Nursing Elites

1. What are the fundamental units of structure and function in all living organisms, including humans, termed?

• A. Muscles
• B. Organs
• C. Tissues
• D. Cells

Correct answer: D

Rationale: Cells are the fundamental units of structure and function in all living organisms. They are the basic building blocks of life and carry out essential functions necessary for an organism to survive and function properly. Muscles, organs, and tissues are composed of cells, but cells are the smallest unit that can carry out all the functions of life. Muscles are made up of muscle tissue, which in turn is composed of muscle cells. Organs are structures made up of different types of tissues working together, and tissues are groups of cells with a similar structure and function. Therefore, while muscles, organs, and tissues are important components of living organisms, cells are the fundamental units that perform all the vital functions of life.

2. Positron emission tomography (PET) scans utilize a key property of positrons for medical imaging. What is this property?

• A. High mass
• B. Positive charge
• C. Extreme stability
• D. Identical behavior to electrons

Correct answer: B

Rationale: Positron emission tomography (PET) scans utilize the property of positrons having a positive charge. Positrons are the antimatter counterpart of electrons, having the same mass but opposite charge. When a positron collides with an electron, they annihilate each other, producing gamma rays that can be detected by the PET scanner to create images of the body's internal structures and functions. Choice A is incorrect because positrons have the same mass as electrons. Choice C is incorrect as positrons are not extremely stable due to their tendency to annihilate when they encounter electrons. Choice D is incorrect as positrons exhibit different behavior than electrons due to their opposite charges.

3. Which of the following is NOT a property of a catalyst?

• A. Increases the rate of a reaction
• B. Remains unchanged after the reaction
• C. Lowers the activation energy
• D. Creates new products

Correct answer: D

Rationale: A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process. It remains unchanged after the reaction, which eliminates option B. A catalyst works by lowering the activation energy required for the reaction to occur, which eliminates option C. A catalyst does not create new products in a reaction; it only facilitates the conversion of reactants into products more efficiently. Therefore, option D is NOT a property of a catalyst.

4. What causes varicose veins to occur?

• A. Atherosclerosis.
• B. Incompetent valves.
• C. Loss of skin turgor.
• D. Loss of blood vessel elasticity.

Correct answer: B

Rationale: Varicose veins occur when the valves within the veins become incompetent, leading to blood pooling in the veins instead of being efficiently pumped back to the heart. This causes the veins to become enlarged, twisted, and visible under the skin. Factors such as genetics, aging, pregnancy, and prolonged standing or sitting can contribute to the development of incompetent valves and the resulting varicose veins. Atherosclerosis is the buildup of plaque in arteries, not veins, and does not directly cause varicose veins. Loss of skin turgor is related to skin elasticity and not a direct cause of varicose veins. Loss of blood vessel elasticity is a general term and does not specifically address the mechanism behind varicose veins, which is primarily due to incompetent valves.

5. Which of the following molecules is a monosaccharide?

• A. Starch
• B. Glucose
• C. Cellulose
• D. Sucrose

Correct answer: B

Rationale: Starch is a polysaccharide, not a monosaccharide, making choice A incorrect. Glucose, choice B, is the correct answer as it is a monosaccharide, the simplest form of sugar. Cellulose, choice C, is a polysaccharide like starch, not a monosaccharide. Sucrose, choice D, is a disaccharide composed of glucose and fructose, not a monosaccharide. Glucose, being a monosaccharide, is a single sugar unit that serves as a primary energy source for living organisms.

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