1. 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.

2. What is the main purpose of biological classification?

A. To create a rigid and unchanging system for labeling organisms
B. To understand the diversity and interconnectedness of life
C. To simplify nature into neat and tidy categories
D. To assign organisms to specific ecological niches

Correct answer: B

Rationale: Rationale: Biological classification, also known as taxonomy, is the science of categorizing and organizing living organisms based on shared characteristics. The main purpose of biological classification is not to create a rigid and unchanging system (option A) or to simplify nature into neat and tidy categories (option C). Instead, it aims to help us understand the diversity of life on Earth and how different organisms are related to each other. By classifying organisms into groups based on their evolutionary relationships, we can gain insights into the interconnectedness of life and better appreciate the complexity and beauty of the natural world. Assigning organisms to specific ecological niches (option D) is more related to ecological studies rather than biological classification.

3. Which property of a wave remains constant when the wave enters a different medium?

A. Frequency
B. Wavelength
C. Amplitude
D. Speed

Correct answer: d

Rationale: The speed of a wave remains constant when it enters a different medium, provided the conditions are unchanged.

4. Which of the following is an example of a decomposition reaction?

A. 2H2 + O2 â†’ 2H2O
B. CaCO3 â†’ CaO + CO2
C. 2Na + Cl2 â†’ 2NaCl
D. N2 + 3H2 â†’ 2NH3

Correct answer: b

Rationale: Decomposition reactions involve the breakdown of a compound into simpler substances.

5. Inhalation

A. Expiration
B. Respiration
C. Aspiration
D. Aspiration

Correct answer: B

Rationale: The correct answer is B: 'Respiration.' Inhalation refers to the process of breathing in air, while respiration is the overall process of gas exchange in the body, including both inhalation and exhalation. Expiration refers specifically to the process of breathing out air. Aspiration, on the other hand, refers to the act of inhaling foreign objects into the lungs, which can be harmful. Therefore, 'Respiration' is the most appropriate term related to 'Inhalation' as it encompasses the entire process of breathing and gas exchange in the body.

6. What is the significance of cell division?

A. Growth and repair of tissues
B. Sexual reproduction
C. Genetic diversity
D. All of the above

Correct answer: D

Rationale: Cell division is a fundamental process that is essential for the growth, repair, and reproduction of all living organisms. It plays a crucial role in ensuring that organisms maintain their proper size and shape, and it allows for the replacement of damaged or worn-out cells. Cell division is also essential for sexual reproduction, as it is the process by which haploid gametes (sex cells) are produced. These gametes fuse during fertilization to form a diploid zygote, which ultimately gives rise to a new organism.