Nursing Elites

1. Which of the following is NOT a function of the cilia lining the respiratory tract?

• A. Trapping inhaled dust and debris
• B. Moistening inhaled air
• C. Producing mucus
• D. Propelling mucus upwards towards the throat

Correct answer: C

Rationale: The correct answer is C: 'Producing mucus.' Cilia lining the respiratory tract do not produce mucus, but rather move the mucus that is produced by other cells. The cilia work together to propel the mucus upwards towards the throat, where it can be either swallowed or expelled. Trapping inhaled dust and debris, moistening inhaled air, and propelling mucus upwards are all important functions of the cilia in the respiratory tract, helping to protect the lungs and maintain respiratory health.

2. What is the main reason why elements in Group 18 (Noble gases) are generally unreactive?

• A. They have high atomic masses
• B. They lack valence electrons
• C. Their outermost electron shells are completely filled
• D. They exist as single atoms, not molecules

Correct answer: C

Rationale: Noble gases have their outermost electron shells filled with 8 electrons, achieving a stable configuration with minimal urge to gain or lose electrons, making them less prone to chemical reactions.

3. A scientific theory is:

• A. A personal belief or hunch about how something works.
• B. A well-substantiated explanation based on evidence and repeated testing.
• C. A single experiment's findings not yet confirmed by others.
• D. A fixed and unchanging dogma beyond questioning.

Correct answer: B

Rationale: Theories in science are constantly evolving and open to revision as new data emerges, unlike personal beliefs or fixed dogmas.

4. Which type of muscle tissue has a unique branching network and is found in the heart?

• A. Skeletal muscle
• B. Cardiac muscle
• C. Smooth muscle
• D. Multifidus muscle

Correct answer: B

Rationale: The correct answer is B - Cardiac muscle. Cardiac muscle is the type of muscle tissue that has a unique branching network and is specifically found in the heart. Unlike skeletal muscle, which is attached to bones and allows for voluntary movement, cardiac muscle is involuntary and contracts to pump blood throughout the body. Smooth muscle is found in organs like the intestines and blood vessels, while the multifidus muscle is a specific muscle in the back. Therefore, cardiac muscle is the appropriate choice in this scenario.

5. Which muscular pouch in the upper left abdomen stores food after swallowing and begins mechanical and chemical digestion?

• A. Esophagus
• B. Stomach
• C. Small intestine
• D. Large intestine

Correct answer: B

Rationale: The correct answer is B: Stomach. The stomach is the muscular pouch in the upper left abdomen that stores food after swallowing. It is responsible for beginning both mechanical and chemical digestion processes. Once food enters the stomach, it is mixed with gastric juices and enzymes that break down the food into smaller particles. The stomach also contracts and relaxes to further mix the food with digestive juices. The esophagus is a tube that connects the throat to the stomach and does not store food or participate in digestion. The small intestine and large intestine are parts of the digestive system, but they are not muscular pouches in the upper left abdomen responsible for storing and digesting food.

6. What is the role of RNA interference in silencing genes?

• A. Increases protein production
• B. Promotes gene mutation
• C. Inhibits the expression of specific genes
• D. Repairs damaged DNA

Correct answer: C

Rationale: Rationale: RNA interference (RNAi) is a biological process that involves the silencing of gene expression by inhibiting the translation of mRNA or by degrading mRNA molecules. This mechanism plays a crucial role in regulating gene expression and can be used to selectively silence specific genes. By interfering with the expression of specific genes, RNAi can downregulate protein production from those genes. Therefore, option C, "Inhibits the expression of specific genes," is the correct role of RNA interference in silencing genes.

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