Nursing Elites

1. Which of the following numbers is the greatest common factor (GCF) of 12 and 18?

• A. 2
• B. 3
• C. 6
• D. 9

Correct answer: C

Rationale: The GCF is the largest number that is a factor of both 12 and 18. We can factor each number to find common factors: 12 = 2 x 2 x 3 and 18 = 2 x 3 x 3. The greatest common factor that appears in both factorizations is 6 (2 x 3).

2. The term that refers to the specific role and position an organism occupies within an ecosystem is called a:

• A. Habitat
• B. Niche
• C. Population
• D. Biome

Correct answer: B

Rationale: Rationale: A) Habitat refers to the specific physical environment where an organism lives, including the biotic and abiotic factors present. While the habitat is important for an organism's survival, it does not encompass the specific role and interactions of the organism within the ecosystem. B) Niche refers to the specific role and position an organism occupies within an ecosystem, including its interactions with other organisms and its physical environment. This includes the organism's feeding habits, behavior, preferred habitat, and how it obtains resources. The niche of an organism is crucial in determining its impact on the ecosystem and its relationships with other species. C) Population refers to a group of individuals of the same species living in a specific area and interacting with each other. While populations play a role in ecosystems, they do not specifically describe the role and position of an individual organism within the ecosystem. D) Biome refers to a large geog

3. After exposure to a pathogen, the immune system develops memory. What type of immune cell is responsible for this immunological memory?

• A. B cells
• B. T cells (specifically memory T cells)
• C. Phagocytes
• D. Natural killer cells

Correct answer: B

Rationale: The correct answer is A: "B cells." B cells are responsible for generating immunological memory after exposure to a pathogen. When B cells encounter a pathogen, they differentiate into memory B cells, which can quickly recognize and respond to the pathogen upon subsequent exposure. These memory B cells are crucial for mounting a faster and more effective immune response, leading to a quicker clearance of the pathogen. T cells, phagocytes, and natural killer cells play important roles in the immune response, but specifically, memory B cells are responsible for immunological memory.

4. Acne vulgaris, commonly known as acne, is primarily caused by

• A. Dry skin (Dry skin can worsen acne but isn't the primary cause)
• B. Clogged pores and excess oil production
• C. Bacterial infection alone (Bacteria play a role but not the sole cause)
• D. Vitamin deficiency

Correct answer: B

Rationale: The correct answer is B: 'Clogged pores and excess oil production.' Acne vulgaris, or acne, is primarily caused by a combination of factors including excess sebum (oil) production by the skin's sebaceous glands and the accumulation of dead skin cells, leading to clogged pores. This environment provides a breeding ground for acne-causing bacteria, contributing to inflammation and the formation of pimples. While factors like dry skin, bacterial infections, and even vitamin deficiencies can exacerbate acne, they are not the primary cause. Thus, B is the most accurate option for the primary cause of acne.

5. A balanced chemical equation for the reaction between sodium and chlorine to form sodium chloride is:

• A. Na + Cl2 -> NaCl
• B. 2Na + Cl2 -> 2NaCl
• C. Na2 + Cl -> 2NaCl
• D. Na + 2Cl -> NaCl2

Correct answer: A

Rationale: The correct balanced chemical equation for the reaction between sodium and chlorine to form sodium chloride is '2Na + Cl2 -> 2NaCl'. This equation is balanced as it shows that 2 atoms of sodium react with 1 molecule of chlorine gas to produce 2 molecules of sodium chloride. Option A 'Na + Cl2 -> NaCl' is incorrect as it does not balance the number of atoms on both sides of the equation. It only shows 1 atom of sodium reacting with 1 molecule of chlorine, which is not a balanced representation of the chemical reaction. Therefore, option B is the correct choice for this question.

6. Which of the following is NOT a type of chemical bond?

• A. Ionic bond
• B. Covalent bond
• C. Metallic bond
• D. Gravitational bond

Correct answer: D

Rationale: Although gravity exists, it's not considered a chemical bond responsible for holding atoms together within molecules.

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