Nursing Elites

1. What is the difference between DNA and RNA?

• A. Both are double-stranded.
• B. DNA contains deoxyribose sugar, while RNA contains ribose sugar.
• C. RNA contains the nitrogenous base uracil, while DNA contains thymine.
• D. Both are identical molecules.

Correct answer: B

Rationale: Rationale: A) Incorrect. DNA is double-stranded, but RNA is typically single-stranded. B) Correct. DNA contains deoxyribose sugar, which lacks an oxygen atom on the 2' carbon of the sugar ring, while RNA contains ribose sugar, which has an additional hydroxyl group on the 2' carbon. C) Incorrect. RNA contains the nitrogenous base uracil, while DNA contains thymine. D) Incorrect. DNA and RNA have distinct structures and functions, so they are not identical molecules.

2. Which property of a substance refers to the force exerted on an object due to gravity?

• A. Mass
• B. Weight
• C. Density
• D. Volume

Correct answer:

Rationale: Weight is the measure of the force exerted on an object due to gravity. It is calculated as mass multiplied by the acceleration due to gravity.

3. Saliva contains an enzyme that breaks down carbohydrates. What is the name of this enzyme?

• A. Pepsin
• B. Amylase
• C. Lipase
• D. Trypsin

Correct answer: B

Rationale: The correct answer is B: Amylase. Saliva contains the enzyme amylase, which is responsible for breaking down carbohydrates into simpler sugars like maltose and glucose. Pepsin (A) is an enzyme found in the stomach that breaks down proteins. Lipase (C) is an enzyme that breaks down fats, and trypsin (D) is another enzyme that breaks down proteins, but both of these are not found in saliva. Knowing the function of amylase in saliva helps in the digestion of carbohydrates, making it the correct answer.

4. What is the formula for calculating molarity?

• A. M = n/V
• B. M = n/L
• C. M = mol/L
• D. M = mol/dm³

Correct answer: a

Rationale: All of these choices are equivalent to the original formula. The symbol "n" represents the number of moles of solute, and the symbol "V" represents the volume of the solution in liters. The symbol "L" is an abbreviation for "liters," and "dm³" is an alternative way to represent liters.

5. A satellite orbits the Earth at constant speed. Which force is responsible for its circular motion?

• A. Gravitational force from the Earth
• B. Thrust from the satellite's engine
• C. Friction between the satellite and the atmosphere
• D. Normal force from the Earth's surface

Correct answer: A

Rationale: This force acts towards the Earth's center, providing the centripetal force required for the satellite to move in a circle.

6. The term that refers to the specific role and position an organism occupies within an ecosystem is called a:

• A. Habitat
• B. Niche
• C. Population
• D. Biome

Correct answer: B

Rationale: Rationale: A) Habitat refers to the specific physical environment where an organism lives, including the biotic and abiotic factors present. While the habitat is important for an organism's survival, it does not encompass the specific role and interactions of the organism within the ecosystem. B) Niche refers to the specific role and position an organism occupies within an ecosystem, including its interactions with other organisms and its physical environment. This includes the organism's feeding habits, behavior, preferred habitat, and how it obtains resources. The niche of an organism is crucial in determining its impact on the ecosystem and its relationships with other species. C) Population refers to a group of individuals of the same species living in a specific area and interacting with each other. While populations play a role in ecosystems, they do not specifically describe the role and position of an individual organism within the ecosystem. D) Biome refers to a large geog

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