Nursing Elites

1. What does the number of protons in the nucleus of an atom determine?

• A. Mass number
• B. Atomic number
• C. Isotope
• D. Valence electron count

Correct answer: B

Rationale: The number of protons in the nucleus of an atom is referred to as the atomic number. This atomic number is crucial as it uniquely identifies an element and determines its position on the periodic table. The mass number, on the other hand, represents the sum of protons and neutrons in an atom's nucleus. Isotopes are variants of elements with the same number of protons but differing numbers of neutrons. Valence electron count pertains to the number of electrons in the outermost energy level of an atom, which influences its chemical behavior.

2. 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.

3. A car skids on a wet road. What is the main force preventing the car from stopping?

• A. Friction
• B. Gravitational force
• C. Normal force from the road
• D. Air resistance

Correct answer: A

Rationale: The correct answer is A: Friction. Friction is the force that opposes the motion of the car on the wet road surface, making it harder for the car to stop. When the car skids, the friction between the tires and the wet road surface is reduced, leading to a loss of traction and making it challenging for the car to come to a halt. Gravitational force (choice B) is the force that pulls objects toward each other due to gravity and does not directly impact the car's ability to stop on a wet road. The normal force from the road (choice C) is the force exerted by the road surface perpendicular to the car's tires and does not play a significant role in stopping the car. Air resistance (choice D) is the force that opposes the motion of an object through the air, but it is not the main force preventing the car from stopping on a wet road.

4. The adrenal glands are part of the

• A. immune system
• B. endocrine system
• C. lymphatic system
• D. respiratory system

Correct answer: B

Rationale: The correct answer is B: endocrine system. The adrenal glands are part of the endocrine system. These small, triangular-shaped glands are located on top of each kidney and are responsible for producing hormones such as adrenaline, cortisol, and aldosterone. These hormones play a vital role in regulating various body functions, including metabolism, immune response, and stress response. Choices A, C, and D are incorrect because the adrenal glands are not part of the immune system, lymphatic system, or respiratory system. While the immune system is involved in protecting the body from infections and diseases, the lymphatic system helps in maintaining fluid balance and immune function, and the respiratory system is responsible for breathing and gas exchange in the body.

5. What is the relationship between force and acceleration according to Newton's second law?

• A. Force is directly proportional to acceleration
• B. Force is inversely proportional to acceleration
• C. Force has no relation to acceleration
• D. Force causes deceleration, not acceleration

Correct answer: A

Rationale: According to Newton's second law of motion, the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. This relationship is mathematically expressed as F = ma, where F represents force, m represents mass, and a represents acceleration. Therefore, an increase in force will result in a proportional increase in acceleration, supporting the statement that force is directly proportional to acceleration. Choice B is incorrect as it suggests an inverse relationship, which is not consistent with Newton's second law. Choice C is incorrect because force and acceleration are indeed related as per Newton's second law. Choice D is incorrect as force can cause acceleration or deceleration depending on the direction of the force relative to the motion of the object, but it does not exclusively cause deceleration.

Similar Questions