Nursing Elites

1. Define 'friction' in terms of opposing motion.

• A. A force that increases motion
• B. A force that accelerates motion
• C. A force that opposes motion
• D. A force that creates motion

Correct answer: C

Rationale: Friction is a force that opposes motion. When two surfaces are in contact, friction acts in the opposite direction to the motion or the potential motion between the two surfaces. It resists the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. Friction hinders or prevents motion rather than promoting it. Choices A, B, and D are incorrect as they suggest that friction increases, accelerates, or creates motion, which is inaccurate. The correct definition of friction is that it opposes motion, making choice C the most appropriate option.

2. Which factor do colligative properties of solutions depend on?

• A. Concentration of the solvent
• B. All of the above
• C. Chemical identity of the solute
• D. Number of solute particles in solution

Correct answer: D

Rationale: Colligative properties of solutions depend on the number of solute particles in solution. These properties, such as boiling point elevation, freezing point depression, vapor pressure lowering, and osmotic pressure, are proportional to the number of solute particles present in the solution. The chemical identity of the solute or the concentration of the solvent does not influence colligative properties, making choices A and C incorrect. Therefore, the correct answer is D, the number of solute particles in solution.

3. When a person throws a ball horizontally, what force changes the direction of the ball's motion?

• A. The force of throwing
• B. Gravitational force
• C. Air resistance
• D. Normal force from the ground

Correct answer: B

Rationale: When a person throws a ball horizontally, the initial force that propels the ball forward is the force of throwing (A). However, the force that changes the direction of the ball's motion is the gravitational force (B). Gravitational force acts vertically downward, causing the ball to follow a curved path. Air resistance (C) and normal force from the ground (D) do not directly change the direction of the ball's motion in this scenario.

4. What type of joint connects the bones of the skull?

• A. Hinge joint
• B. Fibrous joint
• C. Ball-and-socket joint
• D. Pivot joint

Correct answer: B

Rationale: The correct answer is B: Fibrous joint. Fibrous joints connect the bones of the skull, providing stability with little to no movement. These joints are made of fibrous connective tissue, which holds the bones tightly together and prevents movement, making them ideal for the structure of the skull. Choice A: Hinge joint is incorrect because hinge joints allow movement in a single plane like the elbow or knee, which is not characteristic of the joints in the skull. Choice C: Ball-and-socket joint is incorrect as this type of joint allows for a wide range of movement in multiple planes, such as the hip and shoulder joints, which is not the case for skull bones. Choice D: Pivot joint is incorrect as pivot joints allow rotation around a central axis, as seen in the joint between the first and second cervical vertebrae (atlas and axis), but not in the skull bones.

5. How can a single gene mutation lead to multiple phenotypes depending on the organism?

• A. Pleiotropy describes the effect of one gene influencing multiple seemingly unrelated traits.
• B. Epigenetics involves environmental factors modifying gene expression without altering the DNA sequence.
• C. Genetic drift refers to random changes in allele frequencies within a population.
• D. Gene regulation controls the timing and level of gene expression within an organism.

Correct answer: A

Rationale: A single gene mutation can lead to multiple phenotypes through pleiotropy, where one gene influences diverse traits or functions in an organism. This phenomenon occurs when the mutated gene affects different biochemical pathways, developmental processes, or cellular functions, resulting in a cascade of downstream effects that manifest as a variety of phenotypic outcomes. Choice B, epigenetics, involves modifications in gene expression influenced by environmental factors without altering the DNA sequence, which is not directly related to the question about single gene mutations causing multiple phenotypes. Choice C, genetic drift, refers to random changes in allele frequencies within a population, which is unrelated to the impact of a single gene mutation on multiple phenotypes. Choice D, gene regulation, focuses on controlling the timing and level of gene expression within an organism, which is not directly addressing how a single gene mutation can lead to diverse phenotypes.

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