B4d: Diffusion and osmosis

The materials used in, and produced by, life processes, move through living organisms in several ways, one of the most important of these being diffusion. One such material is water which is needed for key life processes such as photosynthesis, support and transport of materials. Water enters plants by a type of diffusion called osmosis. 

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How do substances move in and out of cells?
By diffusion through the cell membrane.
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What is diffusion?
The movement of a substance from a region of high concentration to low concentration.
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How does water move in and out of cells?
By osmosis through the cell membrane.
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What does the plant cell wall do?
Provide support.
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What can lack of water do to a plant?
Cause it to droop/wilt.
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How does carbon dioxide diffuse in and out of plants through the leaves?
The concentration of carbon dioxide outside the cell is greater than the concentration inside, so carbon dioxide diffuses into the cell.
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How does oxygen diffuse in and out of plants through the leaves?
The concentration of oxygen inside the cell is greater than the concentration inside, so oxygen diffuses out of the cell.
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Why does diffusion only happen in liquids and solids?
There is the random movement of individual particles.
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What three factors increase the rate of diffusion?
A shorter distance, greater concentration gradient and a greater surface area.
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What is osmosis?
Osmosis is the movement of water across a partially-permeable membrane from an area of high water concentration to an area of low water concentration.
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What is osmosis a type of?
Diffusion.
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What does partially-permeable mean?
Allowing some particles to pass through but not others.
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Why does osmosis only happen in water?
There is the random movement of individual particles.
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How are plants supported by turgor pressure within cells?
Water pressure acts against the inelastic cell wall
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What is wilting in plant cells?
A lack of turgor pressure.
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Describe the term flaccid.
A plant cell that is limp.
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Describe the term turgid.
A plant cell fully inflated with water.
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What is the term for a plant cell that has lost water, causing the cell membrane to pull away from the inside of the cell wall?
Plasmolysed.
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How are leaves adapted to increase the rate of diffusion of carbon dioxide and oxygen?
Leaves are thin to reduce the distance that gases have to diffuse through. They are broad with a spongy layer inside to provide a large surface area.
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Describe the effects of the uptake of water on animal cells.
It will eventually burst.
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Describe the effects of the loss of water on animal cells.
It will shrink and become crinkly.
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Why do animal cells shrink, crinkle and burst?
They are not surrounded by an inelastic cell wall.
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What is the term for bursting an animal cell by osmosis?
Lysis.
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What is the term for shrinking an animal cell by osmosis?
Crenation.
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Other cards in this set

Card 2

Front

What is diffusion?

Back

The movement of a substance from a region of high concentration to low concentration.

Card 3

Front

How does water move in and out of cells?

Back

Preview of the front of card 3

Card 4

Front

What does the plant cell wall do?

Back

Preview of the front of card 4

Card 5

Front

What can lack of water do to a plant?

Back

Preview of the front of card 5
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Comments

Alice262

number 7 doesn't make sense 

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