Nursing Elites

1. Which nitrogenous bases pair with each other in DNA?

• A. A-G and T-C
• B. A-T and C-G
• C. A-T and T-T
• D. C-C and G-G

Correct answer: B

Rationale: In DNA, nitrogenous bases pair with each other in a specific manner known as complementary base pairing. Adenine (A) always pairs with Thymine (T), and Cytosine (C) always pairs with Guanine (G). This pairing is essential for maintaining the structure and function of DNA. Option B is the correct answer as it correctly identifies the nitrogenous bases that pair with each other in DNA. Choices A, C, and D are incorrect because they do not follow the established base pairing rules in DNA. A-T and C-G are the complementary base pairs in DNA, ensuring the stability and replication fidelity of the genetic material.

2. What is the primary function of the heart?

• A. Filtering blood
• B. Exchanging gases
• C. Pumping blood throughout the body
• D. Producing hormones

Correct answer: C

Rationale: The main function of the heart is to pump blood throughout the body. The heart acts as a muscular pump that circulates blood, delivering oxygen and nutrients to the body's tissues and removing waste products. Option A is incorrect because blood filtration is a function of the kidneys, not the heart. Option B is incorrect as gas exchange occurs in the lungs, not the heart. Option D is also incorrect as hormone production is mainly carried out by endocrine glands, not the heart.

3. What is the name of the curved bone in the back that provides support and attachment for muscles?

• A. Sternum
• B. Scapula
• C. Clavicle
• D. Vertebral column

Correct answer: D

Rationale: The vertebral column, also known as the spine, is the curved bone in the back that provides support and attachment for muscles. It consists of individual vertebrae stacked on top of each other, forming a flexible and protective structure for the spinal cord. The sternum, scapula, and clavicle are bones in the chest and shoulder regions, not in the back where the vertebral column is located. Therefore, the correct answer is the vertebral column (Option D). Options A, B, and C are incorrect as they are bones situated in the chest and shoulder areas, not in the back where the vertebral column is found.

4. 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.

5. How do vaccines primarily function within the body?

• A. Creating a physical barrier against pathogens
• B. Triggering an inflammatory response
• C. Developing immunological memory to a specific pathogen
• D. Activating phagocytes to engulf pathogens

Correct answer: C

Rationale: Vaccines primarily function by stimulating the immune system to develop immunological memory to a specific pathogen. When a vaccine is administered, it exposes the immune system to a harmless version of a pathogen or a piece of it. This exposure triggers the immune response, leading to the production of antibodies and memory cells specific to that pathogen. Choice A is incorrect because vaccines do not create a physical barrier; rather, they prepare the immune system to recognize and fight specific pathogens. Choice B is incorrect as vaccines do trigger an immune response, but the primary goal is to create memory rather than inflammation. Choice D is incorrect as vaccines do not directly activate phagocytes; instead, they stimulate the immune system to generate a targeted response against a particular pathogen.

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