Nursing Elites

1. Peppered moths in England came in two color variations – light and dark. After the Industrial Revolution, the population shifted towards more dark moths. This is an example of:

• A. Artificial selection (humans breeding for desired traits)
• B. Natural selection acting on pre-existing variation
• C. Punctuated equilibrium (rapid bursts of evolution)
• D. Lamarckism (inheritance of acquired characteristics)

Correct answer: B

Rationale: Rationale: The phenomenon of peppered moths in England shifting towards more dark moths after the Industrial Revolution is a classic example of natural selection acting on pre-existing variation. Before the Industrial Revolution, light-colored moths were better camouflaged against lichen-covered tree trunks, which were common in the environment. However, with the increase in industrial pollution, the tree trunks became darker due to soot, making dark-colored moths better camouflaged and less likely to be eaten by predators. As a result, the population shifted towards more dark moths over time. This change in the moth population was driven by the selective pressure of predation, demonstrating the process of natural selection favoring individuals with traits that provide a survival advantage in a changing environment.

2. What is the process of making copies of RNA from DNA called?

• A. Replication
• B. Transcription
• C. Translation
• D. DNA repair

Correct answer: B

Rationale: Rationale: Transcription is the process of making copies of RNA from DNA. During transcription, the enzyme RNA polymerase binds to a specific region of DNA and synthesizes a complementary RNA strand based on the DNA template. This process is essential for gene expression and protein synthesis in cells. Replication (option A) refers to the process of making copies of DNA, not RNA. Translation (option C) is the process of synthesizing proteins from mRNA, not making copies of RNA from DNA. DNA repair (option D) involves mechanisms that cells use to repair damaged DNA, not the process of making RNA copies from DNA.

3. The T wave on an ECG corresponds to:

• A. Atrial depolarization
• B. Ventricular depolarization
• C. Atrial repolarization
• D. Ventricular repolarization

Correct answer: D

Rationale: The T wave on an ECG corresponds to ventricular repolarization. During this phase, the ventricles are resetting electrically after contraction, preparing for the next heartbeat. Atrial depolarization is represented by the P wave, ventricular depolarization by the QRS complex, and atrial repolarization is typically hidden within the QRS complex. Therefore, option D, 'Ventricular repolarization,' is the correct choice when identifying the electrical activity represented by the T wave on an ECG.

4. Which of the following minerals is important for bone health and is stored in bones by the skeletal system?

• A. Iron
• B. Sodium
• C. Calcium
• D. Magnesium

Correct answer: C

Rationale: The correct answer is C: Calcium. Calcium is essential for maintaining strong and healthy bones. It is a key mineral stored in bones by the skeletal system, where it provides structural support and strength. Adequate calcium intake is crucial for preventing bone diseases like osteoporosis and ensuring proper bone formation and density. Iron (A), Sodium (B), and Magnesium (D) are important minerals for various bodily functions but are not primarily responsible for bone health and storage in bones by the skeletal system.

5. Which of the following organelles is responsible for the production of proteins in the cell?

• A. Ribosomes
• B. Golgi apparatus
• C. Mitochondria
• D. Lysosomes

Correct answer: A

Rationale: The correct answer is A: Ribosomes. Ribosomes are the organelles responsible for protein synthesis in the cell. They are found in both prokaryotic and eukaryotic cells and can be free-floating in the cytoplasm or attached to the endoplasmic reticulum. Ribosomes read the messenger RNA (mRNA) and translate the genetic code into proteins through a process called translation. The Golgi apparatus is involved in processing and packaging proteins for secretion, while mitochondria are responsible for energy production. Lysosomes are involved in digestion and waste removal within the cell.

6. Why are noble gas elements generally unreactive?

• A. They are too large and cannot form bonds easily.
• B. They lack valence electrons in their outermost shell.
• C. They have strong bonds within their own molecules.
• D. They have already achieved stable electron configurations.

Correct answer: D

Rationale: They have already achieved stable electron configurations. With completely filled outermost shells, noble gas elements have no need to gain or lose electrons, minimizing their tendency to participate in chemical reactions.

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