Nursing Elites

1. Centrioles are structures involved in cell division. What is their specific role?

• A. Forming the nuclear envelope
• B. Replicating DNA
• C. Organizing microtubules during cell division
• D. Protein synthesis

Correct answer: C

Rationale: Centrioles are involved in organizing microtubules during cell division, specifically in forming the mitotic spindle. The mitotic spindle is crucial for the proper alignment and separation of chromosomes during cell division, ensuring the accurate distribution of genetic material to daughter cells. Choice A, forming the nuclear envelope, is incorrect as centrioles do not have a direct role in this process. Choice B, replicating DNA, is incorrect as centrioles are not involved in DNA replication. Choice D, protein synthesis, is incorrect as centrioles do not play a role in protein synthesis.

2. Which of the following is a constant?

• A. The number of protons in an oxygen atom
• B. The temperature at which iron ore will melt
• C. The human population size
• D. The time the sun rises each day

Correct answer: A

Rationale: The number of protons in an oxygen atom is a constant. This value is determined by the atomic number of the element and does not change regardless of the isotope of oxygen. The number of protons defines the element and remains consistent under normal conditions. Choices B, C, and D are not constants. The temperature at which iron ore will melt can vary depending on factors like pressure, the human population size is constantly changing, and the time the sun rises each day varies with the seasons and location.

3. What is the primary function of the atrioventricular (AV) node within the heart?

• A. Generate the electrical impulse for contraction (pacemaker function)
• B. Transmit the electrical impulse from the atria to the ventricles, regulating the timing of contraction.
• C. Increase blood pressure within the ventricles during systole.
• D. Separate oxygenated and deoxygenated blood flow in the heart.

Correct answer: B

Rationale: The correct answer is B: Transmit the electrical impulse from the atria to the ventricles, regulating the timing of contraction. The primary function of the atrioventricular (AV) node is to coordinate the transmission of electrical signals between the atria and the ventricles. It ensures proper timing between atrial and ventricular contractions, allowing for efficient blood pumping through the heart. Choice A is incorrect because the AV node does not generate the initial electrical impulse; that role is typically attributed to the sinoatrial (SA) node. Choice C is incorrect as the AV node does not directly influence blood pressure within the ventricles. Choice D is also incorrect as the separation of oxygenated and deoxygenated blood is primarily achieved by the anatomical structure of the heart (e.g., atria and ventricles) and not the AV node.

4. Which type of chemical reaction produces a salt?

• A. An oxidation reaction
• B. A neutralization reaction
• C. A synthesis reaction
• D. A decomposition reaction

Correct answer: B

Rationale: The correct answer is B, a neutralization reaction. In a neutralization reaction, an acid and a base react to produce a salt and water. This process involves the combination of H+ ions from the acid and OH- ions from the base to form water, while the remaining ions combine to form a salt. Therefore, a neutralization reaction is the specific type of chemical reaction that produces a salt. Choices A, C, and D are incorrect. An oxidation reaction involves the loss of electrons, a synthesis reaction involves the formation of a compound from simpler substances, and a decomposition reaction involves the breakdown of a compound into simpler substances. None of these reactions directly lead to the production of a salt, making them incorrect choices in this context.

5. Which of the following statements is FALSE?

• A. An organelle is a specialized structure in a cell, such as a ribosome.
• B. An organ is made up of different types of tissues that work together to perform specific functions.
• C. Organ systems are two or more organs performing similar functions.
• D. A tissue contains a variety of cells that work together to perform a specific function.

Correct answer: B

Rationale: The statement provided in Option B is FALSE. Organs are actually made up of different types of tissues that work together to perform specific functions, rather than being composed of similar tissues. Organs consist of various tissues, each with their own specialized functions that collectively contribute to the overall function of the organ. Options A, C, and D are true statements. Option A correctly defines an organelle as a specialized structure in a cell, like a ribosome. Option C accurately describes organ systems as multiple organs working together to perform related functions. Option D correctly explains that a tissue is composed of different cells working together to carry out a specific function.

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