Nursing Elites

1. What is the phenomenon responsible for the mirage effect seen in deserts?

• A. Diffraction
• B. Refraction
• C. Interference
• D. Polarization

Correct answer: B

Rationale: Mirages occur due to the refraction of light by layers of air with different temperatures and densities, bending the light rays and creating the illusion of water on the horizon.

2. The fossil record shows that dinosaurs with feathers existed millions of years before birds. This is evidence for

• A. Convergent evolution (unrelated organisms evolving similar traits)
• B. Divergent evolution (related organisms evolving different traits)
• C. Coevolution (two species influencing each other's evolution)
• D. The extinction of dinosaurs due to an asteroid impact

Correct answer: A

Rationale: Rationale: The fossil record indicating that dinosaurs had feathers before birds suggests convergent evolution. Convergent evolution occurs when unrelated organisms independently evolve similar traits to adapt to similar environmental pressures. In this case, both dinosaurs and birds developed feathers for flight or insulation purposes, even though they are not closely related. This evidence supports the concept of convergent evolution rather than divergent evolution, coevolution, or the extinction of dinosaurs due to an asteroid impact.

3. A patient needs to take 2 tablets for every 30 pounds of body weight. If they weigh 150 pounds, how many tablets should they take?

• A. 5
• B. 10
• C. 15
• D. 20

Correct answer: A

Rationale: Divide the patient's weight (150 pounds) by the ratio denominator (30 pounds/tablet) to get 5 tablets.

4. Which of the following is responsible for generating the electrical impulses that regulate the heartbeat?

• A. Aorta
• B. Pulmonary veins
• C. Coronary arteries
• D. Sinoatrial (SA) node

Correct answer: D

Rationale: The correct answer is D: Sinoatrial (SA) node. The SA node, also known as the heart's natural pacemaker, is responsible for generating the electrical impulses that regulate the heartbeat. These impulses initiate each heartbeat by causing the atria to contract. The other options, Aorta, Pulmonary veins, and Coronary arteries, are important structures in the cardiovascular system but are not directly responsible for generating the electrical impulses that regulate the heartbeat.

5. The WBC (white blood cell) type responsible for the initial attack on pathogens is:

• A. Red blood cells
• B. Platelets
• C. Phagocytes
• D. Lymphocytes

Correct answer: C

Rationale: The correct answer is C: Phagocytes. Phagocytes are a type of white blood cell that plays a crucial role in the immune response by engulfing and destroying pathogens. They are the first line of defense against invading microorganisms, initiating the initial attack on pathogens. Red blood cells (option A) are responsible for carrying oxygen, not for immune responses. Platelets (option B) are involved in blood clotting. Lymphocytes (option D) are another type of white blood cell but are mainly responsible for specific immune responses rather than the initial attack on pathogens.

6. Which of the following is an example of stabilizing selection?

• A. Selection that favors extreme traits in a population
• B. Selection that removes individuals with extreme traits
• C. Selection that maintains the current average trait in a population
• D. Selection that favors one specific trait over all others

Correct answer: C

Rationale: Rationale: - Stabilizing selection is a type of natural selection that favors the intermediate variants in a population, while selecting against the extreme traits. This results in the maintenance of the current average trait in the population. - Option A is incorrect because stabilizing selection does not favor extreme traits; instead, it favors the average trait. - Option B is incorrect because stabilizing selection does not remove individuals with extreme traits; it acts against extreme traits by favoring the intermediate variants. - Option D is incorrect because stabilizing selection does not favor one specific trait over all others; it favors the average trait by selecting against extreme traits.

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