Educational worksheet explaining osmosis, including definitions, diagrams of water movement across a membrane, and effects on animal and plant cells.
Worksheet on osmosis showing definitions, diagrams, and effects on animal and plant cells.
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Show Answer Key & Explanations
Step-by-step solution for: GCSE Biology: Diffusion, Osmosis and Active Transport Worksheet ...
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Show Answer Key & Explanations
Step-by-step solution for: GCSE Biology: Diffusion, Osmosis and Active Transport Worksheet ...
Here is the complete solution to the osmosis worksheet, filled in with the correct terms and explanations.
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Osmosis is the movement of a substance from an area of _high_ water potential (no/little solute), to an area of _low_ water potential (more solute), across a _partially_ permeable _membrane_.
* Explanation: Water moves down its concentration gradient — from where there is more water (high water potential, low solute) to where there is less water (low water potential, high solute). This movement happens through a selectively permeable barrier called a partially permeable membrane, which allows water to pass but restricts the movement of larger solute molecules.
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1. Label the two sides:
* Left side: `High Water Potential` (Fewer solute molecules = more water molecules).
* Right side: `Low Water Potential` (More solute molecules = fewer water molecules).
2. Draw arrows:
* Draw one or two large arrows pointing from the LEFT side to the RIGHT side across the membrane.
* Explanation: Water molecules will move *net* from the area of high water potential (left) to the area of low water potential (right) to try to equalize the concentrations on both sides.
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*(You would draw these in the boxes)*
* Cell surrounded by a solution of high water potential (Hypotonic Solution):
* Drawing: A cell that is swollen, round, and possibly bursting.
* Term: Lysis (the cell bursts due to excessive water intake).
* Why? Water enters the cell because the external solution has a higher water potential than the inside of the cell.
* Cell surrounded by a solution of low water potential (Hypertonic Solution):
* Drawing: A cell that is shriveled and shrunken.
* Term: Crenation (the cell shrinks as water leaves it).
* Why? Water leaves the cell because the external solution has a lower water potential than the inside of the cell.
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*(You would draw these in the boxes)*
* Cell surrounded by a solution of high water potential (Hypotonic Solution):
* Drawing: A firm, plump cell with the cell membrane pressed tightly against the rigid cell wall.
* Term: Turgid (the cell is swollen and rigid, providing structural support to the plant).
* Why? Water enters the cell, filling the vacuole and pushing the cytoplasm against the cell wall. The cell wall prevents bursting.
* Cell surrounded by a solution of low water potential (Hypertonic Solution):
* Drawing: A cell where the cell membrane has pulled away from the cell wall, leaving gaps. The cell appears flaccid or shriveled.
* Term: Plasmolysed (the cell membrane detaches from the cell wall due to water loss).
* Why? Water leaves the cell, causing the cytoplasm to shrink. The rigid cell wall remains in place while the membrane pulls inward.
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Animal cells do not have a cell _wall_, if they gain too much water by _osmosis_ they will swell and _burst_, known as cell _lysis_. Plant cells on the other hand do have a cell wall and swell to become _turgid_. If animal cells are placed in a solution of _low_ water potential, water will leave the cell causing it to shrivel, known as _crenation_. When plant cells lose water, the cell _membrane_ pulls away from the cell wall and is said to be _plasmolysed_.
* Explanation Summary:
* The cell wall is the key difference. It protects plant cells from bursting (lysis) in hypotonic solutions, allowing them to become turgid for support.
* Animal cells lack this wall, so they rely on osmotic balance to avoid lysis (bursting) or crenation (shriveling).
* Osmosis is the process driving all these water movements.
* Plasmolysis specifically describes the shrinking of the protoplast (cell contents) away from the cell wall in plant cells under hypertonic conditions.
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This completes the worksheet accurately based on biological principles of osmosis.
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Definition of Osmosis
Osmosis is the movement of a substance from an area of _high_ water potential (no/little solute), to an area of _low_ water potential (more solute), across a _partially_ permeable _membrane_.
* Explanation: Water moves down its concentration gradient — from where there is more water (high water potential, low solute) to where there is less water (low water potential, high solute). This movement happens through a selectively permeable barrier called a partially permeable membrane, which allows water to pass but restricts the movement of larger solute molecules.
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Diagram Analysis (Labeling & Arrows)
1. Label the two sides:
* Left side: `High Water Potential` (Fewer solute molecules = more water molecules).
* Right side: `Low Water Potential` (More solute molecules = fewer water molecules).
2. Draw arrows:
* Draw one or two large arrows pointing from the LEFT side to the RIGHT side across the membrane.
* Explanation: Water molecules will move *net* from the area of high water potential (left) to the area of low water potential (right) to try to equalize the concentrations on both sides.
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Effect of Osmosis on Animal Cells
*(You would draw these in the boxes)*
* Cell surrounded by a solution of high water potential (Hypotonic Solution):
* Drawing: A cell that is swollen, round, and possibly bursting.
* Term: Lysis (the cell bursts due to excessive water intake).
* Why? Water enters the cell because the external solution has a higher water potential than the inside of the cell.
* Cell surrounded by a solution of low water potential (Hypertonic Solution):
* Drawing: A cell that is shriveled and shrunken.
* Term: Crenation (the cell shrinks as water leaves it).
* Why? Water leaves the cell because the external solution has a lower water potential than the inside of the cell.
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Effect of Osmosis on Plant Cells
*(You would draw these in the boxes)*
* Cell surrounded by a solution of high water potential (Hypotonic Solution):
* Drawing: A firm, plump cell with the cell membrane pressed tightly against the rigid cell wall.
* Term: Turgid (the cell is swollen and rigid, providing structural support to the plant).
* Why? Water enters the cell, filling the vacuole and pushing the cytoplasm against the cell wall. The cell wall prevents bursting.
* Cell surrounded by a solution of low water potential (Hypertonic Solution):
* Drawing: A cell where the cell membrane has pulled away from the cell wall, leaving gaps. The cell appears flaccid or shriveled.
* Term: Plasmolysed (the cell membrane detaches from the cell wall due to water loss).
* Why? Water leaves the cell, causing the cytoplasm to shrink. The rigid cell wall remains in place while the membrane pulls inward.
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Key Points (Fill in the blanks)
Animal cells do not have a cell _wall_, if they gain too much water by _osmosis_ they will swell and _burst_, known as cell _lysis_. Plant cells on the other hand do have a cell wall and swell to become _turgid_. If animal cells are placed in a solution of _low_ water potential, water will leave the cell causing it to shrivel, known as _crenation_. When plant cells lose water, the cell _membrane_ pulls away from the cell wall and is said to be _plasmolysed_.
* Explanation Summary:
* The cell wall is the key difference. It protects plant cells from bursting (lysis) in hypotonic solutions, allowing them to become turgid for support.
* Animal cells lack this wall, so they rely on osmotic balance to avoid lysis (bursting) or crenation (shriveling).
* Osmosis is the process driving all these water movements.
* Plasmolysis specifically describes the shrinking of the protoplast (cell contents) away from the cell wall in plant cells under hypertonic conditions.
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This completes the worksheet accurately based on biological principles of osmosis.
Parent Tip: Review the logic above to help your child master the concept of diffusion and osmosis worksheet.
