Nursing Elites

1. Which of the following quantities do catalysts alter to control the rate of a chemical reaction?

• A. Substrate energy
• B. Activation energy
• C. Inhibitor energy
• D. Promoter energy

Correct answer: B

Rationale: The correct answer is B: Activation energy. Catalysts function by reducing the activation energy needed for a chemical reaction to proceed. By lowering the activation energy, catalysts facilitate the reaction without being consumed themselves. Substrate energy, inhibitors, and promoters are not directly altered by catalysts in the same way activation energy is. Substrate energy refers to the energy of the reactants, which is not altered by catalysts. Inhibitors increase the activation energy required for a reaction, while promoters enhance the effectiveness of a catalyst but do not represent a quantity altered by catalysts.

2. Which of the following statements regarding the pericardium is not correct?

• A. It allows for the heart to work in a relatively friction-free environment
• B. It is a single-walled layer around the heart
• C. It prevents overfilling of the heart with blood
• D. It protects and anchors the heart

Correct answer: B

Rationale: The correct statement about the pericardium is that it is double-walled, not single-walled. Choice A is correct because the pericardium does allow the heart to work in a relatively friction-free environment, reducing friction during heartbeats. Choice C is correct as the pericardium helps prevent the overfilling of the heart with blood. Choice D is also correct as the pericardium serves to protect and anchor the heart in place within the chest cavity.

3. Two objects with equal masses collide head-on, both initially moving at the same speed. After the collision, they stick together. What is their final velocity?

• A. Zero
• B. Half their initial velocity
• C. Their initial velocity
• D. Twice their initial velocity

Correct answer: C

Rationale: In an inelastic collision where two objects stick together after colliding, momentum is conserved. Since the two objects have equal masses and equal initial velocities but opposite directions, their momenta cancel out. Therefore, after the collision, the combined mass will move at the same speed as the initial velocity, but in the direction of one of the objects. Choice A ('Zero') is incorrect because momentum is conserved, and the objects must move after the collision. Choice B ('Half their initial velocity') is incorrect as the final velocity is the same as the initial velocity due to momentum conservation. Choice D ('Twice their initial velocity') is incorrect as the final velocity cannot be twice the initial velocity based on the conservation of momentum principle.

4. What type of force opposes the motion of an object moving through a fluid (liquid or gas)?

• A. Gravitational force
• B. Tension force
• C. Viscous force
• D. Magnetic force

Correct answer: C

Rationale: When an object moves through a fluid, it experiences resistance due to the viscosity of the fluid. This resistance is known as the viscous force, which opposes the motion of the object. Gravitational force is the force of attraction between two objects with mass, tension force is the force transmitted through a string, and magnetic force is the force exerted by magnets. In the context of an object moving through a fluid, the force opposing its motion is the viscous force because it resists the relative motion of the object through the fluid.

5. Which of the following is NOT a characteristic of mitosis?

• A. The replication of DNA
• B. The condensation of chromosomes
• C. The separation of sister chromatids
• D. The formation of haploid cells

Correct answer: D

Rationale: Rationale: A) The replication of DNA is a characteristic of mitosis. Before cell division occurs, the DNA is replicated to ensure that each daughter cell receives a complete set of genetic information. B) The condensation of chromosomes is a characteristic of mitosis. During mitosis, the chromosomes condense and become visible under a microscope as distinct structures. C) The separation of sister chromatids is a crucial step in mitosis. During anaphase, the sister chromatids are pulled apart and move to opposite poles of the cell to ensure that each daughter cell receives a complete set of chromosomes. D) The formation of haploid cells is NOT a characteristic of mitosis. Mitosis results in the formation of two identical diploid daughter cells, each containing the same number of chromosomes as the parent cell. Haploid cells are typically formed through the process of meiosis, not mitosis.

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