Nursing Elites

1. What is the stage of mitosis during which the nuclear envelope reforms?

• A. Prophase
• B. Metaphase
• C. Telophase
• D. Cytokinesis

Correct answer: C

Rationale: During telophase, the nuclear envelope reforms around the separated sister chromatids at opposite poles of the cell. This stage marks the reversal of the processes that occurred during prophase, where the nuclear envelope breaks down. Metaphase is characterized by the alignment of chromosomes along the metaphase plate in the cell's center. Cytokinesis is the final step of cell division involving cytoplasmic division to form two daughter cells, but it does not involve the reformation of the nuclear envelope. Therefore, choice C (Telophase) is the correct answer as it specifically involves the reformation of the nuclear envelope, distinguishing it from the other stages of mitosis.

2. Which of the following organs is NOT part of the circulatory system?

• A. Kidneys
• B. Heart
• C. Blood
• D. Blood vessels

Correct answer: A

Rationale: The correct answer is A: Kidneys. The kidneys are not part of the circulatory system. While the circulatory system includes the heart, blood, and blood vessels (arteries, veins, capillaries), the kidneys belong to the urinary system. The kidneys are responsible for filtering waste products from the blood and producing urine. Choice B, the heart, is a vital organ in the circulatory system responsible for pumping blood. Choice C, blood, is a key component of the circulatory system that carries oxygen and nutrients to the body's tissues. Choice D, blood vessels (arteries, veins, capillaries), facilitate the circulation of blood throughout the body, playing a crucial role in the circulatory system.

3. Which of the following cations is found at the center of a heme?

• A. Cr (III)
• B. Cu (II)
• C. Iron (II)
• D. Iron (III)

Correct answer: C

Rationale: The correct answer is Iron (II) (Fe2+), which is the cation found at the center of a heme group. Heme contains an iron (II) ion that is coordinated within the porphyrin ring structure. This iron ion is crucial for the function of heme in binding and transporting oxygen in hemoglobin and myoglobin. Choice A (Cr (III)) is incorrect as chromium is not typically found at the center of a heme group. Choice B (Cu (II)) is incorrect as copper is not the cation typically present in heme. Choice D (Iron (III)) is also incorrect as heme predominantly contains iron (II) at its center, not iron (III).

4. What is the momentum of a car with a mass of 1500 kg moving at a speed of 20 m/s?

• A. 30,000 kg m/s
• B. 1500 kg m/s
• C. 20 kg m/s
• D. Momentum cannot be determined without knowing the direction of motion.

Correct answer: A

Rationale: The momentum of an object is calculated by multiplying its mass by its velocity. In this case, the momentum of the car can be determined using the formula momentum = mass x velocity. Substituting the given values, momentum = 1500 kg x 20 m/s = 30,000 kg m/s. Therefore, the correct answer is A, 30,000 kg m/s. Choice B (1500 kg m/s) is incorrect because that value represents the mass of the car, not its momentum. Choice C (20 kg m/s) is incorrect as it only represents the speed of the car, not its momentum. Choice D (Momentum cannot be determined without knowing the direction of motion) is incorrect because momentum is a vector quantity and can be determined using magnitude and direction, but in this case, only the magnitude is required.

5. A light ray travels from air (refractive index 1.00) into water (refractive index 1.33). What happens to its speed and direction?

• A. Speed increases, direction bends towards the normal.
• B. Speed increases, direction bends away from the normal.
• C. Speed decreases, direction bends towards the normal.
• D. Speed and direction remain unchanged.

Correct answer: C

Rationale: When a light ray travels from air (lower refractive index) to water (higher refractive index), its speed decreases due to the change in the medium. This is because light travels slower in denser mediums. As the light ray enters the denser medium, water in this case, it bends towards the normal (the line perpendicular to the surface of the water). This phenomenon is known as refraction. Choice A is incorrect as the speed of light decreases when entering a denser medium. Choice B is incorrect as the direction bends towards the normal, not away from it. Choice D is incorrect as the speed and direction of the light ray do change when moving from air to water.

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