Nursing Elites

1. What is the formula for calculating molarity?

• A. M = n/V
• B. M = n/L
• C. M = mol/L
• D. M = mol/dm³

Correct answer: A

Rationale: The correct formula for calculating molarity is M = n/V. In this formula, 'M' represents molarity, 'n' represents the number of moles of solute, and 'V' represents the volume of the solution in liters. Molarity is defined as the number of moles of solute per liter of solution, hence the ratio of moles to volume. Choice B, 'M = n/L', is incorrect because 'L' should represent liters instead of the number of moles. Choice C, 'M = mol/L', is incorrect as it does not include the representation of the number of moles 'n'. Choice D, 'M = mol/dm³', is incorrect because 'dm³' is a volume unit equal to a liter, but the correct representation should be in terms of the volume of the solution in liters. Therefore, the correct answer is M = n/V.

2. Which structure in the body is responsible for producing testosterone?

• A. Adrenal glands
• B. Pituitary gland
• C. Testes
• D. Pancreas

Correct answer: C

Rationale: The correct answer is C: Testes. The testes are responsible for producing testosterone, the hormone that plays a crucial role in male secondary sexual characteristics such as facial hair, deepening of the voice, and muscle development. The adrenal glands primarily produce cortisol and aldosterone, not testosterone. The pituitary gland regulates hormone production in various glands, including the testes, but it does not directly produce testosterone. The pancreas is responsible for producing insulin and glucagon to regulate blood sugar levels, not testosterone.

3. What is the difference between isometric and isotonic muscle contractions?

• A. Isometric involves movement, while isotonic does not.
• B. Isotonic involves shortening of muscle, while isometric maintains length.
• C. Isometric uses more energy, while isotonic uses less.
• D. Isotonic involves smooth muscle, while isometric involves skeletal muscle.

Correct answer: B

Rationale: The correct answer is B. Isometric contractions occur when the muscle generates tension without changing its length, while isotonic contractions involve the muscle changing length to move a load. In isotonic contractions, the muscle shortens to move a load, whereas in isometric contractions, the muscle contracts to hold a position without movement. Choice A is incorrect because isometric contractions do not involve movement, while choice C is incorrect as isotonic contractions typically require more energy due to movement. Choice D is incorrect because the type of muscle involved (smooth or skeletal) is not the defining factor between isometric and isotonic contractions.

4. In the 18th century, women were more likely to die in childbirth compared to the 21st century. What is a possible explanation for why women are less likely to die in childbirth in the present age?

• A. Doctors are better equipped to perform cesarean sections.
• B. Doctors have more tools to monitor mothers during childbirth, enabling earlier detection of complications.
• C. Doctors practice good hand hygiene to prevent the transfer of germs and infections.
• D. All of the statements above provide reasonable explanations for the decrease in mortality during childbirth.

Correct answer: D

Rationale: All options are valid explanations for the decrease in maternal mortality during childbirth in modern times. Improved medical knowledge and technology have enabled doctors to perform cesarean sections more effectively, monitor mothers more closely for early detection of complications, and maintain better hygiene practices to reduce the risk of infections. Therefore, all the given statements collectively contribute to the reduction in maternal mortality rates in the 21st century.

5. What happens to the density of a substance if its mass increases while its volume remains constant?

• A. Density increases
• B. Density decreases
• C. Density remains constant
• D. Density becomes zero

Correct answer: A

Rationale: When the mass of a substance increases while its volume remains constant, the density, which is calculated by dividing mass by volume, will increase. This is because with a higher mass and the volume staying the same, the ratio of mass to volume (density) will be greater, resulting in an overall increase in density. Choice B, 'Density decreases,' is incorrect because an increase in mass with constant volume leads to a higher density. Choice C, 'Density remains constant,' is incorrect as an increase in mass will cause the density to increase. Choice D, 'Density becomes zero,' is incorrect because even with an increase in mass, as long as volume remains constant, density will not reach zero; it will increase instead.

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