Nursing Elites

1. Which of the following is the positively charged subatomic particle found in the nucleus of an atom?

• A. Electron
• B. Proton
• C. Neutron
• D. Quark

Correct answer: B

Rationale: The correct answer is B: Proton. Protons are positively charged subatomic particles found in the nucleus of an atom. They have a mass of approximately 1 atomic mass unit (amu) and a charge of +1. The number of protons in an atom's nucleus determines the atomic number of the element, which is a unique identifier for each element. Choice A, Electron, is incorrect as electrons are negatively charged particles found outside the nucleus. Choice C, Neutron, is incorrect as neutrons are neutral particles found in the nucleus. Choice D, Quark, is incorrect as quarks are elementary particles that combine to form protons and neutrons, but they are not the positively charged particle found in the nucleus of an atom.

2. Which of the following best describes a balanced force acting on an object?

• A. The object remains at rest
• B. The object moves with constant velocity
• C. The object accelerates
• D. The object's mass changes

Correct answer: B

Rationale: When a balanced force acts on an object, the net force is zero, resulting in no acceleration. This means that the object will continue to move with a constant velocity if it was already in motion or remain at rest if it was initially stationary. Choice A is incorrect because the object can also move with constant velocity. Choice C is incorrect as acceleration only occurs when an unbalanced force is applied. Choice D is incorrect as the mass of an object is not affected by the balance of forces acting on it.

3. What is one feature that both prokaryotes and eukaryotes have in common?

• A. A plasma membrane
• B. A nucleus enclosed by a membrane
• C. Organelles
• D. A nucleoid

Correct answer: A

Rationale: The correct answer is A: A plasma membrane. Both prokaryotes and eukaryotes share the characteristic of having a plasma membrane that surrounds the cell. While eukaryotes also possess a nucleus enclosed by a membrane and various organelles, prokaryotes lack a nucleus and membrane-bound organelles. The plasma membrane, however, is a universal feature found in all cells, regardless of their classification as prokaryotic or eukaryotic. Choice B is incorrect because only eukaryotes have a nucleus enclosed by a membrane. Choice C is incorrect because prokaryotes have limited organelles compared to eukaryotes. Choice D is incorrect as a nucleoid is a region in prokaryotic cells where the genetic material is located, not a common feature shared with eukaryotes.

4. Which valve prevents backflow into the atrium when the ventricles contract?

• A. Pulmonary valve
• B. Tricuspid valve
• C. Mitral valve
• D. Aortic valve

Correct answer: B

Rationale: The tricuspid valve (right atrioventricular valve) prevents backflow into the right atrium when the right ventricle contracts. This valve ensures that blood flows in the correct direction, preventing regurgitation into the atrium. The pulmonary valve is responsible for preventing backflow into the right ventricle from the pulmonary artery. The mitral valve prevents backflow into the left atrium, and the aortic valve prevents backflow into the left ventricle from the aorta. Therefore, the correct answer is the tricuspid valve as it specifically addresses the scenario of backflow into the atrium during ventricular contraction.

5. Which radioactive isotope is commonly used in medical imaging techniques such as PET scans?

• A. Uranium-235
• B. Plutonium-239
• C. Potassium-40
• D. Fluorine-18

Correct answer: D

Rationale: Fluorine-18 is the radioactive isotope commonly used in medical imaging techniques such as PET scans. It is frequently used in the form of fluorodeoxyglucose (FDG) to locate areas of heightened metabolic activity in the body, such as in cancer cells. Uranium-235 and Plutonium-239 are not typically employed in medical imaging, and Potassium-40, while a naturally occurring radioactive isotope found in the human body, is not commonly used in medical imaging techniques.

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