1. Coronary arteries are responsible for:

A. Delivering oxygenated blood throughout the body.
B. Supplying oxygenated blood to the heart muscle itself.
C. Carrying deoxygenated blood back to the heart.
D. Regulating blood pressure through vasoconstriction and vasodilation.

Correct answer: B

Rationale: The correct answer is B: 'Supplying oxygenated blood to the heart muscle itself.' Coronary arteries are specialized blood vessels that branch off the aorta and provide oxygenated blood to the heart muscle. This is crucial for the heart to function properly and maintain its own blood supply separate from the systemic circulation. The other options are incorrect because delivering oxygenated blood throughout the body is the role of the systemic circulation and not specific to coronary arteries. Carrying deoxygenated blood back to the heart is the function of veins, while regulating blood pressure through vasoconstriction and vasodilation is primarily controlled by arteries in general, not just the coronary arteries.

2. What property of matter refers to the force of gravity acting on an object?

A. Mass
B. Weight
C. Density
D. Volume

Correct answer: b

Rationale: Weight is the measure of the force of gravity acting on an object. It is calculated as mass multiplied by the acceleration due to gravity.

3. Which of the following is NOT a function of the cilia lining the respiratory tract?

A. Trapping inhaled dust and debris
B. Moistening inhaled air
C. Producing mucus
D. Propelling mucus upwards towards the throat

Correct answer: C

Rationale: The correct answer is C: 'Producing mucus.' Cilia lining the respiratory tract do not produce mucus, but rather move the mucus that is produced by other cells. The cilia work together to propel the mucus upwards towards the throat, where it can be either swallowed or expelled. Trapping inhaled dust and debris, moistening inhaled air, and propelling mucus upwards are all important functions of the cilia in the respiratory tract, helping to protect the lungs and maintain respiratory health.

4. What is the recommended daily fiber intake for adults?

A. 10 grams
B. 25 grams
C. 35 grams
D. 50 grams

Correct answer: B

Rationale: Rationale: The recommended daily fiber intake for adults is around 25 grams for women and 38 grams for men. Fiber is essential for maintaining a healthy digestive system, preventing constipation, and reducing the risk of chronic diseases such as heart disease and diabetes. Consuming an adequate amount of fiber can also help with weight management and promote overall well-being. Therefore, option B is the most appropriate answer based on the recommended daily intake guidelines for adults.

5. What is the main function of estuaries?

A. Filtering pollutants from water
B. Providing habitat for marine life
C. Storing carbon dioxide
D. Generating wind power

Correct answer: B

Rationale: Rationale: Estuaries are coastal areas where freshwater from rivers and streams mixes with saltwater from the ocean. They serve as important habitats for a variety of marine life, including fish, birds, and other wildlife. Estuaries provide shelter, breeding grounds, and food sources for many species, making them crucial for the overall health of marine ecosystems. While estuaries can help filter pollutants to some extent, their primary function is to support and sustain diverse populations of plants and animals. Storing carbon dioxide and generating wind power are not main functions of estuaries.