Nursing Elites

1. Which organelle is responsible for producing energy in the cell?

• A. Nucleus
• B. Mitochondria
• C. Golgi apparatus
• D. Ribosome

Correct answer: B

Rationale: The correct answer is B: Mitochondria. Mitochondria are known as the powerhouse of the cell and are responsible for producing energy in the form of ATP through the process of cellular respiration. The other organelles listed, such as the nucleus, Golgi apparatus, and ribosome, have different functions within the cell and are not directly involved in energy production. The nucleus is responsible for storing genetic material and controlling cell activities. The Golgi apparatus is involved in modifying, sorting, and packaging proteins. Ribosomes are responsible for protein synthesis.

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: B

Rationale: The correct answer is 'Weight.' Weight is the force exerted on an object due to gravity. Mass, on the other hand, refers to the amount of matter in an object. Density is the mass per unit volume of a substance, and volume is the amount of space occupied by an object. In this context, weight specifically relates to the gravitational force acting on an object, making it the most appropriate choice among the options provided.

3. What is the role of RNA in protein synthesis?

• A. Stores genetic information
• B. Decodes genetic information
• C. Provides energy for the process
• D. Transports amino acids to the ribosomes

Correct answer: B

Rationale: RNA plays a crucial role in protein synthesis by decoding the genetic information stored in DNA and carrying it to the ribosomes where proteins are synthesized. This process involves transcription, where RNA is synthesized from DNA, and translation, where the information in RNA is used to assemble amino acids into proteins. RNA acts as a messenger between DNA and the ribosomes, ensuring that the correct sequence of amino acids is used to build proteins according to the genetic code. Option A is incorrect because DNA, not RNA, stores genetic information. Option C is incorrect because RNA does not provide energy for protein synthesis; energy is usually provided by ATP molecules. Option D is incorrect because tRNA (transfer RNA) is responsible for transporting amino acids to the ribosomes, not RNA in general. Therefore, option B is the most appropriate choice as it accurately describes the role of RNA in protein synthesis.

4. What effect does a catalyst have on a chemical reaction?

• A. It speeds up the reaction.
• B. It slows down the reaction.
• C. It makes a reaction go in reverse.
• D. It prevents a reaction from taking place.

Correct answer: A

Rationale: A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process. It works by providing an alternate pathway for the reaction to occur, lowering the activation energy needed for the reaction to proceed. As a result, more reactant molecules can overcome this energy barrier and participate in the reaction, leading to a faster overall reaction rate. This explanation contradicts choices B, C, and D as a catalyst does not slow down, reverse, or prevent a reaction; instead, it accelerates the reaction by facilitating a more efficient route for the reaction to take place. Therefore, the correct answer is that a catalyst speeds up the reaction.

5. What property of a substance refers to its ability to undergo a chemical change and form new substances with different properties?

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

Correct answer: C

Rationale: Reactivity is the property of a substance that describes its ability to undergo a chemical change and form new substances with different properties. Density (A), mass (B), and volume (D) are physical properties of a substance and do not directly relate to its ability to undergo chemical changes. Density is mass per unit volume, mass is the amount of matter in a substance, and volume is the space occupied by a substance.

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