Nursing Elites

1. Salts like sodium iodide (NaI) and potassium chloride (KCl) use what type of bond?

• A. Ionic bonds
• B. Disulfide bridges
• C. Covalent bonds
• D. London dispersion forces

Correct answer: A

Rationale: Salts like sodium iodide (NaI) and potassium chloride (KCl) use ionic bonds. Ionic bonds are formed between atoms with significantly different electronegativities, leading to the transfer of electrons from one atom to another. In the case of NaI and KCl, sodium (Na) and potassium (K) are metals that easily lose electrons to become positively charged ions, while iodide (I) and chloride (Cl) are nonmetals that readily accept electrons to become negatively charged ions. The attraction between the oppositely charged ions forms the ionic bond, which holds the compound together in a lattice structure. Disulfide bridges (option B) are covalent bonds formed between sulfur atoms in proteins, not in salts. Covalent bonds (option C) involve the sharing of electrons between atoms and are typically seen in molecules, not ionic compounds like salts. London dispersion forces (option D) are weak intermolecular forces that occur between all types of molecules but are not the primary type of bond in salts like NaI and KCl.

2. What is the name of the microscopic finger-like projections that increase the surface area for absorption in the small intestine?

• A. Goblet cells
• B. Paneth cells
• C. Villi
• D. Crypts of Lieberkühn

Correct answer: C

Rationale: A) Goblet cells: Goblet cells are specialized cells that secrete mucus to protect the lining of the digestive tract. While important for maintaining the health of the intestines, goblet cells do not increase the surface area for absorption in the small intestine. B) Paneth cells: Paneth cells are specialized cells found in the small intestine that secrete antimicrobial peptides. They play a role in protecting the intestinal stem cells and maintaining the gut microbiota balance, but they do not increase the surface area for absorption. C) Villi: Villi are microscopic finger-like projections found in the small intestine that increase the surface area available for absorption of nutrients. Each villus contains blood vessels and lacteals (lymphatic vessels) that help absorb nutrients from digested food. D) Crypts of Lieberkühn: Crypts of Lieberkühn are small pits located between the villi

3. Dendrites are finger-like extensions found on

• A. Muscle cells
• B. Connective tissue cells
• C. Neurons
• D. Epithelial cells

Correct answer: C

Rationale: Dendrites are the branched extensions of neurons that receive signals from other neurons and transmit those signals to the cell body. They play a crucial role in the communication process within the nervous system, allowing neurons to communicate with each other and integrate incoming signals to generate responses. The other choices are incorrect because dendrites specifically belong to neurons, not muscle cells, connective tissue cells, or epithelial cells.

4. At the peak of its trajectory, what force is acting on a ball thrown upwards?

• A. Gravity only
• B. Gravity and air resistance only
• C. Neither gravity nor air resistance
• D. All of the above

Correct answer: A

Rationale: At the peak of its trajectory, the ball momentarily stops moving upwards before it starts to fall back down. At this point, the only force acting on the ball is gravity, pulling it back towards the ground. Air resistance is negligible at the peak of the trajectory as the ball is momentarily stationary. Therefore, the correct answer is 'Gravity only.' Choices B, C, and D are incorrect. Option B is incorrect because air resistance is minimal when the ball is at its highest point and its velocity is nearly zero. Option C is incorrect as gravity is the only significant force acting on the ball at that instant. Option D is incorrect since air resistance is not a significant factor at the peak of the trajectory.

5. Which hormone is responsible for regulating sleep-wake cycles and is influenced by light exposure?

• A. Melatonin
• B. Cortisol
• C. Estrogen
• D. Glucagon

Correct answer: A

Rationale: The correct answer is A: Melatonin. Melatonin is the hormone responsible for regulating sleep-wake cycles, also known as the circadian rhythm. Its production is influenced by light exposure, with levels increasing in the evening in response to darkness, signaling the body that it is time to sleep. Choice B, cortisol, is a stress hormone and does not directly regulate sleep-wake cycles. Choice C, estrogen, is a sex hormone and is not primarily involved in regulating sleep. Choice D, glucagon, is a hormone that increases blood glucose levels and is not related to sleep-wake cycles.

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