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15 Cards in this Set
- Front
- Back
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What are the features of an animal cell?
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Nucleus, mitochondria, ribosomes, cell membrane, cytoplasm
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What are the features of a plant cell?
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Nucleus, mitochondria, ribosomes, cell membrane, cytoplasm, cell wall, chloroplasts, permanent vacuole
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How are chemical reactions in cells controlled?
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By enzymes, which control the rate of a specific reaction.
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What are enzymes made of?
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proteins
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Where would you find enzymes for:
respiration photosynthesis protein synthesis? |
mitochondria,
chloroplasts ribosomes (surface) |
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What are specialised cells?
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Cells that have adapted to perform a specific function.
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Examples of specialised cells?
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fat cells, cone cells (human eye), root hair cells, gametes (sperm and egg cells)
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How has a fat cell adapted?
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very little cytoplasm
few mitochondria can expand |
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How has a cone cell adapted?
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contains visual pigment
many mitochondria - produces lots of energy end of cell has a synapse |
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How has a root hair cell adapted?
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root hairs increase surface area for water to enter the cell
large permanent vacuole positioned close to the xylem tissue |
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What is diffusion?
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The net movement of particles from an area of high concentration to an area of low concentration.
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What affects the rate of diffusion?
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The concentration gradient - the steeper it is the faster diffusion occurs and the smaller it is the slower the rate will be.
The temperature - an increase will cause particles to move more quickly. |
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What is osmosis?
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The net movement of water from an area of high concentration to and area of low concentration through a partially permeable membrane along a concentration gradient.
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How does osmosis help maintain the body cells at the same concentration?
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If the cytoplasm becomes more concentrated (when water is used up in a chemical reaction) then water moves in by osmosis. Likewise if it becomes too dilute (when water is produced) then water moves out by osmosis.
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What happens when water enters a plant cell through osmosis?
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The cytoplasm swells and presses against the cell wall causing the pressure to build up - no more water can enter the cell. This keeps the leaves and stem rigid and firm.
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