Nursing Elites

1. Which element is used in fire extinguishers to smother flames by displacing oxygen?

• A. Nitrogen
• B. Carbon dioxide
• C. Helium
• D. Argon

Correct answer: B

Rationale: Carbon dioxide is the correct answer. It is used in fire extinguishers because it displaces oxygen, which is necessary for combustion. When carbon dioxide is released onto a fire, it reduces the oxygen concentration around the flames, effectively smothering the fire. This disruption of oxygen availability interrupts the chemical reaction that sustains the fire. Nitrogen (Choice A), helium (Choice C), and argon (Choice D) are not typically used in fire extinguishers for smothering flames by displacing oxygen. Nitrogen is an inert gas that can displace oxygen but is not as effective as carbon dioxide in fire suppression.

2. Which type of RNA carries the genetic code from DNA to ribosomes?

• A. Ribosomal RNA (rRNA)
• B. Transfer RNA (tRNA)
• C. Messenger RNA (mRNA)
• D. Deoxyribonucleic acid (DNA)

Correct answer: C

Rationale: - Messenger RNA (mRNA) carries the genetic information from DNA in the cell's nucleus to the ribosomes in the cytoplasm, where protein synthesis occurs. - Ribosomal RNA (rRNA) is a component of the ribosomes where protein synthesis takes place. - Transfer RNA (tRNA) is responsible for bringing amino acids to the ribosomes during protein synthesis. - Deoxyribonucleic acid (DNA) is the genetic material that contains the instructions for building and maintaining an organism. DNA is transcribed into mRNA before being translated into proteins.

3. Which of the following inventions likely had the greatest impact on combating nutrition deficiencies in developing countries?

• A. Food products fortified with dietary vitamins and minerals
• B. Integrated statistical models of fish populations
• C. Advances enabling microscopes to use thicker tissue samples
• D. Refrigerated train cars for transportation of food

Correct answer: A

Rationale: Food products fortified with dietary vitamins and minerals have had the greatest impact on combating nutrition deficiencies in developing countries. By fortifying food products with essential nutrients such as vitamins and minerals, it becomes easier to address specific deficiencies in populations that may not have access to a diverse range of foods. This innovation has been particularly impactful in addressing common deficiencies like vitamin A, iron, zinc, and folic acid, improving overall health outcomes in populations with limited access to nutrient-rich foods. Choices B, C, and D are incorrect. Integrated statistical models of fish populations, advances in microscopy, and refrigerated train cars, while important in their own right, do not directly address combating nutrition deficiencies in developing countries as effectively as food fortification with essential nutrients.

4. How did life most likely arise on Earth?

• A. From simple organic molecules in a primordial soup
• B. By spontaneous generation from non-living matter
• C. Through the arrival of extraterrestrial life forms
• D. We still don't know for sure

Correct answer: A

Rationale: The most widely accepted scientific theory for the origin of life on Earth is abiogenesis, which suggests that life arose from simple organic molecules in a primordial soup. This theory is supported by experiments such as the Miller-Urey experiment, which demonstrated that the basic building blocks of life could have formed under early Earth conditions. While there are other hypotheses and ongoing research in this field, the primordial soup theory is currently the most plausible explanation for the origin of life on Earth. Option B, spontaneous generation from non-living matter, has been disproven and is not considered a valid explanation. Option C, the arrival of extraterrestrial life forms, lacks evidence and is not a widely accepted theory. Option D, stating that we still don't know for sure, is true to some extent as the origin of life is a complex topic, but current scientific understanding leans towards abiogenesis from simple organic molecules in a primordial soup.

5. According to Newton's third law of motion, if you push against a wall with a certain force, the wall will push back with:

• A. A smaller force
• B. An equal force
• C. A greater force
• D. No force at all

Correct answer: B

Rationale: According to Newton's third law of motion, for every action, there is an equal and opposite reaction. When you push against a wall with a certain force, the wall will push back on you with an equal force in the opposite direction. Choice A is incorrect because the wall exerts an equal force back. Choice C is incorrect as it suggests a greater force, which goes against Newton's third law. Choice D is incorrect as the wall does exert a force back in response to your push.

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