1. Maintaining good muscle strength and flexibility as we age becomes important to avoid:

A. Headaches
B. Falls
C. Anxiety
D. Common cold

Correct answer: B

Rationale: The correct answer is B: 'Falls.' Maintaining good muscle strength and flexibility as we age is crucial for preventing falls, which become more common with age and can lead to serious injuries such as fractures. Strong muscles and good flexibility help in maintaining balance and stability, reducing the risk of falls. Headaches, anxiety, and the common cold are not directly related to muscle strength and flexibility, making them less likely to be avoided by focusing on these aspects of physical health.

2. What is the basic unit of heredity?

A. Chromosome
B. Cell
C. Gene
D. Organ

Correct answer: C

Rationale: Rationale: A gene is the basic unit of heredity that carries the instructions for making proteins, which determine an organism's traits. Genes are segments of DNA located on chromosomes within the cell. While chromosomes contain many genes, a gene itself is the fundamental unit of heredity responsible for passing on genetic information from one generation to the next. Cells are the basic structural and functional units of living organisms, but genes specifically carry genetic information. Organs are composed of tissues and serve specific functions within an organism, but they are not the basic unit of heredity.

3. When making a dilution, you...

A. Add more solute to a concentrated solution
B. Change the temperature of the solution
C. Decrease the concentration of a solution
D. All of the above

Correct answer: C

Rationale: The correct answer is C: 'Decrease the concentration of a solution.' When making a dilution, you decrease the concentration of a solution by adding more solvent, not solute. Adding more solute to a concentrated solution would increase the concentration, not dilute it. Changing the temperature of the solution does not directly relate to dilution. Therefore, the only correct statement related to the process of making a dilution is that you decrease the concentration of the solution by adding more solvent, making option C the correct answer.

4. How does an increase in mass affect the force required to produce the same acceleration on an object?

A. Increases force required
B. Decreases force required
C. Has no effect on force required
D. Causes unpredictable changes in force required

Correct answer: a

Rationale: With an increase in mass, more force is needed to produce the same acceleration due to inertia.

5. When a car brakes to a stop, friction between the tires and the road acts as:

A. A balanced force
B. An unbalanced force causing acceleration
C. An unbalanced force causing the car to remain at rest
D. No force at all

Correct answer: B

Rationale: Friction opposes the car's motion, acting as an unbalanced force that decelerates the car and brings it to a stop.

6. The passage implies that achieving energy sustainability requires...

A. solely relying on renewable energy sources for electricity generation.
B. a combination of advancements in renewable energy production and management technologies.
C. prioritizing economic benefits over environmental concerns when making energy choices.
D. focusing solely on reducing energy consumption without addressing production sources.

Correct answer: B

Rationale: The passage emphasizes the need for both increasing renewable energy and managing its fluctuations, suggesting B as the key to sustainability.