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. Which molecule allows for the selective passage of materials into and out of the cell?

• A. DNA
• B. Protein
• C. Carbohydrate
• D. Phospholipid bilayer

Correct answer: D

Rationale: The correct answer is D, the phospholipid bilayer. The phospholipid bilayer is the main component of the cell membrane, which acts as a selective barrier allowing certain molecules to pass through while blocking others. Its structure consists of hydrophilic heads facing outward towards the aqueous environments inside and outside the cell, while the hydrophobic tails face inward creating a semi-permeable barrier. DNA (A) is the genetic material of the cell and is located within the nucleus, not involved in material passage. Proteins (B) and carbohydrates (C) are important components of the cell membrane and play various roles, but they do not directly control the selective passage of materials in and out of the cell.

3. Which of the following colligative properties refers to the elevation of the boiling point of a solution?

• A. Freezing point depression
• B. Vapor pressure lowering
• C. Osmotic pressure
• D. Boiling point elevation

Correct answer: A

Rationale: The correct answer is A: Freezing point depression. Colligative properties are properties that depend on the number of solute particles in a solution, not the type of solute. Freezing point depression is the phenomenon where the freezing point of a solvent is lowered when a solute is added, while boiling point elevation is the opposite effect where the boiling point of a solution is raised. Therefore, the question specifically asked for the colligative property that refers to the elevation of the boiling point, making "Freezing point depression" the correct answer.

4. Which of the following is NOT a greenhouse gas?

• A. Carbon Dioxide
• B. Methane
• C. Oxygen
• D. Water Vapor

Correct answer: C

Rationale: Rationale: A) Carbon Dioxide: Carbon dioxide is a greenhouse gas that is released into the atmosphere through various human activities such as burning fossil fuels and deforestation. B) Methane: Methane is another greenhouse gas that is released from sources like livestock, landfills, and natural gas production. C) Oxygen: Oxygen is not considered a greenhouse gas. It is a vital component of the Earth's atmosphere that is necessary for respiration and combustion. D) Water Vapor: Water vapor is also a greenhouse gas that plays a significant role in the Earth's climate system by trapping heat in the atmosphere. Therefore, the correct answer is C) Oxygen, as it is not a greenhouse gas.

5. A triangular scarf has sides measuring 10cm, 12cm, and 15cm. What is its perimeter?

• A. 27cm
• B. 32cm
• C. 37cm
• D. 45cm

Correct answer: C

Rationale: Simply add the lengths of all sides: perimeter = side1 + side2 + side3 = 10cm + 12cm + 15cm = 37cm.

6. What is the main component that gives bones their rigidity and hardness?

• A. Collagen
• B. Calcium phosphate
• C. Cartilage
• D. Ligaments

Correct answer: B

Rationale: The main component that gives bones their rigidity and hardness is calcium phosphate, which is a mineral compound found in bone tissue. While collagen is a protein that provides flexibility and strength to bones, it is the calcium phosphate that primarily contributes to the hardness and rigidity of bones. Cartilage is a connective tissue that cushions joints and helps with movement, while ligaments are fibrous tissues that connect bones to other bones. Therefore, calcium phosphate is the correct answer as it directly relates to the rigid and hard nature of bones.

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