Nursing Elites

1. Which type of blood cell is primarily responsible for fighting infections?

• A. Red blood cell
• B. White blood cell
• C. Platelet
• D. Plasma

Correct answer: B

Rationale: The correct answer is B: White blood cell. White blood cells are the primary cells responsible for fighting infections and foreign invaders in the body. Red blood cells carry oxygen to tissues, platelets help in blood clotting to prevent excessive bleeding, and plasma is the liquid component of blood that carries cells and nutrients. White blood cells, also known as leukocytes, play a crucial role in the immune system by identifying and destroying pathogens, such as bacteria, viruses, and other harmful substances. Therefore, they are the key players in the body's defense against infections, making them the correct answer in this scenario. While red blood cells, platelets, and plasma have essential functions in the body, they are not primarily responsible for combating infections like white blood cells.

2. What property of matter explains why ice floats on water?

• A. Viscosity
• B. Density
• C. Buoyancy
• D. Surface tension

Correct answer: C

Rationale: The correct answer is C, buoyancy. Ice floats on water due to buoyancy, a property of matter. When water freezes into ice, it becomes less dense than liquid water, causing it to float. This phenomenon occurs because the molecules in ice are more spread out compared to liquid water, resulting in ice being less dense and able to float on the surface. Choice A, viscosity, is incorrect because viscosity refers to a fluid's resistance to flow, not its ability to float. Choice B, density, is incorrect because while ice being less dense than water is the reason it floats, this choice does not explain the specific property that causes this phenomenon. Choice D, surface tension, is incorrect as it pertains to the cohesive forces between molecules at the surface of a liquid, not the reason why ice floats on water.

3. Which of the following is a common characteristic of alkynes?

• A. They have a triple bond between carbon atoms.
• B. They are saturated hydrocarbons.
• C. They contain only single bonds.
• D. They are aromatic compounds.

Correct answer: A

Rationale: The correct answer is A. Alkynes are hydrocarbons characterized by at least one triple bond between carbon atoms. This triple bond sets them apart from alkanes, which only have single bonds, and alkenes, which feature at least one double bond. The presence of a triple bond makes alkynes unsaturated hydrocarbons. Choice B is incorrect as alkynes are unsaturated hydrocarbons, not saturated. Choice C is incorrect because alkynes contain at least one triple bond, making them different from compounds with only single bonds. Choice D is incorrect because aromatic compounds have a distinct cyclic structure with resonance stabilization, a feature not shared by alkynes.

4. Which form of energy is associated with the motion of an object?

• A. Kinetic energy
• B. Potential energy
• C. Thermal energy
• D. Electrical energy

Correct answer: A

Rationale: Kinetic energy is the form of energy associated with the motion of an object. When an object is in motion, it possesses kinetic energy due to its movement. Potential energy, on the other hand, is stored energy that an object has due to its position or condition. Thermal energy is related to heat, while electrical energy is associated with the flow of electric charge. In this case, the correct answer is kinetic energy as it directly correlates with the motion of an object.

5. What is the primary function of the mucous membrane lining the muscular tube connecting the mouth to the stomach?

• A. Secretion of digestive enzymes
• B. Absorption of nutrients
• C. Lubrication and protection
• D. Storage of bile

Correct answer: C

Rationale: The primary function of the mucous membrane lining the muscular tube connecting the mouth to the stomach is to provide lubrication and protection. This mucous membrane serves to protect the esophageal lining from damage caused by the passage of food and liquids. It also aids in facilitating the smooth passage of food from the mouth to the stomach by lubricating it, ensuring easier movement. Choices A, B, and D are incorrect as the mucous membrane does not secrete digestive enzymes, absorb nutrients, or store bile. Its main role is primarily related to lubricating and protecting the lining of the tube.

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