Nursing Elites

1. Which of the following minerals is important for bone health and is stored in bones by the skeletal system?

• A. Iron
• B. Sodium
• C. Calcium
• D. Magnesium

Correct answer: C

Rationale: The correct answer is Calcium (Choice C). Calcium is essential for bone health and is stored in bones by the skeletal system. Bones act as a reservoir for calcium, playing a critical role in maintaining bone strength and density. Iron, sodium, and magnesium are important for various bodily functions but are not primarily stored in bones for bone health. Iron is crucial for oxygen transport, sodium helps regulate fluid balance, and magnesium is involved in over 300 enzymatic reactions in the body.

2. Smooth muscle is the only ____________ muscle in the body.

• A. Voluntary, striated
• B. Involuntary, non-striated
• C. Involuntary, striated
• D. Voluntary, non-striated

Correct answer: B

Rationale: Smooth muscle is the only involuntary, non-striated muscle type in the body. It is found in organs like the intestines and blood vessels, where it controls movements without conscious effort. Choice A is incorrect because voluntary muscles are under conscious control, while smooth muscle is involuntary. Choice C is incorrect because striations are not present in smooth muscle, unlike skeletal muscle. Choice D is incorrect because smooth muscle is not voluntary and lacks striations, making it different from skeletal muscle.

3. Dysentery is an infectious disease caused by which type of microbe?

• A. Helminth
• B. Bacteria
• C. Protozoan
• D. Fungus

Correct answer: B

Rationale: The correct answer is B: Bacteria. Dysentery is typically caused by bacterial infections, such as Shigella, Campylobacter, or Escherichia coli. While parasites and protozoa can also cause similar symptoms, bacterial infections are the most common causes of dysentery. Choice A (Helminth) is incorrect as helminths are parasitic worms that typically cause different types of infections. Choice C (Protozoan) is incorrect as some protozoa like Entamoeba histolytica can cause dysentery, but bacterial infections are more common. Choice D (Fungus) is incorrect as fungal infections do not typically cause dysentery.

4. Which of the following describes a responsibility of the integumentary system?

• A. Distributing vital substances, such as nutrients, throughout the body.
• B. Blocking pathogens that cause disease.
• C. Sending leaked fluids from the cardiovascular system back to the blood vessels.
• D. Storing bodily hormones that influence gender traits.

Correct answer: B

Rationale: The correct responsibility of the integumentary system is to act as a barrier that blocks pathogens from entering the body, thus helping to prevent diseases and infections. This function serves as the first line of defense for the body against external threats. Choices A, C, and D are incorrect. Choice A is a function of the circulatory system, not the integumentary system. Choice C relates to the lymphatic system, not the integumentary system. Choice D involves the endocrine system, not the integumentary system.

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.

Similar Questions