Nursing Elites

1. Which of the following is the base that will bind with cytosine?

• A. Adenine
• B. Cytosine
• C. Guanine
• D. Thymine

Correct answer: A

Rationale: Adenine is the correct answer as it is the base that binds with cytosine through hydrogen bonding in DNA, forming the A-T base pair. Cytosine always pairs with guanine to form the G-C base pair. Thymine pairs with adenine in DNA, not with cytosine.

2. What happens to the density of a substance if its mass increases while its volume remains constant?

• A. Density increases
• B. Density decreases
• C. Density remains constant
• D. Density becomes zero

Correct answer: A

Rationale: When the mass of a substance increases while its volume remains constant, the density, which is calculated by dividing mass by volume, will increase. This is because with a higher mass and the volume staying the same, the ratio of mass to volume (density) will be greater, resulting in an overall increase in density. Choice B, 'Density decreases,' is incorrect because an increase in mass with constant volume leads to a higher density. Choice C, 'Density remains constant,' is incorrect as an increase in mass will cause the density to increase. Choice D, 'Density becomes zero,' is incorrect because even with an increase in mass, as long as volume remains constant, density will not reach zero; it will increase instead.

3. How can you differentiate between a bacterial and viral infection based solely on symptoms?

• A. It's impossible to differentiate solely based on symptoms.
• B. Bacterial infections typically respond well to antibiotics, while viral infections don't.
• C. Bacterial infections usually cause fever, while viral infections don't.
• D. Viral infections often present with respiratory symptoms like a cough, while bacterial infections don't.

Correct answer: A

Rationale: It is impossible to differentiate between a bacterial and viral infection based solely on symptoms because many symptoms overlap between the two types of infections. Symptoms like fever, cough, and others can be present in both bacterial and viral infections. Additional diagnostic tests such as cultures or blood tests are often needed to determine the cause of the infection accurately. Relying only on symptoms can lead to misdiagnosis and inappropriate treatment. Choices B, C, and D are incorrect because they oversimplify the differentiation process and do not encompass the complexity of symptoms associated with bacterial and viral infections. While it is true that bacterial infections may respond to antibiotics and some differences in symptoms may be observed between bacterial and viral infections, these are not definitive indicators without proper diagnostic tests.

4. What is the 'lock-and-key' model?

• A. Protein folding
• B. Enzyme-substrate interaction
• C. Muscle contraction
• D. Blood clotting

Correct answer: B

Rationale: The 'lock-and-key' model describes the specificity of the interaction between enzymes and their substrates. In this model, the enzyme's active site acts like a lock that can only be opened by the specific substrate molecule, which serves as the key. This specific binding ensures that enzymes catalyze particular reactions and do not interact with other molecules indiscriminately. Protein folding (option A) is the process by which a protein attains its functional three-dimensional structure but is not directly related to the lock-and-key model. Muscle contraction (option C) and blood clotting (option D) are complex biological processes but are not directly associated with the lock-and-key model of enzyme-substrate interaction.

5. What is the product of translation from an RNA template?

• A. DNA
• B. Lipid
• C. Polypeptide
• D. Carbohydrate

Correct answer: C

Rationale: Translation is the process by which the genetic information carried by mRNA is decoded to synthesize a polypeptide chain. This essential process occurs at the ribosomes within the cell. The product of translation from an RNA template is a polypeptide, not DNA, lipid, or carbohydrate. DNA is involved in transcription, lipids are not directly produced in translation, and carbohydrates are not synthesized through translation. Therefore, the correct product resulting from translation from an RNA template is a polypeptide, making choice C, 'Polypeptide,' the correct answer.

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