Nursing Elites

1. How does lymph move through the lymphatic vessels?

• A. By the pumping action of the heart
• B. Due to muscle contractions and breathing movements
• C. Through one-way valves within the vessels
• D. All of the above

Correct answer: C

Rationale: Lymph moves through the lymphatic vessels due to the presence of one-way valves within the vessels. These valves prevent the backflow of lymph and help propel the fluid forward as muscles contract and relax or due to breathing movements. Unlike blood circulation, the lymphatic system does not rely on the pumping action of the heart to move lymph. Choice A is incorrect because lymphatic circulation does not depend on the pumping action of the heart. Choice B is partly correct as muscle contractions and breathing movements do assist in propelling lymph, but the primary mechanism is the presence of one-way valves within the vessels, making choice C the most accurate answer. Choice D is incorrect as not all options listed contribute to how lymph moves through the lymphatic vessels.

2. An atom has 2 protons, 4 neutrons, and 2 electrons. What is the approximate atomic mass of this atom?

• A. 2
• B. 4
• C. 6
• D. 8

Correct answer: D

Rationale: The atomic mass of an atom is the sum of the protons and neutrons in its nucleus. In this case, the atom has 2 protons and 4 neutrons, totaling 6 particles in the nucleus. Therefore, the approximate atomic mass of this atom is 6, making choice C incorrect. The number of electrons does not significantly contribute to the atomic mass, as they are much lighter and located in the electron cloud surrounding the nucleus. Choices A, B, and C are incorrect as they do not reflect the correct calculation of atomic mass based on protons and neutrons only.

3. If the mass of an object remains constant and its velocity doubles, how does its momentum change?

• A. Momentum doubles
• B. Momentum halves
• C. Momentum quadruples
• D. Momentum remains the same

Correct answer: C

Rationale: Momentum is calculated as the product of an object's mass and its velocity. When the mass remains constant and the velocity doubles, the momentum will increase by a factor of 2 (doubling) due to the increase in velocity. Therefore, the momentum will quadruple (2 x 2 = 4) when the velocity doubles. This relationship between momentum and velocity showcases the direct proportionality of momentum to velocity, given a constant mass. Choices A, B, and D are incorrect. Momentum does not simply double or halve when the velocity doubles; it quadruples as it is directly proportional to the velocity. Hence, the correct answer is C, where momentum quadruples in this scenario.

4. What is the difference between a real image and a virtual image formed by a lens?

• A. Real images can be projected onto a screen, while virtual images cannot.
• B. Real images are always upright, while virtual images can be inverted.
• C. Real images are formed by converging lenses, while virtual images are formed by diverging lenses.
• D. All of the above are true.

Correct answer: A

Rationale: The correct answer is A. Real images can be projected onto a screen because they are formed by the actual convergence of light rays, while virtual images cannot be projected onto a screen as they appear to diverge from a point behind the lens. Real and virtual images do not have a consistent orientation (upright or inverted), so option B is incorrect. Real images are formed by both converging and diverging lenses depending on the specific scenario, so option C is not a definitive distinction. Option D is incorrect as not all the statements are true. Therefore, the only accurate general distinction between real and virtual images is that real images can be projected onto a screen, while virtual images cannot.

5. At which of the following ages would ossification most likely take place to replace cartilage at the growth plate?

• A. 5
• B. 18
• C. 42
• D. 91

Correct answer: B

Rationale: Ossification, the process where cartilage is replaced by bone, typically occurs during adolescence, around the age of 18. This is when the growth plates in the bones close, and the bones stop growing in length, leading to the replacement of cartilage with bone tissue. Choice A (5) is incorrect because ossification primarily occurs during adolescence, not early childhood. Choice C (42) is incorrect as ossification is completed well before this age, usually during the late teens or early twenties. Choice D (91) is incorrect as ossification is a process that occurs earlier in life, typically during adolescence, and is not a process that occurs in advanced age.

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