Nursing Elites

1. Which of the following is a type of white blood cell that plays a key role in adaptive immunity by seeking out, attacking, and destroying targeted pathogens?

• A. memory B cells
• B. neutrophils
• C. antibodies
• D. cytotoxic T cells

Correct answer: D

Rationale: The correct answer is cytotoxic T cells. Cytotoxic T cells are a type of white blood cell that is crucial in adaptive immunity. They are specialized in recognizing and destroying infected or abnormal cells in the body. Neutrophils are primarily involved in innate immunity, providing rapid response to infections. Antibodies are proteins produced by B cells and are essential in specific immune responses, but they do not directly attack pathogens. Memory B cells are part of the adaptive immune response, responsible for mounting a quicker and stronger response upon re-exposure to a pathogen. However, they do not directly seek out and destroy pathogens like cytotoxic T cells do.

2. Which type of reaction is represented by the equation A + B → AB?

• A. Synthesis
• B. Decomposition
• C. Single Replacement
• D. Double Replacement

Correct answer: A

Rationale: The correct answer is 'Synthesis.' In a synthesis reaction, two or more reactants combine to form a single product. The equation A + B → AB represents a synthesis reaction where substances A and B combine to form compound AB. Choice B, 'Decomposition,' involves a single compound breaking down into two or more simpler substances, which is not the case in this equation. Choices C and D, 'Single Replacement' and 'Double Replacement,' involve the replacement of elements in compounds or the exchange of ions between compounds, neither of which is depicted in the given equation. Thus, 'Synthesis' is the most suitable classification for the reaction A + B → AB.

3. In the suburban neighborhood of Northwoods, there has been a large population of deer, and residents have complained about them eating flowers and garden plants. What would be a logical explanation for the large increase in the deer population over the last two seasons?

• A. There has been an increase in the quantity of food sources in surrounding areas.
• B. The population of natural predators in Northwoods has decreased.
• C. Deer have migrated from surrounding areas.
• D. There has been a recent increase in hunting licenses sold.

Correct answer: B

Rationale: The correct answer is B because a decrease in natural predators can lead to an increase in the deer population as there are fewer predators to control their numbers. This explanation aligns with the situation described in the question, where the deer population has increased, causing issues for residents. Choice A is incorrect because an increase in food sources would not directly explain the increase in the deer population. Choice C is incorrect as it introduces a new factor of migration which is not mentioned in the question. Choice D is incorrect as an increase in hunting licenses sold would likely have the opposite effect on the deer population.

4. How many neutrons and electrons could a negative ion of sulfur have?

• A. 16 neutrons, 16 electrons
• B. 16 neutrons, 17 electrons
• C. 17 neutrons, 16 electrons
• D. 17 neutrons, 17 electrons

Correct answer: B

Rationale: A negative ion of sulfur would have 16 protons and 17 electrons since it gains one electron. The number of neutrons in an ion does not change, so the neutrons would remain at 16. Therefore, the correct answer is 16 neutrons and 17 electrons, which corresponds to choice B. Choice A is incorrect as it does not account for the extra electron gained by the negative ion. Choices C and D are incorrect because they propose a change in the number of neutrons, which is not affected by the ionization process.

5. What is a rod-shaped structure that forms when a single DNA molecule and its associated proteins coil tightly before cell division?

• A. Centromere
• B. Chromatid
• C. Chromosome
• D. Gene

Correct answer: C

Rationale: A chromosome is a rod-shaped structure that forms when a single DNA molecule and its associated proteins coil tightly before cell division. It contains the genetic material and is essential for cell division and replication. The centromere is a specific region of a chromosome that plays a role in cell division. A chromatid is one half of a duplicated chromosome, and a gene is a unit of heredity responsible for specific traits. Therefore, the correct answer is 'Chromosome' as it represents the entire condensed DNA molecule during cell division.

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