer: C

Rationale: The acceleration can be calculated using the formula: acceleration = (final velocity - initial velocity) / time. In this case, the final velocity is 0 m/s (as the object comes to a complete stop), the initial velocity is 20 m/s, and the time taken is 5 seconds. Plugging these values into the formula, we get acceleration = (0 m/s - 20 m/s) / 5 s = -20 m/s / 5 s = -4 m/s². Therefore, the acceleration is -4 m/s².

5. Which of the following is the main function of the lungs?

A. To transport oxygen and nutrients throughout the body
B. To coordinate movement and sensory information
C. To filter waste products from the blood
D. To exchange oxygen and carbon dioxide between the body and the environment

Correct answer: D

Rationale: Rationale: A) To transport oxygen and nutrients throughout the body - While the lungs do play a role in transporting oxygen, their primary function is to exchange oxygen and carbon dioxide between the body and the environment. The transportation of oxygen and nutrients throughout the body is primarily carried out by the circulatory system, specifically the blood vessels. B) To coordinate movement and sensory information - This function is primarily carried out by the nervous system, specifically the brain and spinal cord. C) To filter waste products from the blood - The kidneys are responsible for filtering waste products from the blood, not the lungs. The lungs primarily function in gas exchange.

6. How many bones are there in the adult human skeleton?

A. 126
B. 206
C. 300
D. 525

Correct answer: D

Rationale: The correct answer is D: 525. The adult human skeleton consists of 206 bones. However, when accounting for individual bones, many of them are paired (like the ribs and vertebrae), bringing the total count to 206 individual bones but 525 in total when considering pairs. This includes bones in the skull, spine, ribs, arms, hands, pelvis, legs, and feet. So, while there are 206 individual bones, the total number of bones in the adult human skeleton is 525 when considering pairs.