Nursing Elites

1. 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.

2. What is an isotope? For any given element, it is an atom with which of the following?

• A. a different atomic number
• B. a different number of protons
• C. a different number of electrons
• D. a different mass number

Correct answer: D

Rationale: An isotope of an element is an atom with a different number of neutrons, resulting in a different mass number. Isotopes of the same element have the same number of protons (which determines the element's identity) but differ in the number of neutrons, leading to variations in mass numbers. Choice A is incorrect because isotopes of the same element have the same atomic number. Choice B is incorrect because isotopes of the same element have the same number of protons. Choice C is incorrect because isotopes of the same element have the same number of electrons.

3. Which of the following substances is NOT a product of cellular respiration?

• A. Carbon dioxide
• B. Water
• C. Oxygen
• D. ATP

Correct answer: C

Rationale: The correct answer is C. Oxygen is not a product of cellular respiration; instead, it is consumed during the process. During cellular respiration, glucose is broken down in the presence of oxygen to produce energy in the form of ATP, carbon dioxide, and water. Carbon dioxide is released as a waste product, water is a byproduct of the chemical reactions, and ATP is the energy currency used by cells. Therefore, options A, B, and D are all products or outcomes of cellular respiration, while oxygen is a reactant.

4. Which of the following processes describes the conversion of glucose to pyruvic acid during glycolysis?

• A. Glycogenesis
• B. Glycolysis
• C. Glycogenolysis
• D. Gluconeogenesis

Correct answer: B

Rationale: The correct answer is B: Glycolysis. Glycolysis is the metabolic pathway where glucose is broken down to produce pyruvic acid and ATP, generating energy in the form of ATP. Glycogenesis (choice A) is the process of glycogen synthesis, Glycogenolysis (choice C) is the breakdown of glycogen to release glucose, and Gluconeogenesis (choice D) is the synthesis of glucose from non-carbohydrate sources. Therefore, during glycolysis, glucose is converted into pyruvic acid, which is a crucial step in energy production.

5. What is the rigid structure that provides shape and support to plant cells?

• A. Cell wall
• B. Plasma membrane
• C. Nucleus
• D. Cytoplasm

Correct answer: A

Rationale: The correct answer is the cell wall, as it is the rigid structure that provides shape and support to plant cells. The cell wall is located outside the plasma membrane and is primarily composed of cellulose, giving it its rigid nature. The plasma membrane (option B) is a semi-permeable membrane surrounding the cell that regulates the movement of substances in and out of the cell. The nucleus (option C) houses the cell's genetic material and controls cellular activities. Cytoplasm (option D) is the gel-like substance within the cell that surrounds organelles and where various cellular processes take place, but it does not provide the rigid structure and support that the cell wall does.

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