1. Which of the following is NOT a risk factor for developing atherosclerosis?

A. High blood pressure
B. High levels of LDL cholesterol
C. Regular physical activity
D. Smoking

Correct answer: C

Rationale: Regular physical activity is NOT a risk factor for developing atherosclerosis. In fact, engaging in regular physical activity can help reduce the risk of developing atherosclerosis by improving cardiovascular health, lowering blood pressure, and reducing LDL cholesterol levels. High blood pressure, high levels of LDL cholesterol, and smoking are all known risk factors for atherosclerosis. High blood pressure can damage blood vessels, making them more susceptible to plaque buildup. High levels of LDL cholesterol can lead to the accumulation of plaque in the arteries, narrowing the passageways and increasing the risk of atherosclerosis. Smoking is harmful to blood vessels, promoting inflammation and the formation of plaque. Therefore, regular physical activity is actually a protective factor against atherosclerosis rather than a risk factor.

2. What is the main function of dietary fiber in the digestive system?

A. To provide energy
B. To break down fats
C. To promote gut bacteria growth
D. To aid in absorption of nutrients

Correct answer: C

Rationale: Rationale: Dietary fiber refers to the indigestible portion of plant foods that passes relatively intact through the digestive system. While fiber does not provide energy directly to the body, it plays a crucial role in promoting the growth of beneficial gut bacteria. These bacteria help in the fermentation of fiber, producing short-chain fatty acids that can be used as an energy source by the body. Additionally, fiber helps regulate bowel movements, maintain gut health, and support overall digestive function. Therefore, the main function of dietary fiber in the digestive system is to promote gut bacteria growth.

3. What is the role of surfactant in the respiratory system?

A. To trap dust particles
B. To increase lung compliance
C. To produce mucus
D. To generate oxygen during respiration

Correct answer: B

Rationale: The correct answer is B: 'To increase lung compliance.' Surfactant is a substance produced by the alveolar cells in the lungs that reduces surface tension within the alveoli. This helps to prevent the alveoli from collapsing, making it easier for the lungs to expand and contract during breathing. This action increases lung compliance, which is the ease with which the lungs can be inflated. Trapping dust particles (A) is the role of mucus and cilia in the respiratory system. Surfactant does not produce mucus (C) but rather acts to reduce surface tension. Generating oxygen (D) is the function of the respiratory system as a whole through the process of respiration, and surfactant does not play a direct role in this process.

4. During normal breathing, which muscle is the primary driver of inhalation by contracting and flattening to increase the volume of the thoracic cavity?

A. Diaphragm
B. Intercostal muscles
C. Abdominal muscles
D. Pectoral muscles

Correct answer: A

Rationale: The diaphragm is the primary muscle responsible for inhalation during normal breathing. When the diaphragm contracts and flattens, it increases the volume of the thoracic cavity, creating a negative pressure that allows air to rush into the lungs. The intercostal muscles also play a role in expanding the ribcage to assist with inhalation. However, the diaphragm is the main driver of the breathing process by creating the necessary space for the lungs to expand and fill with air.

5. A pizza has a diameter of 40cm. What is its perimeter (circumference)?

A. 62.8cm
B. 125.5cm
C. 125.6cm
D. 251.2cm

Correct answer: C

Rationale: Multiply the diameter by Ï€: perimeter = Ï€ * diameter = Ï€ * 40cm â‰ˆ 125.6cm (Note: Ï€ â‰ˆ 3.14)

6. What is the primary function of the epiglottis in the respiratory system?

A. Filtration of air
B. Production of mucus
C. Prevention of food entering the trachea
D. Oxygen exchange in the alveoli

Correct answer: C

Rationale: The primary function of the epiglottis in the respiratory system is to prevent food from entering the trachea. When we swallow, the epiglottis covers the opening to the trachea, directing food and liquids to the esophagus instead of the airway. This action helps to protect the respiratory system from foreign objects that could obstruct airflow and cause choking or aspiration pneumonia. Filtration of air and production of mucus are functions associated with other respiratory structures like the nasal passages and bronchial tubes, while oxygen exchange in the alveoli occurs in the lungs, not the epiglottis.