Nursing Elites

1. Which human body system is correctly matched with its function?

• A. Respiratory system; exchanges oxygen and carbon dioxide in the lungs.
• B. Circulatory system; transports oxygen to cells and removes carbon dioxide.
• C. Lymphatic system; produces antibodies that destroy virally affected or foreign cells.
• D. Endocrine system; regulates hormones controlling bodily functions and metabolism.

Correct answer: B

Rationale: The circulatory system is responsible for the transportation of oxygen from the lungs to all the body's cells and tissues, as well as removing carbon dioxide from the cells and transporting it back to the lungs to be exhaled. This process is crucial for cellular respiration and the exchange of gases necessary for bodily functions. Choice B accurately matches the role of the circulatory system by describing its function of transporting oxygen to cells and removing carbon dioxide, which is essential for maintaining proper cellular activities. Choices A, C, and D are incorrect because they do not accurately match the body system with its function. The respiratory system primarily involves the exchange of gases in the lungs, not transportation to cells; the lymphatic system deals with immunity through the production of antibodies, not gas exchange; and the endocrine system's main function is hormone regulation, not the transport of gases.

2. What is the main target organ for insulin, the hormone produced by the pancreas?

• A. Liver
• B. Kidneys
• C. Muscles
• D. Brain

Correct answer: C

Rationale: The main target organ for insulin is muscles. Insulin plays a crucial role in regulating glucose metabolism by promoting the uptake of glucose into muscle cells. This glucose can then be utilized for energy production or stored for later use. Therefore, muscles are the primary site where insulin exerts its effects on glucose uptake and utilization. The liver primarily responds to insulin by regulating glucose storage and release, but the main target for insulin-mediated glucose uptake is muscles. Kidneys are not a target organ for insulin action in glucose metabolism. The brain does not heavily rely on insulin for glucose uptake as it primarily uses glucose independently of insulin for energy production.

3. What type of reaction is represented by the following equation: 2C₆H₁₄ + 19O₂ → 12CO + 14H₂O?

• A. Substitution reaction
• B. Acid-base reaction
• C. Enzyme reaction
• D. Combustion reaction

Correct answer: D

Rationale: The given chemical equation represents a combustion reaction. Combustion reactions involve the burning of a hydrocarbon (C₆H₁₄) in the presence of oxygen (O₂) to produce carbon monoxide (CO) and water (H₂O). Combustion reactions typically release heat and light energy. In this case, the reactants are a hydrocarbon and oxygen, resulting in the formation of carbon monoxide and water. Choices A, B, and C are incorrect because the reaction does not involve substitution, acid-base reactions, or enzyme catalysis. Combustion reactions are characterized by the rapid combination of a substance with oxygen, leading to the production of heat and light energy.

4. Which of the following structures is responsible for filtering blood in the kidneys?

• A. Ureter
• B. Glomerulus
• C. Nephron
• D. Renal artery

Correct answer: B

Rationale: The correct answer is B: Glomerulus. The glomerulus, located in the nephron of the kidney, is a network of tiny blood vessels responsible for filtering blood. It removes waste products and excess substances to form urine. The ureter carries urine from the kidneys to the bladder and is not involved in blood filtration. The nephron is the functional unit of the kidney where blood is filtered and urine is produced. The renal artery supplies blood to the kidneys but is not directly involved in the filtration process.

5. Which of the following is unique to covalent bonds?

• A. Most covalent bonds are formed between the elements H, F, N, and O.
• B. Covalent bonds are dependent on forming dipoles.
• C. Bonding electrons are shared between two or more atoms.
• D. Molecules with covalent bonds tend to have a crystalline solid structure.

Correct answer: C

Rationale: The correct answer is C: 'Bonding electrons are shared between two or more atoms.' This statement is unique to covalent bonds. In covalent bonds, atoms share electrons to achieve a stable electron configuration, which leads to the formation of a bond. This sharing of electrons is a fundamental characteristic of covalent bonds and distinguishes them from other types of chemical bonds, such as ionic bonds, where electrons are transferred rather than shared. Choices A, B, and D do not represent unique characteristics of covalent bonds. Choice A describes some common elements involved in covalent bonds, choice B refers to the concept of dipoles, which can also exist in other types of bonds, and choice D describes a property of molecules (crystalline solid structure) that is not exclusive to covalent bonds.

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