Nursing Elites

1. An atom has 17 protons, 20 neutrons, and 17 electrons. What is its mass, in amu?

• A. 17
• B. 20
• C. 37
• D. 54

Correct answer: C

Rationale: The atomic mass of an atom is the sum of the protons and neutrons in its nucleus. In this case, the atom has 17 protons and 20 neutrons, totaling 37 particles in the nucleus. Electrons are not considered in the atomic mass calculation as their mass is negligible compared to protons and neutrons. Therefore, the mass of the atom in atomic mass units (amu) is 37.

2. What does the term 'solute' refer to in a solution?

• A. The substance present in the largest amount
• B. The substance that dissolves in the solvent
• C. The liquid portion of the solution
• D. The temperature at which the solution freezes

Correct answer: B

Rationale: In a solution, the term 'solute' specifically refers to the substance that dissolves in the solvent to create a solution. The solute is typically present in a smaller amount compared to the solvent. Option B correctly identifies the solute as the substance that undergoes dissolution in the solvent, making it the correct choice. Choices A, C, and D are incorrect. Choice A is actually describing the solvent, which is the substance present in the largest amount in a solution. Choice C refers to the solvent, not the solute. Choice D is unrelated to the term 'solute' as it describes the colligative property of freezing point depression, not the solute itself.

3. How is blood pressure controlled by the body?

• A. By adjusting heart rate only
• B. By regulating blood volume
• C. By baroreceptors and hormones
• D. By adjusting body temperature

Correct answer: C

Rationale: Blood pressure is controlled by baroreceptors located in the aortic arch and carotid arteries that detect changes in blood pressure levels. When blood pressure is high, these receptors signal for adjustments to lower it. Additionally, hormones such as renin from the kidneys are released when blood pressure drops, further aiding in blood pressure regulation. Choice A is incorrect because blood pressure regulation involves more than just adjusting heart rate; it also includes vasodilation and vasoconstriction. Choice B is incorrect as while blood volume can impact blood pressure, it is not the primary mechanism of blood pressure control. Choice D is incorrect as body temperature regulation is a separate physiological process and not directly related to blood pressure control.

4. What structure in plant cells provides rigidity and support?

• A. Cell membrane
• B. Golgi apparatus
• C. Plastid
• D. Cell wall

Correct answer: D

Rationale: The correct answer is D, the cell wall. The cell wall is the structure in plant cells that provides rigidity and support. It is a tough, rigid structure located outside the cell membrane. Composed primarily of cellulose, the cell wall offers structural support to the cell, helping it maintain its shape and protect it from damage. The other choices, such as the cell membrane (choice A), Golgi apparatus (choice B), and plastid (choice C) do not provide rigidity and support to plant cells. The cell membrane is a selectively permeable barrier, the Golgi apparatus is involved in processing and packaging proteins, and plastids are organelles responsible for functions like photosynthesis and storage, but they do not provide the structural support that the cell wall does.

5. What is the basic unit of heredity?

• A. Chromosome
• B. Cell
• C. Gene
• D. Organ

Correct answer: C

Rationale: A gene is the basic unit of heredity that carries the instructions for making proteins, which determine an organism's traits. Genes are segments of DNA located on chromosomes within the cell. While chromosomes contain many genes, a gene itself is the fundamental unit of heredity responsible for passing on genetic information from one generation to the next. Cells are the basic structural and functional units of living organisms, but genes specifically carry genetic information. Organs are composed of tissues and serve specific functions within an organism, but they are not the basic unit of heredity.

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