Nursing Elites

1. How does the acceleration of an object change if the force acting on it is doubled?

• A. Acceleration is halved
• B. Acceleration doubles
• C. Acceleration remains unchanged
• D. Acceleration quadruples

Correct answer: B

Rationale: According to Newton's second law of motion, acceleration is directly proportional to the force acting on an object. When the force acting on an object is doubled, the acceleration of the object will also double. This relationship is described by the formula F = ma, where F is the force applied, m is the mass of the object, and a is the acceleration. Therefore, an increase in force will result in a proportional increase in acceleration. Choice A is incorrect because acceleration does not halve but doubles when force doubles. Choice C is incorrect as acceleration changes in direct proportion to force. Choice D is incorrect as acceleration does not quadruple but doubles when force doubles.

2. When human cells divide by meiosis, how many chromosomes do the resulting cells contain?

• A. 96
• B. 54
• C. 46
• D. 23

Correct answer: D

Rationale: When human cells divide by meiosis, the resulting cells contain 23 chromosomes. This is because meiosis is a cell division process that reduces the chromosome number by half, resulting in cells with a haploid number of chromosomes. In humans, the diploid number of chromosomes is 46. Therefore, after meiosis, the resulting cells have 23 chromosomes, ensuring the correct chromosome number is restored upon fertilization. Choices A, B, and C are incorrect as they do not represent the correct chromosome number resulting from meiosis in human cells.

3. 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.

4. Which organ system is most responsible for maintaining control of body temperature?

• A. The skeletal system.
• B. The circulatory system.
• C. The immune system.
• D. The muscular system.

Correct answer: B

Rationale: The circulatory system is the correct answer as it plays a crucial role in maintaining control of body temperature through a process called thermoregulation. Blood vessels near the skin surface dilate to dissipate heat when the body is too warm and constrict to reduce heat loss when it's too cold. Additionally, the circulatory system helps distribute heat produced from metabolic processes throughout the body to keep a stable internal temperature. The skeletal system provides structural support, the immune system defends against pathogens, and the muscular system is responsible for movement, but they are not primarily involved in regulating body temperature.

5. What defines the systole phase in the cardiac cycle?

• A. Relaxation of the heart
• B. Contraction of the heart
• C. Diastole of the heart
• D. Pulse rate of the heart

Correct answer: B

Rationale: The correct answer is B: Contraction of the heart. Systole is the phase of the cardiac cycle during which the heart muscle contracts, pumping blood out of the chambers. It is essential for maintaining circulation and delivering oxygen and nutrients to the body's tissues. Diastole (choice C) is the relaxation phase of the heart when the chambers fill with blood. Pulse rate (choice D) is the number of heartbeats per minute, not specifically related to the systole phase. Choice A, 'Relaxation of the heart,' is incorrect because systole refers to the contraction phase of the cardiac cycle, not relaxation.

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