1. A new material is claimed to be stronger than steel. You design an experiment to test this claim. What is the MOST important control variable?

A. The size of the material samples.
B. The temperature at which the test is conducted.
C. The force applied to the material.
D. The color of the material.

Correct answer: A

Rationale: The size of the material samples is the most important control variable because it ensures that the comparison between the new material and steel is fair and accurate. By keeping the size consistent, any differences in strength can be attributed to the material composition rather than variations in sample size. Controlling for size helps eliminate confounding variables and increases the reliability of the experiment results. Temperature, force applied, and color are not as critical for directly testing the strength comparison between the new material and steel.

2. Ms. Valencia is responsible to the number of personnel reporting to her. This principle refers

A. Span of control
B. Unity of command
C. Carrot and stick principle
D. Esprit dâ€™ corp

Correct answer: B

Rationale: The correct answer is B: Unity of command. Unity of command is a fundamental principle of management stating that each employee should receive orders from only one supervisor to avoid confusion and ensure clarity in the chain of command. In this scenario, Ms. Valencia's responsibility for the number of personnel reporting to her aligns with the concept of unity of command. Span of control refers to the number of subordinates a supervisor can efficiently manage, while the carrot and stick principle involves motivating employees through rewards and punishments. Esprit dâ€™ corp refers to the sense of unity and camaraderie within a group.

3. Which hormone primarily triggers ovulation in the female menstrual cycle?

A. Estrogen
B. Progesterone
C. Luteinizing hormone (LH)
D. Follicle-stimulating hormone (FSH)

Correct answer: C

Rationale: The correct answer is C: Luteinizing hormone (LH). LH is the hormone responsible for triggering ovulation in the female menstrual cycle. During the menstrual cycle, LH surge occurs around day 14, which stimulates the release of a mature egg from the ovary. This surge in LH is crucial for the rupture of the mature follicle and the release of the egg, marking the onset of ovulation. Estrogen and progesterone play important roles in regulating the menstrual cycle, but LH specifically triggers ovulation by signaling the release of the egg from the ovary.

4. Which of the following is the best approach to resolving conflicting scientific findings?

A. Dismiss one set of findings as wrong without further investigation.
B. Conduct additional research to identify potential sources of discrepancies.
C. Accept the findings from the more prestigious research institution.
D. Rely on media interpretations and public opinion to settle the debate.

Correct answer: B

Rationale: When faced with conflicting scientific findings, the best approach is to conduct additional research to identify potential sources of discrepancies. This allows for a more thorough understanding of the topic and helps in resolving the conflicting findings through a scientific and evidence-based approach. Dismissing findings without further investigation, relying on prestige, or turning to media interpretations and public opinion can lead to misunderstandings and hinder scientific progress. Conducting additional research promotes a more comprehensive and accurate understanding of the subject matter.

5. What is the main topic of the passage?

A. Benefits of bioremediation in cleaning oil spills.
B. Dangers of microplastics to marine ecosystems.
C. History of plastic production and its global impact.
D. Comparison of different waste management strategies.

Correct answer: B

Rationale: The passage focuses on the specific issue of microplastics in the marine environment and their harmful effects.

6. The T wave on an ECG corresponds to:

A. Atrial depolarization
B. Ventricular depolarization
C. Atrial repolarization
D. Ventricular repolarization

Correct answer: D

Rationale: The T wave on an ECG corresponds to ventricular repolarization. During this phase, the ventricles are resetting electrically after contraction, preparing for the next heartbeat. Atrial depolarization is represented by the P wave, ventricular depolarization by the QRS complex, and atrial repolarization is typically hidden within the QRS complex. Therefore, option D, 'Ventricular repolarization,' is the correct choice when identifying the electrical activity represented by the T wave on an ECG.