Nursing Elites

1. What is the valve that prevents blood from flowing back from the left ventricle into the left atrium?

• A. Tricuspid valve
• B. Mitral valve
• C. Aortic valve
• D. Pulmonic valve

Correct answer: B

Rationale: The correct answer is B: Mitral valve. The mitral valve, also known as the bicuspid valve, is located between the left atrium and the left ventricle. Its primary function is to prevent the backflow of blood from the left ventricle into the left atrium during ventricular contraction. The tricuspid valve is located between the right atrium and right ventricle, the aortic valve is located between the left ventricle and the aorta, and the pulmonic valve is located between the right ventricle and the pulmonary artery. Therefore, the mitral valve is specifically responsible for preventing backflow in the left side of the heart, making it the correct answer.

2. What is the Doppler effect, and how does it explain the shift in frequency of sound waves perceived by an observer?

• A. It only affects light waves, not sound waves.
• B. It's the change in wave speed due to medium density.
• C. It's the perceived change in frequency due to relative motion.
• D. It's the bending of waves due to different mediums.

Correct answer: C

Rationale: The Doppler effect describes how the perceived frequency of a wave changes depending on the relative motion between the source and observer. For example, an approaching siren sounds higher pitched due to compressed wavefronts, while a receding siren sounds lower due to stretched wavefronts.

3. What is the main function of dietary fiber in the digestive system?

• A. To provide energy
• B. To break down fats
• C. To promote gut bacteria growth
• D. To aid in absorption of nutrients

Correct answer: C

Rationale: Rationale: Dietary fiber refers to the indigestible portion of plant foods that passes relatively intact through the digestive system. While fiber does not provide energy directly to the body, it plays a crucial role in promoting the growth of beneficial gut bacteria. These bacteria help in the fermentation of fiber, producing short-chain fatty acids that can be used as an energy source by the body. Additionally, fiber helps regulate bowel movements, maintain gut health, and support overall digestive function. Therefore, the main function of dietary fiber in the digestive system is to promote gut bacteria growth.

4. In meiosis I, how are sister chromatids distinguished from homologous chromosomes?

• A. Sister chromatids share the same centromere, while homologues have different centromeres.
• B. Sister chromatids have identical DNA sequences, while homologues have slightly different sequences due to crossing over.
• C. Sister chromatids repel each other, while homologues attract each other during synapsis.
• D. Sister chromatids separate during anaphase I, while homologues separate during anaphase II.

Correct answer: B

Rationale: While sister chromatids are identical copies of the same chromosome, homologous chromosomes are paired copies, each inherited from one parent. Crossing over during meiosis I can lead to slight differences in their DNA sequences.

5. A lab report shows a potassium level of 4.5 millimoles per liter (mmol/L). Is this within the normal range of 3.5 to 5.3 mmol/L?

• A. No, it is too low.
• B. Yes, it is within the normal range.
• C. No, it is too high.
• D. Cannot be determined without additional information.

Correct answer: B

Rationale: The potassium level of 4.5 mmol/L falls within the normal range provided (3.5 to 5.3 mmol/L). 5. An infant's feeding schedule prescribes 120 milliliters of formula every 3 hours. How many ounces of formula should be prepared for a 24-hour period?

6. Which element is a critical component of DNA and RNA, essential for storing and transmitting genetic information?

• A. Oxygen
• B. Carbon
• C. Nitrogen
• D. Hydrogen

Correct answer: B

Rationale: Carbon's ability to form diverse bonds makes it the backbone of genetic molecules, enabling efficient information storage and transmission

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