Nursing Elites

1. What is the initial step of the scientific method?

• A. construct a hypothesis
• B. make observations
• C. analyze data
• D. form a question

Correct answer: B

Rationale: The first step of the scientific method is to make observations. This involves collecting data and information about a specific phenomenon or problem. Observations serve as the basis for developing a question to be explored further. Forming a hypothesis (Choice A) comes after making observations, as the hypothesis is an educated guess to explain the observations. Analyzing data (Choice C) occurs later in the scientific method after data has been collected and experiments conducted. Forming a question (Choice D) is a crucial step but typically follows observations in the scientific process.

2. Which of the following components is found in DNA?

• A. Uracil
• B. Deoxyribose
• C. Guanine
• D. Phosphate group

Correct answer: B

Rationale: The correct answer is B: Deoxyribose. DNA is composed of nucleotides containing deoxyribose sugar, phosphate group, and nitrogenous bases (adenine, thymine, guanine, and cytosine). Deoxyribose is the sugar component specific to DNA, while ribose is found in RNA. Guanine (choice C) is a nitrogenous base present in both DNA and RNA. Uracil (choice A) is a nitrogenous base specific to RNA, replacing thymine found in DNA. The phosphate group (choice D) is an essential part of nucleotides in both DNA and RNA, providing the backbone structure for the nucleic acid chains.

3. Which blood vessel carries oxygenated blood back to the heart?

• A. Pulmonary vein
• B. Pulmonary artery
• C. Aorta
• D. Superior vena cava

Correct answer: A

Rationale: The corrected question is asking for a blood vessel that carries oxygenated blood back to the heart. The pulmonary vein is the correct choice as it carries oxygenated blood from the lungs back to the heart during systemic circulation. The pulmonary artery carries deoxygenated blood from the heart to the lungs for oxygenation. The aorta is the main artery that carries oxygenated blood away from the heart to the body. The superior vena cava returns deoxygenated blood from the upper body back to the heart.

4. What are the differences between RNA and DNA?

• A. Both have the same structure and function.
• B. RNA is single-stranded, while DNA is double-stranded.
• C. RNA contains ribose sugar, while DNA contains deoxyribose sugar.
• D. RNA has adenine and guanine, while DNA has thymine and cytosine.

Correct answer: B

Rationale: A) This statement is incorrect. RNA and DNA have different structures and functions. RNA is involved in protein synthesis and other cellular processes, while DNA stores genetic information. B) This statement is correct. RNA is typically single-stranded, while DNA is double-stranded, forming a double helix structure. C) This statement is correct. RNA contains ribose sugar in its backbone, while DNA contains deoxyribose sugar. D) This statement is incorrect. RNA contains adenine, guanine, cytosine, and uracil, while DNA contains adenine, guanine, cytosine, and thymine. Choice B is the correct answer as it accurately describes one of the key differences between RNA and DNA, emphasizing their structural disparity in terms of single-strandedness for RNA and double-strandedness for DNA. Choices A, C, and D contain inaccuracies regarding the structural and compositional distinctions between RNA and DNA, making them incorrect choices.

5. Which of the following structures plays a crucial role in controlling the cell cycle and preventing uncontrolled cell growth?

• A. The centrioles
• B. The nucleolus
• C. The Golgi apparatus
• D. The endoplasmic reticulum

Correct answer: A

Rationale: The correct answer is A: The centrioles. Centrioles are cylindrical structures found in animal cells that are crucial in organizing the spindle fibers during cell division (mitosis). They play a vital role in separating chromosomes during cell division, ensuring each daughter cell receives the correct number of chromosomes. Additionally, centrioles are involved in the formation of cilia and flagella, essential for cell motility and sensory functions. The nucleolus is responsible for ribosome production, the Golgi apparatus processes and packages proteins, and the endoplasmic reticulum is involved in protein synthesis and lipid metabolism. These structures do not have a direct role in controlling the cell cycle and preventing uncontrolled cell growth.

Similar Questions