Nursing Elites

1. What happens when an atom loses an electron?

• A. It forms a molecule.
• B. It gains a positive charge and becomes an ion.
• C. It alters its elemental identity.
• D. No change occurs; it remains neutral.

Correct answer: B

Rationale: When an atom loses an electron, it gains a positive charge and becomes an ion. This occurs because the number of protons in the atom exceeds the number of electrons, leading to a positive charge. Therefore, the atom undergoes a transformation into an ion by losing an electron. Choice A is incorrect because losing an electron does not result in the formation of a molecule, as molecules are made up of bonded atoms. Choice C is incorrect because losing an electron does not change the fundamental identity of the atom; it only changes its charge. Choice D is incorrect because losing an electron causes the atom to become positively charged, altering its neutrality.

2. During embryonic development, most vertebrates exhibit structures called pharyngeal pouches. These pouches eventually develop into different structures in various vertebrate groups, such as the human jaw and inner ear. Pharyngeal pouches are an example of:

• A. Analogous structures with different evolutionary origins but similar functions
• B. Homologous structures with a common evolutionary origin but diverse functions
• C. Vestigial structures that no longer serve a vital function in some organisms
• D. Atavisms, the reappearance of a trait absent in recent generations

Correct answer: B

Rationale: Pharyngeal pouches in vertebrates are an example of homologous structures because they share a common evolutionary origin. Despite developing into different structures in various vertebrate groups, such as the jaw and inner ear in humans, these structures originated from the same ancestral feature. This concept of homology highlights the evolutionary relationship between different species and how structures can be modified over time to serve different functions while retaining a common origin. Choice A is incorrect because analogous structures have similar functions but different evolutionary origins, which does not apply to pharyngeal pouches. Choice C is incorrect as vestigial structures are remnants of features that were functional in ancestors but have reduced or lost their original function, which is not the case for pharyngeal pouches. Choice D is incorrect because atavisms refer to the reappearance of traits absent in recent generations, which is not the characteristic of pharyngeal pouches.

3. What is the term for the maximum amount of solute that can dissolve in a solvent at a specific temperature and pressure?

• A. Molarity
• B. Solubility
• C. Concentration
• D. Saturation

Correct answer: B

Rationale: Solubility is the correct term for the maximum amount of solute that can dissolve in a solvent at a specific temperature and pressure. Molarity is a measure of concentration, not the maximum amount that can dissolve. Concentration is a general term for the amount of solute present in a given amount of solvent. Saturation is related to solubility but specifically refers to a state where no more solute can be dissolved in the solvent.

4. Which of the following is NOT a function of the forebrain?

• A. To regulate blood pressure and heart rate
• B. To perceive and interpret emotional responses like fear and anger
• C. To perceive and interpret visual input from the eyes
• D. To integrate voluntary movement

Correct answer: A

Rationale: The correct answer is A. The forebrain is primarily responsible for higher cognitive functions such as perception, interpretation, and integration of sensory information, emotional responses, and voluntary movements. Functions like regulating blood pressure and heart rate are mainly controlled by various structures in the brainstem, such as the medulla oblongata and the pons. Choices B, C, and D are all functions associated with the forebrain. Choice B relates to the limbic system, which is part of the forebrain responsible for emotional responses. Choice C corresponds to the occipital lobe in the forebrain, involved in processing visual information. Choice D involves the motor cortex and other areas in the forebrain that coordinate voluntary movements.

5. Which radioactive isotope is commonly used in medical imaging techniques such as PET scans?

• A. Uranium-235
• B. Plutonium-239
• C. Potassium-40
• D. Fluorine-18

Correct answer: D

Rationale: Fluorine-18 is the radioactive isotope commonly used in medical imaging techniques such as PET scans. It is frequently used in the form of fluorodeoxyglucose (FDG) to locate areas of heightened metabolic activity in the body, such as in cancer cells. Uranium-235 and Plutonium-239 are not typically employed in medical imaging, and Potassium-40, while a naturally occurring radioactive isotope found in the human body, is not commonly used in medical imaging techniques.

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