Nursing Elites

1. 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 a hormone produced by the pineal gland in the brain and plays a crucial role in regulating the sleep-wake cycle, also known as the circadian rhythm. Melatonin levels typically rise in the evening in response to darkness and help signal to the body that it's time to sleep. Exposure to light, especially blue light, can inhibit the production of melatonin, making us more alert and awake. Cortisol (option B) is a stress hormone that helps regulate metabolism and immune response. Estrogen (option C) is a female sex hormone, and glucagon (option D) is a hormone that increases blood sugar levels. Therefore, the hormone responsible for regulating sleep-wake cycles and influenced by light exposure is melatonin.

2. What is the net ionic equation for the reaction: 2HCl(aq) + Ba(OH)2(aq) → 2H2O(l) + BaCl2(aq)?

• A. 2H+(aq) + 2OH-(aq) → 2H2O(l)
• B. 2HCl(aq) + Ba(OH)2(aq) → BaCl2(aq) + 2H2O(l)
• C. 2H+(aq) + Ba2+(aq) → Ba2+(aq) + 2H+(aq)
• D. Ba(OH)2(aq) + HCl(aq) → BaCl2(aq) + 2H2O(l)

Correct answer: a

Rationale: The net ionic equation includes only the species that undergo a change during the reaction.

3. What is the unit of measurement for density?

• A. Grams per liter (g/L)
• B. Kilograms per cubic meter (kg/m³)
• C. Pounds per square inch (psi)
• D. Newtons per meter (N/m)

Correct answer: A

Rationale: Density is defined as mass per unit volume. The most commonly used unit for density in the metric system is grams per liter (g/L). Kilograms per cubic meter (kg/m³) is also a common unit for density, but grams per liter is more frequently used in everyday measurements. Pounds per square inch (psi) is a unit of pressure, not density. Newtons per meter (N/m) is a unit of force per unit length, not density.

4. What type of force allows a car to take a sharp turn while moving in a circular path?

• A. Centripetal force
• B. Tension force
• C. Frictional force
• D. Gravitational force

Correct answer: A

Rationale: Centripetal force is the force that allows an object to move in a circular path. In the case of a car taking a sharp turn, the centripetal force is directed towards the center of the circle, keeping the car moving in a curved path. Tension force is the force transmitted through a string, rope, cable, or wire when it is pulled tight by forces acting from opposite ends. Frictional force opposes the motion of an object and is not the primary force responsible for allowing a car to take a sharp turn. Gravitational force is the force of attraction between two masses and is not directly related to a car taking a sharp turn.

5. What is the building block of DNA?

• A. Amino acid
• B. Nucleotide
• C. Nucleotide
• D. Fatty acid

Correct answer: B

Rationale: Rationale: - Amino acids are the building blocks of proteins, not DNA. - Nucleotide is the correct building block of DNA. A nucleotide consists of a sugar (deoxyribose in DNA), a phosphate group, and a nitrogenous base (adenine, thymine, cytosine, or guanine). - The option "C) Nucleotide" is a duplicate of the correct answer "B) Nucleotide." - Fatty acids are not the building blocks of DNA; they are a type of lipid molecule.

6. Urine, the liquid waste product of the body, travels from the kidneys to the bladder through tubes called:

• A. Ureters
• B. Urethra
• C. Nephrons
• D. Renal pelvis

Correct answer: A

Rationale: The correct answer is A: Ureters. Ureters are the tubes that connect the kidneys to the bladder, allowing urine to flow from the kidneys to the bladder for storage before elimination. The urethra, option B, is the tube through which urine is expelled from the bladder out of the body. Nephrons, option C, are the functional units of the kidneys responsible for filtering blood and producing urine. The renal pelvis, option D, is a part of the kidney where urine collects before entering the ureters. Therefore, the correct answer is A, as the ureters specifically carry urine from the kidneys to the bladder.

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