Nursing Elites

1. Which structure in the body is responsible for detecting light and converting it into signals for the brain?

• A. Iris
• B. Retina
• C. Lens
• D. Pupil

Correct answer: B

Rationale: The correct answer is the Retina. The retina in the eye contains specialized cells called photoreceptors that detect light and convert it into neural signals. These signals are then transmitted to the brain via the optic nerve for visual processing. The iris is responsible for controlling the amount of light entering the eye by adjusting the size of the pupil, while the lens helps focus light onto the retina. The pupil is simply the opening in the center of the iris that allows light to enter the eye.

2. Which of the following best describes the relationship among density, volume, and mass?

• A. As volume increases, density decreases.
• B. As volume decreases, density increases.
• C. An object's mass does not affect its density.
• D. As volume decreases, mass increases.

Correct answer: B

Rationale: The correct answer is B: 'As volume decreases, density increases.' This is because density is defined as mass divided by volume. When volume decreases and mass remains constant, the ratio of mass to volume increases, leading to higher density. Choice A is incorrect because as volume increases, density typically remains constant or increases due to the mass also increasing. Choice C is incorrect because an object's density is directly influenced by its mass. Choice D is incorrect as decreasing volume does not lead to an increase in mass.

3. What is the formula to calculate work?

• A. Work = Force × Distance
• B. Work = Mass × Velocity
• C. Work = Power × Time
• D. Work = Energy ÷ Time

Correct answer: A

Rationale: Work is defined as the product of the force applied to an object and the distance over which the force is applied. The formula to calculate work is represented by Work = Force × Distance, where force is the applied force on an object and distance is the displacement over which the force is applied. Therefore, the correct formula to calculate work is Work = Force × Distance. Choice B, 'Work = Mass × Velocity,' is incorrect because work involves force and distance, not mass and velocity. Choice C, 'Work = Power × Time,' is incorrect because work is not directly calculated using power and time. Choice D, 'Work = Energy ÷ Time,' is incorrect because work is not typically calculated by dividing energy by time; rather, it involves the product of force and distance.

4. What is the basic structural and functional unit of the nervous system?

• A. Axon
• B. Neuron
• C. Dendrite
• D. Synapse

Correct answer: B

Rationale: The correct answer is B: Neuron. Neurons are indeed the basic structural and functional units of the nervous system. Neurons are specialized cells that transmit signals throughout the nervous system, enabling communication and coordination of various functions within the body. While axons, dendrites, and synapses are all essential components of neurons and neural function, the neuron as a whole is considered the fundamental building block responsible for signal transmission. Choice A, Axon, is incorrect because an axon is a part of a neuron responsible for transmitting electrical signals away from the cell body. Choice C, Dendrite, is incorrect because dendrites are extensions of a neuron that receive signals from other neurons. Choice D, Synapse, is incorrect because a synapse is the junction between two neurons where signals are transmitted.

5. Vacuoles are large sacs for storage in plant cells. What is their main function in animal cells?

• A. Protein synthesis
• B. Waste storage and disposal
• C. Photosynthesis
• D. Cellular respiration

Correct answer: B

Rationale: Vacuoles in animal cells primarily function in waste storage and disposal, helping to maintain cellular homeostasis by storing waste products and aiding in their removal from the cell. Unlike plant cells, animal cells do not typically use vacuoles for storage purposes such as water, nutrients, or pigments. Instead, animal cells rely on other organelles like lysosomes for waste management and maintaining cellular balance. Choices A, C, and D are incorrect because protein synthesis occurs in ribosomes, photosynthesis takes place in chloroplasts (absent in animal cells), and cellular respiration mainly occurs in mitochondria, respectively. Vacuoles in animal cells serve a different purpose compared to plant cells.

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