1. The microscopic units responsible for muscle contraction are called

A. Neurons
B. Myofibrils
C. Tendons
D. Sarcomeres

Correct answer: D

Rationale: The correct answer is D: Sarcomeres. Sarcomeres are the fundamental contractile units of skeletal muscle. They are composed of overlapping actin and myosin filaments that slide past each other during muscle contraction, resulting in muscle shortening. Neurons (A) are nerve cells that transmit signals to and from the brain. Myofibrils (B) are thread-like structures within muscle fibers that contain sarcomeres. Tendons (C) are fibrous connective tissues that attach muscles to bones, but they are not directly involved in muscle contraction like sarcomeres are.

2. What happens to the concentration of hydrogen ions ($[H^+]$) in a solution as the pH increases?

A. Increases
B. Decreases
C. Remains constant
D. Becomes neutral

Correct answer: B

Rationale: As the pH increases, the concentration of hydrogen ions decreases. The relationship is inversely proportional

3. Julius plans to revisit the organizational chart of the department. He plans to create a new

A. Box
B. Solid line
C. Broken line
D. Dotted line

Correct answer: B

Rationale: The correct answer is B: 'Solid line.' In organizational charts, solid lines typically represent formal reporting relationships, indicating direct authority and responsibility between positions. Creating a new solid line on the chart would signify a new formal reporting relationship within the department. This can be important for clarifying roles, communication channels, and decision-making processes. Boxes represent positions or roles in the organizational structure, while broken lines and dotted lines are typically used for informal relationships or advisory roles, rather than formal reporting relationships.

4. What is the medical term for heartburn, a burning sensation in the chest caused by stomach acid?

A. Dysphagia
B. Gastroesophageal reflux disease (GERD)
C. Peptic ulcer
D. Ulcerative colitis

Correct answer: B

Rationale: Rationale: A) Dysphagia refers to difficulty swallowing and is not specifically related to heartburn. B) Gastroesophageal reflux disease (GERD) is the medical term for heartburn, which is a burning sensation in the chest caused by stomach acid flowing back up into the esophagus. C) Peptic ulcer is a sore that develops on the lining of the stomach, small intestine, or esophagus, and it can cause symptoms such as abdominal pain, not specifically heartburn. D) Ulcerative colitis is a type of inflammatory bowel disease that affects the colon and rectum, and it does not typically cause heartburn.

5. What is the main difference between a telescope and a microscope?

A. Telescopes magnify distant objects, while microscopes magnify small objects.
B. Telescopes use lenses, while microscopes use mirrors.
C. Telescopes collect light, while microscopes emit light.
D. They both magnify objects but serve different purposes.

Correct answer: A

Rationale: While both instruments magnify objects, telescopes are designed to observe distant objects, while microscopes are used to magnify tiny objects close to the observer.