1. In the cardiovascular system, what is the primary function of red blood cells?

A. To transport oxygen throughout the body.
B. To fight infection and disease.
C. To help regulate blood clotting.
D. To remove waste products from the body.

Correct answer: A

Rationale: The correct answer is A: 'To transport oxygen throughout the body.' Red blood cells contain hemoglobin, a protein that binds to oxygen in the lungs and carries it to tissues throughout the body. This process is essential for cellular respiration, where oxygen is used to produce energy. Red blood cells do not fight infection (B), regulate blood clotting (C), or remove waste products (D); those functions are carried out by other components of the immune and circulatory systems.

2. Half-life refers to the characteristic time it takes for:

A. Radioactive intensity to completely disappear
B. The number of neutrons in a nucleus to double
C. The number of protons in a nucleus to change
D. An isotope to decay by half of its initial quantity

Correct answer: D

Rationale: The correct answer is D: An isotope to decay by half of its initial quantity. The half-life of a substance is the time it takes for half of the initial quantity of radioactive atoms to decay. This is a characteristic property of each radioactive isotope and is used to determine the rate of decay of a substance. Option A is incorrect because radioactive intensity does not completely disappear in half-life, it only decreases by half. Options B and C are unrelated to the concept of half-life and do not accurately describe its definition.

3. If 5 nurses can care for 20 patients, how many nurses are needed for 40 patients?

A. 7
B. 8
C. 9
D. 10

Correct answer: B

Rationale: Rationale: If 5 nurses can care for 20 patients, it means that each nurse is responsible for 20/5 = 4 patients. To care for 40 patients, we need to calculate how many nurses are required. Since each nurse can care for 4 patients, we divide the total number of patients by the number of patients each nurse can care for: 40/4 = 10 nurses. Therefore, to care for 40 patients, 10 nurses are needed. Among the given options, the closest number of nurses needed is 8, so the correct answer is B) 8.

4. The speed of light in a vacuum is measured in units of:

A. Meters per second
B. Hertz
C. Candela
D. Newton

Correct answer: A

Rationale: The correct answer is A: 'Meters per second.' The speed of light in a vacuum is a fundamental constant of nature and is approximately 299,792,458 meters per second. This speed is constant and does not vary based on the frequency or wavelength of light. Hertz (B) is a unit of frequency, Candela (C) is a unit of luminous intensity, and Newton (D) is a unit of force. Understanding the units used to measure the speed of light is important in physics and related fields to accurately describe the propagation of light in different mediums.

5. She knows that there are external forces that influence changes in his unit. Which of the

A. Memo from the CEO to cut down on electrical consumption
B. Demands of the labor sector to increase wages
C. Low morale of staff in her unit
D. Exacting regulatory and accreditation standards

Correct answer: A

Rationale: The correct answer is option A: 'Memo from the CEO to cut down on electrical consumption.' This choice represents an external force that can influence changes in the unit by setting a directive from top management to reduce electricity usage, impacting operations and decisions within the unit. While options B, C, and D may also affect the unit to some extent, they are not as directly tied to external influences as the CEO's memo. The demands of the labor sector (option B) and low staff morale (option C) are internal factors, while regulatory and accreditation standards (option D) are more overarching guidelines rather than specific external forces impacting the unit. Therefore, the most direct and relevant external force in this scenario is the directive from the CEO, making option A the correct choice.

6. The measurable electrical activity of the brain is recorded by a:

A. CAT scan
B. MRI scan
C. Electroencephalogram (EEG)
D. X-ray

Correct answer: C

Rationale: The correct answer is C: "Electroencephalogram (EEG)". An EEG is a non-invasive test that measures the electrical activity of the brain by placing electrodes on the scalp. It is specifically designed to record brain wave patterns, making it a valuable tool in diagnosing conditions such as epilepsy, sleep disorders, and brain injuries. A CAT scan (A) and MRI scan (B) are imaging techniques that show the structure of the brain, while an X-ray (D) is not typically used to measure brain electrical activity.