Nursing Elites

1. What is the primary function of the cell membrane?

• A. To provide structural support for the cell
• B. To transport substances in and out of the cell
• C. To synthesize proteins and lipids
• D. To store genetic material

Correct answer: B

Rationale: The primary function of the cell membrane, also known as the plasma membrane, is to regulate the movement of substances in and out of the cell. It acts as a selectively permeable barrier, allowing specific molecules to pass through while blocking others. This role is crucial for maintaining the internal environment of the cell by enabling essential nutrients to enter and waste products to exit. While the cell membrane provides some structural support for the cell, its main function is substance transport. Protein and lipid synthesis predominantly occur in organelles like the endoplasmic reticulum and Golgi apparatus, and storing genetic material is the nucleus's responsibility. Therefore, choices C (To synthesize proteins and lipids) and D (To store genetic material) are incorrect as these functions are carried out by other cell organelles, not the cell membrane.

2. What is the product of the complete combustion of propane (C3H8)?

• A. CO2
• B. CO
• C. CH4
• D. C

Correct answer: A

Rationale: The complete combustion of propane (C3H8) results in the production of carbon dioxide (CO2) and water. When a hydrocarbon such as propane undergoes complete combustion, the carbon atoms combine with oxygen to form CO2. This makes choice A, CO2, the correct answer. Choices B, C, and D are incorrect as CO is carbon monoxide, CH4 is methane, and C is elemental carbon, none of which are the primary product of the complete combustion of propane.

3. What is the significance of the nuclear envelope breaking down during mitosis?

• A. It allows the chromosomes to condense and become visible.
• B. It allows the spindle apparatus to form and attach to the chromosomes.
• C. It allows the sister chromatids to separate.
• D. It allows the nuclear material to be evenly distributed to the daughter cells.

Correct answer: B

Rationale: A) The breakdown of the nuclear envelope does not directly cause the chromosomes to condense and become visible. Chromosome condensation is a separate process that occurs before mitosis begins. B) The breakdown of the nuclear envelope is crucial for the formation of the spindle apparatus, a structure made of microtubules that helps separate the chromosomes during cell division. The spindle apparatus attaches to the chromosomes and helps move them to opposite poles of the cell. C) The separation of sister chromatids occurs during anaphase, which is facilitated by the spindle apparatus. The breakdown of the nuclear envelope is not directly involved in this process. D) The even distribution of nuclear material to daughter cells is achieved through the movement of chromosomes by the spindle apparatus, which is made possible by the breakdown of the nuclear envelope.

4. Which of the following phases of mitosis is characterized by the separation of sister chromatids and their movement to opposite poles?

• A. Metaphase
• B. Anaphase
• C. Telophase
• D. Cytokinesis

Correct answer: B

Rationale: During anaphase of mitosis, the sister chromatids, which are duplicated copies of a chromosome, separate and move towards opposite poles of the cell. This movement is facilitated by the shortening of microtubules attached to the chromatids. As a result, each pole of the cell receives a complete set of chromosomes, ensuring that the daughter cells produced after cell division will have the correct number of chromosomes. Metaphase is characterized by the alignment of chromosomes at the cell's equator, not their separation. Telophase is the phase following anaphase, where the separated chromatids reach the opposite poles and nuclear envelopes start to form around them. Cytokinesis is the final stage of cell division, where the cytoplasm is divided to form two separate daughter cells.

5. Define the term 'velocity' in relation to motion.

• A. Speed in a specific direction
• B. Distance traveled in a given time
• C. Rate of change of position
• D. Acceleration due to gravity

Correct answer: A

Rationale: Velocity is a vector quantity that describes the speed of an object along with its direction of motion. Unlike speed, which is a scalar quantity focusing solely on the magnitude of motion, velocity considers both speed and direction. Therefore, the best definition of velocity is 'speed in a specific direction.' Choice B, 'Distance traveled in a given time,' is incorrect as it defines speed rather than velocity. Choice C, 'Rate of change of position,' is more aligned with the definition of velocity but lacks the specificity of direction. Choice D, 'Acceleration due to gravity,' is unrelated to the definition of velocity and refers to a different concept in physics.

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