Nursing Elites

1. How many moles of water are produced when 0.5 moles of methane (CH4) react with excess oxygen?

• A. 0.5 moles
• B. 1 mole
• C. 2 moles
• D. 3 moles

Correct answer: B

Rationale: The balanced chemical equation for the combustion of methane is: CH4 + 2O2 -> CO2 + 2H2O. This equation shows that 1 mole of methane produces 2 moles of water. Therefore, when 0.5 moles of methane react, they will produce 1 mole of water. The ratio of water to methane is 2:1, meaning that for every mole of methane that reacts, it produces 2 moles of water. Since only 0.5 moles of methane are reacting, the amount of water produced will be half of what would be produced if 1 mole of methane reacted, resulting in 1 mole of water being produced. Choice A is incorrect because it does not consider the stoichiometry of the reaction. Choices C and D are incorrect as they do not align with the balanced chemical equation and the stoichiometric ratios involved in the reaction.

2. What is the process of breaking down lipids into fatty acids and glycerol called?

• A. Lipolysis
• B. Gluconeogenesis
• C. Krebs cycle
• D. Oxidative phosphorylation

Correct answer: A

Rationale: - Lipolysis is indeed the correct answer. It is the process of breaking down lipids (fats) into fatty acids and glycerol. This process occurs in adipose tissue and is important for releasing stored energy in the form of fatty acids. - Gluconeogenesis is the process of synthesizing glucose from non-carbohydrate sources like amino acids and glycerol, not breaking down lipids. - The Krebs cycle (also known as the citric acid cycle) is a series of chemical reactions that occur in the mitochondria to generate energy through the oxidation of acetyl-CoA derived from carbohydrates, fats, and proteins. - Oxidative phosphorylation is the final stage of cellular respiration where ATP is produced through the transfer of electrons in the electron transport chain. It is not specifically related to the breakdown of lipids into fatty acids and glycerol.

3. What is the main function of white blood cells?

• A. Transport oxygen
• B. Fight infection
• C. Produce antibodies
• D. Regulate body temperature

Correct answer: B

Rationale: The main function of white blood cells is to fight infection, making choice B the correct answer. White blood cells are a crucial component of the immune system, working to defend the body against pathogens and foreign invaders. Choices A, C, and D are incorrect because white blood cells do not primarily transport oxygen, produce antibodies, or regulate body temperature. While some blood cells are involved in these functions, the primary role of white blood cells is to combat infections and maintain the body's immune response.

4. Which of the following statements regarding macrophages is incorrect?

• A. They are found abundantly in the blood
• B. They are larger than neutrophils
• C. They are long-lived
• D. They are made in the bone marrow as monocytes, called macrophages once they reach organs

Correct answer: A

Rationale: The correct answer is A. Macrophages are not found abundantly in the blood; they are present in tissues and organs. Macrophages are tissue-resident immune cells that play a key role in immune responses and are derived from monocytes produced in the bone marrow. Choice B is correct as macrophages are larger than neutrophils. Choice C is correct as macrophages are long-lived cells. Choice D is correct as macrophages originate in the bone marrow as monocytes and differentiate into macrophages once they migrate to various tissues and organs.

5. Which vitamin deficiency can lead to a condition called pernicious anemia, affecting vitamin B12 absorption in the digestive system?

• A. Vitamin A
• B. Vitamin B12 (cobalamin)
• C. Vitamin D
• D. Vitamin E

Correct answer: B

Rationale: Pernicious anemia is caused by a deficiency in vitamin B12 (cobalamin). Vitamin B12 is essential for the production of red blood cells and for the proper functioning of the nervous system. Pernicious anemia occurs when there is a lack of intrinsic factor, a protein produced in the stomach that is necessary for the absorption of vitamin B12 in the digestive system. Vitamin A, Vitamin D, and Vitamin E deficiencies do not lead to pernicious anemia. Vitamin A deficiency can cause night blindness and skin issues, Vitamin D deficiency can lead to rickets or osteomalacia, and Vitamin E deficiency can result in neurological problems and muscle weakness.

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