1. Which organelle is responsible for cellular respiration, producing ATP for energy?

A. Nucleus
B. Mitochondria
C. Golgi apparatus
D. Vacuole

Correct answer: B

Rationale: The correct answer is B: Mitochondria. Mitochondria are known as the powerhouse of the cell because they are responsible for cellular respiration, a process that produces ATP (adenosine triphosphate) for energy. The other organelles listed, such as the nucleus, Golgi apparatus, and vacuole, do not play a direct role in cellular respiration or ATP production. The mitochondria contain specialized structures like cristae and enzymes that carry out the biochemical reactions of cellular respiration, making them essential for energy production in the cell.

2. Which of the following is an example of static friction?

A. Sliding a heavy box across the floor
B. A car moving around a curve
C. Pushing a stationary object
D. Braking a car to stop

Correct answer: c

Rationale: Static friction occurs when an object is at rest and prevents it from moving when a force is applied.

3. The professor explained the concept clearly. What is the past participle of the verb "explain"?

A. explains
B. explaining
C. explained
D. explanation

Correct answer: C

Rationale: The past participle is used to form verb tenses and passive voice constructions.

4. The small intestine is where most of the chemical digestion and nutrient absorption occur. What is the finger-like projection in the small intestine that increases its surface area for absorption?

A. Rugae
B. Villi
C. Microvilli
D. All of the above

Correct answer: D

Rationale: The correct answer is D, 'All of the above.' The finger-like projection in the small intestine that increases its surface area for absorption is primarily the villi and microvilli. Villi are small, finger-like projections that line the inner wall of the small intestine, while microvilli are even smaller projections on the surface of the villi. Both structures significantly increase the surface area of the small intestine, allowing for more efficient absorption of nutrients. Rugae, on the other hand, are folds in the stomach lining that help with expansion when the stomach is full. Therefore, the rugae are not directly related to the increased surface area for absorption in the small intestine, making options A and B incorrect choices. Overall, options A, B, and C are all related to the structure of the small intestine but serve different functions, so the most appropriate answer is D, 'All of the above.'

5. Photons, the basic unit of light, are:

A. Charged particles
B. Packets of energy with wave-particle duality
C. Electromagnetic waves only
D. Always absorbed by matter

Correct answer: B

Rationale: The correct answer is B: Packets of energy with wave-particle duality. Photons are the smallest discrete amount of electromagnetic radiation and exhibit both wave-like and particle-like properties. While photons do not have a charge, they do carry energy and momentum. This dual nature of photons is a fundamental concept in quantum mechanics. Photons can travel as both waves and particles, and their behavior is described by the wave-particle duality principle. Therefore, option B accurately describes the nature of photons as packets of energy with wave-particle duality.