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What is the net movement of molecules and ions from a region of their higher concentration to the lower concentration, as a result of their random movement?
What is the net movement of molecules and ions from a region of their higher concentration to the lower concentration, as a result of their random movement?
What is the main energy source for diffusion?
What is the main energy source for diffusion?
Kinetic energy
Diffusion can only occur in liquids.
Diffusion can only occur in liquids.
False
Which of the following is NOT an example of where diffusion occurs in living organisms?
Which of the following is NOT an example of where diffusion occurs in living organisms?
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What does the rate of diffusion depend on?
What does the rate of diffusion depend on?
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Match the following factors affecting the rate of diffusion with their respective descriptions:
Match the following factors affecting the rate of diffusion with their respective descriptions:
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What is the net movement of water molecules from a region of higher water potential (dilute solution) to a region of lower water potential (concentrated solution) through a partially permeable membrane called?
What is the net movement of water molecules from a region of higher water potential (dilute solution) to a region of lower water potential (concentrated solution) through a partially permeable membrane called?
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What kind of membrane allows water to move through, but not larger molecules like sugar?
What kind of membrane allows water to move through, but not larger molecules like sugar?
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A dilute solution (where there is a lot of water) has a low water potential.
A dilute solution (where there is a lot of water) has a low water potential.
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What happens to an animal cell placed in pure water or a dilute solution?
What happens to an animal cell placed in pure water or a dilute solution?
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What happens to an animal cell placed in a concentrated solution?
What happens to an animal cell placed in a concentrated solution?
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What is the name of a solution that has the same water potential as the cytoplasm of blood cells?
What is the name of a solution that has the same water potential as the cytoplasm of blood cells?
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What happens to a plant cell placed in pure water or a dilute solution?
What happens to a plant cell placed in pure water or a dilute solution?
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What happens to a plant cell placed in a concentrated solution?
What happens to a plant cell placed in a concentrated solution?
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Active transport requires energy from respiration.
Active transport requires energy from respiration.
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What is the process by which plant cells absorb minerals from the soil?
What is the process by which plant cells absorb minerals from the soil?
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Which of the following is NOT an example of active transport in humans?
Which of the following is NOT an example of active transport in humans?
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Study Notes
Chapter 3: Movement into and out of Cells
- Diffusion: The net movement of molecules or ions from an area of high concentration to an area of low concentration, driven by random movement and kinetic energy.
- Diffusion is important for gas exchange in organisms (e.g., CO2 and O2).
- Factors affecting the rate of diffusion:
- Temperature: Higher temperatures increase kinetic energy, increasing the rate.
- Concentration gradient: A larger difference in concentration speeds up diffusion.
- Surface area: A larger surface area increases the rate.
- Distance: Shorter distances lead to faster diffusion.
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Osmosis: A special type of diffusion, involving the movement of water molecules across a partially permeable membrane from a region of high water potential to a region of low water potential.
- Water potential is the measure of the tendency of water to move from one area to another.
- Dilute solutions have higher water potential.
- Concentrated solutions have lower water potential.
- Osmosis in Plants: Cells in pure water absorb water and swell, but cell walls prevent bursting. In concentrated solutions, water leaves the cell, causing it to become flaccid (limp) or plasmolysed (cell membrane pulls away from cell wall).
- Osmosis in Animals: Animal cells in pure water burst. Cells in concentrated solutions shrink. Cells in an equivalent solution maintain their shape.
Active Transport
- Active transport moves substances across cell membranes against their concentration gradient, requiring energy from respiration.
- Active transport is crucial for:
- Absorption of minerals by root hair cells.
- Glucose absorption in the small intestine.
- Glucose reabsorption in the kidneys.
- Specialized protein transporters in cell membranes facilitate this process. These proteins change shape to move substances across the membrane.
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Description
Explore the concepts of diffusion and osmosis in this quiz based on Chapter 3 of your biology curriculum. Understand how temperature, concentration gradient, surface area, and distance influence the movement of molecules and water across cell membranes. Test your knowledge of these essential processes that contribute to gas exchange and cellular function.
