Nursing Elites

1. During antibiotic use, bacteria can evolve resistance. This is an example of:

• A. Coevolution (two species influencing each other's evolution)
• B. Convergent evolution (unrelated organisms evolving similar traits)
• C. Macroevolution (large-scale evolutionary change)
• D. Artificial selection acting on a natural process

Correct answer: D

Rationale: Rationale: - Coevolution (option A) refers to the influence of two species on each other's evolution, which is not the case in the scenario described in the question. - Convergent evolution (option B) involves unrelated organisms evolving similar traits due to similar environmental pressures, which is not directly applicable to the situation of bacteria evolving resistance to antibiotics. - Macroevolution (option C) refers to large-scale evolutionary changes over long periods, which is not specifically demonstrated in the context of bacteria evolving resistance during antibiotic use. - The process of bacteria evolving resistance to antibiotics due to the selective pressure exerted by the antibiotics is an example of artificial selection (human intervention selecting for certain traits) acting on a natural process (bacterial evolution). Antibiotic use creates a selective pressure that favors the survival and reproduction of bacteria with resistance traits, leading to the evolution of an

2. Electrons occupy specific energy levels around the nucleus, but not in fixed orbits. This concept is captured by the:

• A. Bohr model
• B. Quantum mechanical model
• C. Lewis structure
• D. Octet rule

Correct answer: B

Rationale: Quantum mechanical model. Unlike the Bohr model with its defined electron paths, the quantum mechanical model uses probability distributions to describe electron locations within energy levels.

3. What is the general formula for an alkene?

• A. CnH2n+2
• B. CnH2n
• C. CnH2n-2
• D. CnH2n+1

Correct answer: B

Rationale: The general formula for an alkene is \(C_nH_{2n}\), indicating the presence of a double bond between carbon atoms.

4. What is the process of converting DNA into a protein called?

• A. Transcription
• B. Translation
• C. Replication
• D. Mutation

Correct answer: A

Rationale: Transcription is the process of converting DNA into a molecule called messenger RNA (mRNA). This mRNA molecule carries the genetic information from DNA to the ribosomes, where it is used to make proteins.

5. Organisms that break down dead organisms and return nutrients to the environment are called:

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

Correct answer: B

Rationale: Rationale: Decomposers are organisms that break down dead organisms and organic matter, such as bacteria, fungi, and some insects. They play a crucial role in the ecosystem by breaking down complex organic materials into simpler forms, releasing nutrients back into the environment for other organisms to use. Producers (option A) are organisms that produce their own food through photosynthesis, consumers (option C) are organisms that consume other organisms for energy, and parasites (option D) are organisms that live on or in another organism and benefit at the host's expense.

6. 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.

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