Nursing Elites

1. Which of the following is a component of the immune system?

• A. Red blood cells
• B. White blood cells
• C. Platelets
• D. Plasma

Correct answer: B

Rationale: White blood cells are a crucial component of the immune system as they play a key role in fighting infections and foreign invaders. Red blood cells are primarily involved in oxygen transport, platelets are important for blood clotting, and plasma is the liquid component of blood that carries various substances but is not directly involved in the immune response.

2. What is the difference between DNA and RNA?

• A. Both are double-stranded.
• B. DNA contains deoxyribose sugar, while RNA contains ribose sugar.
• C. RNA contains the nitrogenous base uracil, while DNA contains thymine.
• D. Both are identical molecules.

Correct answer: B

Rationale: A) Incorrect. DNA is double-stranded, but RNA is typically single-stranded. B) Correct. DNA contains deoxyribose sugar, which lacks an oxygen atom on the 2' carbon of the sugar ring, while RNA contains ribose sugar, which has an additional hydroxyl group on the 2' carbon. C) Incorrect. RNA contains the nitrogenous base uracil, while DNA contains thymine. D) Incorrect. DNA and RNA have distinct structures and functions, so they are not identical molecules.

3. Which statement correctly matches the valve with its function in the heart?

• A. The aortic valve allows oxygenated blood to flow from the left ventricle to the rest of the body.
• B. The mitral valve opens to allow blood flow from the left atrium to the left ventricle.
• C. The pulmonic valve allows deoxygenated blood to flow from the right ventricle to the pulmonary artery.
• D. The tricuspid valve allows deoxygenated blood to flow from the right atrium to the right ventricle.

Correct answer: A

Rationale: The correct answer is A. The aortic valve allows oxygenated blood to flow from the left ventricle to the rest of the body. When the left ventricle contracts, the aortic valve opens to allow blood to be pumped into the aorta, the body's main artery that carries oxygen-rich blood to various parts of the body. Choices B, C, and D are incorrect because they do not match the described functions of the mitral, pulmonic, and tricuspid valves, respectively. The mitral valve controls the flow of blood between the left atrium and left ventricle, the pulmonic valve regulates the flow of blood from the right ventricle to the pulmonary artery, and the tricuspid valve manages the blood flow between the right atrium and right ventricle.

4. When you push a book across a table, the book experiences an equal and opposite force from the table. Why doesn't the table move as well?

• A. The table is much heavier than the book.
• B. The force on the book acts in a different direction.
• C. The table has a much larger surface area, distributing the force over a wider area.
• D. All of the above

Correct answer: A

Rationale: The table is much heavier than the book, so it requires a much larger force to accelerate it. The book is lighter and easier to move, so the force applied to it causes it to move without significantly affecting the table due to the table's greater mass. Newton's third law states that for every action, there is an equal and opposite reaction. In this case, the force exerted on the book by the table is countered by an equal force exerted on the table by the book, but the table's greater mass resists movement. Choice B is incorrect because the forces are equal and opposite, acting in the same direction. Choice C is incorrect as the surface area does not affect the movement of the table in this scenario. Therefore, the correct answer is A, as the table's greater mass prevents it from moving easily when a force is applied.

5. 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.

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