Nursing Elites

1. Passive transport does not require energy input from the cell. Which of the following is an example of passive transport?

• A. Active transport of ions across a membrane
• B. Diffusion of small molecules across a concentration gradient
• C. Movement of large molecules using vesicles
• D. Endocytosis of particles into the cell

Correct answer: B

Rationale: Passive transport refers to the movement of molecules across a cell membrane without the input of energy. Diffusion of small molecules across a concentration gradient is a classic example of passive transport, as it occurs spontaneously from an area of high concentration to an area of low concentration. Active transport (option A) requires energy input in the form of ATP to move substances against their concentration gradient. Movement of large molecules using vesicles (option C) involves processes like endocytosis and exocytosis that require energy in the form of ATP. Endocytosis of particles into the cell (option D) is an active process that requires energy expenditure by the cell to engulf and internalize extracellular substances.

2. Which of these organs is NOT involved in the production of digestive enzymes?

• A. Mouth
• B. Stomach
• C. Pancreas
• D. Small intestine

Correct answer: A

Rationale: A) Mouth: The mouth is involved in the mechanical breakdown of food through chewing and the initiation of carbohydrate digestion by the enzyme amylase in saliva, but it does not produce digestive enzymes. The salivary amylase in the mouth helps in breaking down carbohydrates. However, it is not an organ that produces digestive enzymes. B) Stomach: The stomach produces gastric juices containing enzymes like pepsin that help break down proteins. C) Pancreas: The pancreas produces various digestive enzymes such as amylase, lipase, and proteases that aid in the digestion of carbohydrates, fats, and proteins. D) Small intestine: The small intestine produces enzymes such as peptidases, sucrase, lactase, and maltase that further break down proteins, carbohydrates, and fats for absorption. Therefore, the mouth is the organ that is NOT involved in the production of digestive enzymes.

3. What is the main function of the respiratory system?

• A. To absorb nutrients
• B. To exchange gases
• C. To transport oxygen
• D. To regulate blood pressure

Correct answer: B

Rationale: The main function of the respiratory system is to exchange gases, primarily oxygen and carbon dioxide, between the body and the environment. Option A, 'To absorb nutrients,' is incorrect because the respiratory system is not involved in nutrient absorption. Option C, 'To transport oxygen,' is partially correct, but it doesn't encompass the complete role of gas exchange that includes both oxygen and carbon dioxide. Option D, 'To regulate blood pressure,' is incorrect as blood pressure regulation is primarily controlled by the cardiovascular system, not the respiratory system.

4. Which of the following statements is true regarding a supersaturated solution?

• A. It is unstable and tends to crystallize
• B. It contains more solute than it could dissolve
• C. It has a higher concentration than a saturated solution
• D. It is rarely encountered in everyday solutions

Correct answer: A

Rationale: A supersaturated solution is unstable and tends to crystallize because it contains more solute than it could dissolve at a given temperature. This excess solute is in a metastable state and can precipitate out if disturbed, leading to the formation of crystals. Option B is incorrect because a supersaturated solution does contain more solute than it could normally dissolve, but it becomes unstable due to this excess solute. Option C is incorrect because while a supersaturated solution does have a higher concentration than a saturated solution, the defining characteristic related to its instability is the excess solute. Option D is incorrect as supersaturated solutions can be encountered in various everyday scenarios, such as certain sugar solutions used in cooking or rock candy production.

5. What is the primary function of lymph nodes, small, bean-shaped structures found along lymphatic vessels?

• A. To store excess lymph fluid
• B. To produce red blood cells
• C. To filter lymph and fight infection
• D. To transport lymph to the heart

Correct answer: C

Rationale: Lymph nodes primarily function to filter lymph and fight infection. They contain immune cells that help to remove pathogens and foreign particles from the lymph fluid as it passes through the nodes. This process helps to activate the immune response and defend the body against infections. Choice A is incorrect as lymph nodes do not store excess lymph fluid; they filter lymph. Choice B is incorrect as the production of red blood cells primarily occurs in the bone marrow, not in lymph nodes. Choice D is incorrect as lymph nodes do not transport lymph to the heart; they filter and process lymph to remove impurities and activate the immune response.

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