Nursing Elites

1. What is the primary function of the endocrine system?

• A. To fight infection
• B. To transport oxygen
• C. To regulate body functions through hormones
• D. To break down food

Correct answer: C

Rationale: The correct answer is C: 'To regulate body functions through hormones.' The endocrine system is responsible for producing and secreting hormones that help regulate various body functions such as growth, metabolism, reproduction, and mood. It does not primarily function to fight infection (A), transport oxygen (B), or break down food (D). While the immune system fights infection, the respiratory system transports oxygen, and the digestive system breaks down food, the main role of the endocrine system is to maintain homeostasis by coordinating and controlling bodily functions through the release of hormones.

2. What is the valve that prevents blood from flowing back from the left ventricle into the left atrium?

• A. Tricuspid valve
• B. Mitral valve
• C. Aortic valve
• D. Pulmonic valve

Correct answer: B

Rationale: The correct answer is the Mitral valve. The mitral valve is located between the left atrium and the left ventricle of the heart. Its function is to prevent the backflow of blood from the left ventricle into the left atrium during ventricular contraction. Choice A, the Tricuspid valve, is incorrect as it is located between the right atrium and right ventricle. Choice C, the Aortic valve, and Choice D, the Pulmonic valve, are also incorrect as they are involved in the circulation of blood leaving the heart rather than preventing backflow within the atria and ventricles.

3. Which type of muscle is responsible for voluntary movements?

• A. Smooth
• B. Skeletal
• C. Cardiac
• D. Involuntary

Correct answer: B

Rationale: The corrected question is asking about the type of muscle responsible for voluntary movements, which is skeletal muscle (Choice B). Skeletal muscle is under conscious control and is responsible for voluntary movements like walking or lifting objects. Smooth muscle (Choice A) is found in organs like the intestines and blood vessels, responsible for involuntary movements. Cardiac muscle (Choice C) is specific to the heart and is also involuntary. 'Involuntary' (Choice D) is a general term and does not specify a type of muscle responsible for voluntary movements.

4. What property of a substance refers to its ability to be drawn into thin wires without breaking?

• A. Malleability
• B. Viscosity
• C. Ductility
• D. Conductivity

Correct answer: C

Rationale: Ductility is the property that allows a substance to be drawn into thin wires without breaking. Malleability, on the other hand, is the ability to be hammered or rolled into thin sheets. Viscosity is the measure of a fluid's resistance to flow. Conductivity, lastly, refers to a substance's ability to conduct electricity or heat. Therefore, in this context, the correct answer is ductility as it specifically relates to the ability of a substance to be drawn into thin wires without breaking.

5. What is the main function of vacuoles in plant cells?

• A. To provide structural support for the cell
• B. To transport substances in and out of the cell
• C. To synthesize proteins and lipids
• D. To store water, enzymes, and waste products

Correct answer: D

Rationale: Vacuoles in plant cells primarily function as storage organelles. They store water, enzymes, pigments, and waste products, helping to maintain turgor pressure within the cell. This turgor pressure provides structural support for the plant cell. While vacuoles can also participate in transporting substances within the cell, their main role is storage. The synthesis of proteins and lipids is mainly handled by other organelles such as the endoplasmic reticulum and Golgi apparatus. Choice A is incorrect because while vacuoles indirectly contribute to structural support by maintaining turgor pressure, their primary function is storage. Choice B is incorrect as vacuoles are not primarily responsible for transporting substances in and out of the cell. Choice C is incorrect as vacuoles do not synthesize proteins and lipids; this function is carried out by other organelles.

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