Nursing Elites

1. Which of the following basic mechanisms of evolution is described as the process where organisms with an advantageous trait survive more often and produce more offspring than organisms without the advantageous trait?

• A. gene flow
• B. genetic drift
• C. mutation
• D. natural selection

Correct answer: D

Rationale: Natural selection is the basic mechanism of evolution that explains how organisms with advantageous traits are more likely to survive and reproduce in a given environment. This leads to the passing on of these favorable traits to their offspring, causing these traits to become more common in the population over time, resulting in evolutionary change. Natural selection is driven by environmental pressures that support the survival and reproduction of individuals with specific traits. Gene flow refers to the movement of genes between populations, genetic drift is the change in allele frequencies due to random events, and mutation is the source of genetic variation but is not the process by which advantageous traits become more prevalent in a population.

2. The adaptive immune system has two main branches: humoral and cell-mediated immunity. Which type of immune cell is primarily responsible for antibody production?

• A. Helper T cells
• B. Cytotoxic T cells
• C. B cells
• D. Natural killer cells

Correct answer: C

Rationale: B cells are primarily responsible for antibody production in the adaptive immune system. When activated, B cells differentiate into plasma cells, which are specialized to produce antibodies. Helper T cells play a crucial role in activating B cells, but they do not directly produce antibodies. Cytotoxic T cells are involved in cell-mediated immunity by killing infected cells, while natural killer cells are part of the innate immune system and target virus-infected and cancerous cells. Therefore, the correct answer is C (B cells) as they are directly involved in the production of antibodies, essential for humoral immunity.

3. What is the common name for the organic compound CH₃OH?

• A. Methane
• B. Ethanol
• C. Methanol
• D. Butanol

Correct answer: C

Rationale: The common name for the organic compound CH₃OH is methanol. Methane (A) has the chemical formula CH₄. Ethanol (B) corresponds to the formula C₂H₅OH. Butanol (D) is a compound with the formula C₄H₉OH. The correct answer is C - Methanol, which is the common name for CH₃OH, while the other options correspond to different organic compounds with distinct formulas. Therefore, methanol is the correct choice when identifying the common name for the compound CH₃OH.

4. What happens to the kinetic energy of an object when its mass is doubled?

• A. Kinetic energy remains the same
• B. Kinetic energy halves
• C. Kinetic energy doubles
• D. Kinetic energy quadruples

Correct answer: A

Rationale: The correct answer is that the kinetic energy remains the same. Kinetic energy is directly proportional to the mass of an object and the square of its velocity. When the mass is doubled, the kinetic energy would increase if the velocity remains constant. However, in this question, only the mass is mentioned, not the velocity. Therefore, when the mass is doubled, the kinetic energy remains the same as long as the velocity remains constant. Choices B, C, and D are incorrect because they incorrectly suggest changes in kinetic energy that do not accurately reflect the relationship between mass and kinetic energy described in the question.

5. Which structure allows for the selective passage of materials into and out of the cell?

• A. DNA
• B. Protein
• C. Carbohydrate
• D. Phospholipid bilayer

Correct answer: D

Rationale: The phospholipid bilayer is a crucial component of the cell membrane, surrounding the cell and regulating the passage of materials into and out of the cell. Its structure enables it to be selectively permeable, controlling which substances can pass through. DNA, proteins, and carbohydrates are essential molecules in the cell but do not directly govern the passage of materials like the phospholipid bilayer does. Therefore, the correct answer is the phospholipid bilayer.

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