Nursing Elites

1. What does the P-wave in an ECG correspond to?

• A. Atrial repolarization
• B. Depolarization of SA node
• C. Ventricular depolarization
• D. Ventricular repolarization

Correct answer: B

Rationale: The P-wave in an ECG represents the depolarization of the SA node and the atria, not atrial repolarization. Choice C, ventricular depolarization, is incorrect because the P-wave does not correspond to ventricular activity. Choice D, ventricular repolarization, is also incorrect as the P-wave does not depict ventricular repolarization. The correct interpretation is that the P-wave signifies the initiation of the electrical impulse at the SA node and subsequent atrial depolarization, making option B the correct answer.

2. During which of the following stages does crossing over occur?

• A. Mitosis Prophase
• B. Meiosis Prophase I
• C. Meiosis Prophase II
• D. Interphase

Correct answer: B

Rationale: Crossing over occurs during Prophase I of meiosis. This stage is specifically associated with genetic recombination, where homologous chromosomes exchange genetic material. This process contributes to genetic diversity by creating new combinations of alleles. Choices A, C, and D are incorrect. In mitosis, crossing over does not occur as it involves the separation of replicated chromosomes. Meiosis Prophase II is focused on the reformation of nuclei and does not involve crossing over. Interphase is a stage where the cell prepares for division and is not associated with crossing over.

3. What is the unit of force in the SI system?

• A. Newton (N)
• B. Kilogram (kg)
• C. Meter (m)
• D. Second (s)

Correct answer: A

Rationale: The unit of force in the SI system is the Newton (N). It is defined as the amount of force required to accelerate a mass of one kilogram at a rate of one meter per second squared. In the SI system, force is measured in Newtons, not in kilograms, meters, or seconds. Choice B, Kilogram (kg), is incorrect because kilograms are units of mass, not force. Choice C, Meter (m), is incorrect because meters are units of length, not force. Choice D, Second (s), is incorrect because seconds are units of time, not force.

4. What is the basic unit of heredity?

• A. Chromosome
• B. Cell
• C. Gene
• D. Organ

Correct answer: C

Rationale: A gene is the basic unit of heredity that carries the instructions for making proteins, which determine an organism's traits. Genes are segments of DNA located on chromosomes within the cell. While chromosomes contain many genes, a gene itself is the fundamental unit of heredity responsible for passing on genetic information from one generation to the next. Cells are the basic structural and functional units of living organisms, but genes specifically carry genetic information. Organs are composed of tissues and serve specific functions within an organism, but they are not the basic unit of heredity.

5. What are organisms that break down dead organisms and return nutrients to the environment called?

• A. Producers
• B. Decomposers
• C. Consumers
• D. Parasites

Correct answer: B

Rationale: Decomposers are essential organisms in the ecosystem as they break down dead organisms and organic matter, such as bacteria, fungi, and some insects. By decomposing complex organic materials into simpler forms, they release nutrients back into the environment for other organisms to utilize. Producers (option A) are organisms that generate their own food through photosynthesis; consumers (option C) are organisms that feed on other organisms for energy, and parasites (option D) are organisms that live on or in another organism, benefiting at the host's expense rather than breaking down dead organisms for nutrient recycling.

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