Nursing Elites

1. What is the work done by a force of 20 N acting on an object that moves 5 meters in the direction of the force?

• A. 100 Joules (J)
• B. 25 Joules (J)
• C. 4 Joules (J)
• D. Work cannot be determined without knowing the object's mass.

Correct answer: A

Rationale: The work done is calculated using the formula: Work = Force x Distance x cos(theta), where theta is the angle between the force and the direction of motion. In this case, the force and the direction of motion are in the same direction, so cos(theta) = 1. Therefore, Work = 20 N x 5 m x 1 = 100 Joules. Since the force and distance are given and are in the same direction, the work done can be directly calculated without needing to know the object's mass. Choice A, 100 Joules, is the correct answer as calculated. Choice B and C are incorrect as they do not correspond to the correct calculation. Choice D is incorrect because knowing the object's mass is not necessary to calculate work in this scenario, as work is dependent on force, distance, and the angle between them, not mass.

2. What happens to the wavelength of a wave when its frequency increases while the speed remains constant?

• A. Wavelength increases
• B. Wavelength decreases
• C. Wavelength remains the same
• D. Wavelength becomes zero

Correct answer: B

Rationale: When the speed of a wave is constant and the frequency increases, the wavelength must decrease to keep the speed constant. The speed of a wave is determined by the product of frequency and wavelength (speed = frequency x wavelength). If the frequency increases while the speed remains constant, the wavelength has to decrease proportionally to maintain the speed unchanged. Therefore, as the frequency increases, the wavelength decreases to ensure that the speed of the wave remains constant. Choice A is incorrect because as frequency increases, wavelength decreases. Choice C is incorrect as the wavelength cannot remain the same when frequency increases while speed is constant. Choice D is incorrect as the wavelength cannot become zero under these conditions.

3. Which transport mechanism uses vesicles to move materials out of the cell?

• A. Endocytosis
• B. Active transport
• C. Diffusion
• D. Exocytosis

Correct answer: D

Rationale: Exocytosis is the transport mechanism that uses vesicles to move materials out of the cell. Vesicles carry substances to the cell membrane, fuse with it, and release their contents outside the cell. This process is essential for secreting molecules such as hormones, enzymes, or neurotransmitters. Endocytosis, on the other hand, is the process of bringing materials into the cell by engulfing them in vesicles. Active transport involves the movement of molecules across a cell membrane against their concentration gradient, requiring energy. Diffusion is the passive movement of molecules from an area of higher concentration to an area of lower concentration.

4. Which nitrogenous bases pair with each other in DNA?

• A. A-G and T-C
• B. A-T and C-G
• C. A-T and T-T
• D. C-C and G-G

Correct answer: B

Rationale: In DNA, nitrogenous bases pair with each other in a specific manner known as complementary base pairing. Adenine (A) always pairs with Thymine (T), and Cytosine (C) always pairs with Guanine (G). This pairing is essential for maintaining the structure and function of DNA. Option B is the correct answer as it correctly identifies the nitrogenous bases that pair with each other in DNA. Choices A, C, and D are incorrect because they do not follow the established base pairing rules in DNA. A-T and C-G are the complementary base pairs in DNA, ensuring the stability and replication fidelity of the genetic material.

5. What is a mutation?

• A. A change in the DNA sequence
• B. A type of protein
• C. A normal part of the DNA replication process
• D. A harmless variation in DNA

Correct answer: A

Rationale: A mutation is defined as a change in the DNA sequence, which can occur due to various factors such as errors during DNA replication, exposure to mutagens (e.g., chemicals, radiation), or spontaneous changes. These alterations can lead to modifications in the genetic information carried by an organism, resulting in effects that can range from harmless variations to causing genetic disorders or diseases. Mutations play a crucial role in genetic diversity and evolution. Choices B, C, and D are incorrect as they do not accurately define what a mutation is. Option B is incorrect because mutations are not a type of protein but rather changes in DNA. Option C is incorrect because while mutations can occur during DNA replication, they are not considered a 'normal' part of the process as they can lead to genetic variations. Option D is incorrect because mutations can have a wide range of effects and are not always harmless variations.

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