Pretend you are a teacher preparing a quiz for the text I will provide. 
            Each quiz question should follow the format below. 
            Ensure that you carefully recheck the questions and answers for accuracy. 
            The output should be a ready-to-use list of dictionaries for the Python eval function:

            [

                    "question": "WRITE THE QUESTION HERE",
                    "options": ["A) OPTION_1", "B) OPTION_2", "C) OPTION_3", "D) OPTION_4"],
                    "answer": INDEX_OF_CORRECT_ANSWER_IN_OPTIONS_LIST,
                    "explanation": "EXPLAIN WHY THE ANSWER IS CORRECT"

            ]

            Text:
            dy Fluids 
Body fluids contain water and solids. 
Solids are organic and inorganic substances. 
•
Organic Substances 
Organic substances are glucose, amino acids and other proteins, fatty acids and other lipids, 
hormones and enzymes. 
•
Inorganic Substances 
Inorganic substances present in body fluids are sodium, potassium, calcium, magnesium, 
chloride, bicarbonate, phosphate and sulfate. 
ECF contains large quantity of sodium, chloride, bicarbonate, glucose, fatty acids and oxygen. 
ICF contains large quantities of potassium, magnesium, phosphates, sulfates and proteins. 
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Composition of the ECF and ICF
1.
ECF (Extracellular fluid):  
The main cation (+) is Na+, Ca2+ and Mg2+ .
The main anion (-) is Cl-, HCO3-, proteins, SO4-.
2.
ICF (Intracellular fluid):  
The main cation (+) is K+ and Mg2+ and small 
amount of Na+.
The main anion (-) is PO4-, proteins and small 
amount of Cl-, HCO3- and SO4-.
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Composition of the ECF and ICF
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Fluid exchange between the ECF and ICF
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TONICITY
• Usually, movement of water between the fluid compartments is not influenced by small
molecules like urea and alcohol, which cross the cell membrane very rapidly. These small 
molecules are called ineffective osmoles. 
• On the contrary, the larger molecules like sodium and glucose, which cross the cell membrane 
slowly, can influence the movement of water. Therefore, such molecules are called effective
osmoles. 
• Osmolality that causes the movement of water from one compartment to another is called 
effective osmolality and the effective osmoles are responsible for this. 
• Tonicity is the measure of effective osmolality, in terms of tonicity, the solutions are classified 
into three categories: Fluid exchange between the ECF and ICF
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i. Isotonic fluid 
ii. Hypertonic fluid 
iii.Hypotonic fluid. 
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
Net movement of water through a semi-permeable membrane.

Movement of water is towards the compartment containing less water.
Osmosis
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For osmosis to occur in practice:
Solute concentrations in the both sides of the membrane must be different.
Membrane must be semi-permeable to solutes.
07.08.2024 Fluid exchange between the ECF and ICF
For osmotically active solute:
Solutes that cannot pass the membrane.
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Osmolality : it is the concentration of osmotically active substance in the solution. Osmolality 
is expressed as the number of particles (osmoles) per kilogram of solution (osmoles/kg H2O).
Osmolarity: . It is the number of particles (osmoles) per liter of solution (osmoles/L).
Osmolality and Osmolarity 
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Osmotic pressure in solutions depends upon osmolality. However, in practice, the osmolarity and 
not osmolality is considered to determine the osmotic pressure because of the following reasons: 
i. Measurement of weig

            Quiz: