1. Bradycardia refers to a heart rate that is:

A. Normal (60-100 bpm)
B. Slightly elevated (100-120 bpm)
C. Significantly elevated (>120 bpm)
D. Abnormally slow (<60 bpm)

Correct answer: D

Rationale: The correct answer is D. Bradycardia refers to an abnormally slow heart rate, typically defined as being less than 60 beats per minute (bpm). A heart rate of 60-100 bpm is considered normal, not bradycardia. Choices B and C incorrectly describe elevated heart rates, which are not characteristic of bradycardia. Therefore, option D is the most accurate description of bradycardia as it signifies a heart rate that is slower than normal.

2. Which phrase best describes the tone of the passage?

A. Humorous and lighthearted
B. Suspenseful and mysterious
C. Objective and informative
D. Critical and judgmental

Correct answer: C

Rationale: The passage presents factual information without injecting personal opinions or emotions. A, B, and D suggest tones not present in the passage's neutral delivery.

3. The phrase "disruptions to ecosystems" refers to

A. Minor inconveniences experienced by plant and animal species due to changing weather patterns.
B. Significant changes in ecological relationships and imbalances in populations and food webs.
C. The aesthetic alteration of landscapes due to melting glaciers and deforestation.
D. The economic losses suffered by industries relying on natural resources affected by climate change.

Correct answer: B

Rationale: The phrase suggests profound impacts on ecological balance and species interactions, aligning with B.

4. The process by which a solid changes directly into a liquid is called:

A. Melting
B. Condensation
C. Sublimation
D. Deposition

Correct answer: D

Rationale: While melting is a solid to liquid transition, deposition, also known as sublimation, refers to a gas directly changing into a solid.

5. Testosterone is a crucial hormone in the male reproductive system. What is its primary function?

A. Egg production
B. Sperm production and development
C. Regulation of the menstrual cycle
D. Milk production

Correct answer: B

Rationale: The correct answer is B: Sperm production and development. Testosterone is a hormone primarily produced in the testes and is essential for the development of male reproductive tissues, including the testes and prostate. It plays a key role in the production of sperm cells (spermatogenesis) and the development of secondary sexual characteristics in males, such as facial hair and muscle mass. Testosterone is not involved in egg production (A), regulation of the menstrual cycle (C), or milk production (D) as these are functions associated with female reproductive hormones.