Nursing Elites

1. What is the main function of calcitonin, a hormone produced by the thyroid gland?

• A. Stimulate metabolism and heat production
• B. Increase calcium absorption from the intestines
• C. Enhance bone growth and development
• D. Lower blood calcium levels

Correct answer: D

Rationale: Calcitonin is a hormone produced by the thyroid gland that primarily functions to lower blood calcium levels. It achieves this by inhibiting bone breakdown and promoting calcium excretion by the kidneys. Therefore, the correct answer is D as it reflects the main role of calcitonin in calcium homeostasis. Choices A, B, and C are incorrect as they do not align with the primary function of calcitonin. Calcitonin does not stimulate metabolism and heat production (Choice A), increase calcium absorption from the intestines (Choice B), or enhance bone growth and development (Choice C).

2. What is the coefficient of oxygen in the balanced chemical equation for the combustion of methane (CH₄)?

• A. 1
• B. 2
• C. 3
• D. 4

Correct answer: B

Rationale: In the balanced chemical equation for the combustion of methane, CH₄ + 2O₂ → CO₂ + 2H₂O, the coefficient of oxygen (O₂) is 2. This indicates that two molecules of oxygen are required to react with one molecule of methane to produce carbon dioxide and water, ensuring the equation is balanced. Choice A is incorrect because the coefficient of oxygen is not 1 but 2. Choices C and D are incorrect as they do not represent the correct coefficient of oxygen in the balanced equation. Understanding the coefficients in a balanced chemical equation is crucial for accurately representing the stoichiometry of the reaction.

3. Which structure in the female reproductive system is responsible for producing eggs (ova)?

• A. Fallopian tubes
• B. Ovaries
• C. Uterus
• D. Vagina

Correct answer: B

Rationale: The correct answer is the ovaries. Ovaries are the primary reproductive organs in females responsible for producing eggs (ova) through a process known as oogenesis. Ova are released from the ovaries during ovulation and can be fertilized by sperm in the fallopian tubes. The uterus is where a fertilized egg implants and develops into a fetus, while the vagina serves as the birth canal and a site for sexual intercourse. Fallopian tubes are responsible for transporting eggs from the ovaries to the uterus and are the site where fertilization typically occurs. Therefore, while important for the reproductive process, the fallopian tubes do not produce eggs.

4. Elements tend to gain or lose electrons to achieve stable electron configurations like those of noble gases. Their group number often indicates the number of electrons gained/lost and the resulting ionic charge, providing a good starting point for prediction.

• A. Ionic bonds involve electron sharing, while metallic bonds involve electron transfer.
• B. Ionic bonds are weak and directional, while metallic bonds are strong and non-directional.
• C. Ionic bonds exist between metals and non-metals, while metallic bonds exist only between metals.
• D. Ionic bonds form discrete molecules, while metallic bonds form extended structures.

Correct answer: C

Rationale: Ionic bonds typically form between metals and non-metals, where one atom donates electrons (cation) and the other accepts electrons (anion). This results in the transfer of electrons. Metallic bonds, on the other hand, occur between metal atoms where electrons are shared among a sea of delocalized electrons, leading to the characteristic properties of metals like malleability and conductivity. Choice A is incorrect because ionic bonds involve electron transfer, not sharing. Choice B is incorrect as ionic bonds are strong, not weak, and are non-directional, while metallic bonds are strong and non-directional. Choice D is incorrect as ionic bonds do not form discrete molecules but rather a lattice structure, whereas metallic bonds form extended structures.

5. Which muscular tube carries urine from the kidneys to the bladder?

• A. Nephron
• B. Ureter
• C. Urethra
• D. Glomerulus

Correct answer: B

Rationale: The correct answer is B: Ureter. The ureter is the muscular tube that carries urine from the kidneys to the bladder. The nephron is the functional unit of the kidney responsible for filtering blood and producing urine. The urethra is the tube that carries urine from the bladder out of the body. The glomerulus is a network of capillaries in the nephron where filtration of blood occurs.

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