Nursing Elites

1. Which of the following biological macromolecules is non-soluble, composed of hydrocarbons, and acts as an important source of energy storage for the body?

• A. carbohydrates
• B. nucleic acids
• C. lipids
• D. proteins

Correct answer: C

Rationale: Lipids are non-soluble biological macromolecules composed mostly of hydrocarbons such as fatty acids. They act as an essential source of energy storage for the body, providing efficient storage of energy in the form of fats. Carbohydrates are also an energy source for the body, but lipids excel in long-term energy storage. Nucleic acids are not known for energy storage; instead, they are involved in genetic information transmission and protein synthesis. Proteins play diverse roles in the body, such as enzymatic functions, structural support, and immune response, but they are not primarily known as a source of energy storage.

2. How are mass and inertia related?

• A. Mass is a measure of inertia
• B. Mass has no relationship with inertia
• C. Inertia is a measure of weight
• D. Inertia increases with decreasing mass

Correct answer: A

Rationale: Mass is a measure of inertia. Inertia is the resistance of an object to changes in its state of motion, and mass quantifies this resistance. Objects with more mass have greater inertia, meaning they are more resistant to changes in their motion. Therefore, mass and inertia are directly related, with mass being a fundamental factor that determines the level of inertia an object possesses. Choice B is incorrect because mass and inertia are indeed related. Choice C is incorrect as inertia is not a measure of weight but rather a property related to an object's mass. Choice D is incorrect because inertia actually increases with increasing mass, not decreasing mass.

3. Which term refers to a molecule of DNA and structural protein?

• A. Lysosome
• B. Centrosome
• C. Chromosome
• D. Genome

Correct answer: C

Rationale: The correct answer is C: Chromosome. A chromosome is a structure composed of DNA and proteins that carries genetic information. It is the condensed form of DNA associated with structural proteins, not just a molecule of DNA or protein. Lysosomes are membrane-bound organelles containing digestive enzymes, not DNA and protein. Centrosomes are involved in cell division, not related to DNA and protein together. A genome refers to an organism's complete set of DNA, not specifically a molecule containing both DNA and structural protein.

4. Which of the following is NOT a factor affecting the rate of a chemical reaction?

• A. Concentration of reactants
• B. Temperature
• C. Presence of a catalyst
• D. Color of the reaction mixture

Correct answer: D

Rationale: The color of the reaction mixture is not a factor affecting the rate of a chemical reaction. Factors such as the concentration of reactants, temperature, and the presence of a catalyst can influence the rate of a chemical reaction by affecting the frequency of collisions between reactant molecules and the energy of those collisions. The color of the reaction mixture is a physical property and does not directly impact the kinetics or speed of the reaction process. It is a qualitative observation that does not alter the reaction rate or mechanisms involved.

5. What controls the involuntary, rhythmic contractions of the heart muscle?

• A. Lungs
• B. Brain
• C. Spinal cord
• D. Sinoatrial node (located within the heart)

Correct answer: D

Rationale: The correct answer is D: Sinoatrial node (located within the heart). The involuntary, rhythmic contractions of the heart muscle are controlled by a specialized group of cells located within the heart called the sinoatrial node (SA node). The SA node acts as the heart's natural pacemaker, producing electrical impulses that regulate the heart rate and synchronize the contractions of the heart muscle. Choices A, B, and C (Lungs, Brain, Spinal cord) are not responsible for directly influencing the rhythmic contractions of the heart muscle.

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