Term
| structures of both animal and plant cells |
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Definition
* nucleus to control cell activity
*cytoplasm where chemical reactions take place
*membrane which controls movement of material
*mitochondia where energy is realesed during aerobic respiration
*ribosomes where protein is made |
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Term
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Definition
*rigid cell wall for support
*chloroplasts contain chlorophyll for photosynthesis
* vacuole containing cell sap |
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Term
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Definition
carry out particular jobs this is called differentiation
this happens much earlier in animals
eg cells in plant may be xylem(root hairs)
eg animal cells may develop into a nerve cell |
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Term
| how do substances get in and out of cells |
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Definition
diffusion is random movement of molecules from area of high to area of lower concentration (does not require energy from cells)
eg diffusion of oxygen into blood stream as cells are respiring
eg carbon dioxide diffusing into photosynthesising plant
eg diffusion of simple sugars and amino acids from gut through membrane |
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Term
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Definition
movement of water through semi or permeable membrane.
Water is needed to support cells and
because chemical reactions take place in the solution |
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Term
| how do plants produce food |
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Definition
photosynthesis (only in GREEN plants)
the equation
Carbon dioxide+water(+light energy) =
glucose + oxygen
Carbon dioxide taken by leaves and water in roots
Chlorophyll traps energy needed
Sugar glucose is made and oxygen given off as waste gas and used for respiration |
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Term
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Definition
if things are limited eg light then photosynthesis slowed down
If cold enzymes would not work effectively
if in enclosed space eg greenhouse CO2 is limited |
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Term
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Definition
for repiration(release of energy from food)
plant combines it with other nutrients to produce new material
glucose is stored by some plants as insoluble starch so it has no effect on osmosis |
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Term
| why do plants need minerals |
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Definition
*for healthy growth
*Nitrates from soil for producing amino acids which are used to make protein.
If deficient then stunted growth
*take magnesium which is essential to produce chlorophyll.
if deficient then yellow leaves |
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Term
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Definition
biomass is mass of living material
pyramid represents mass at each stage in food chain and gives more accurate picture
(mass of bush greater than mass of insects feeding on bush) |
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Term
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Definition
energy loss means not all energy taken in results in growth
energy loss in food chain is due to
*heat
*movement
*waste (faeces and urine)
shown in sankey diagrams |
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Term
| energy in food production |
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Definition
the shorter the food chain the less loss in energy
if animal prevented from moving then more energy in meat so artificially made more efficient
keeping animal in warmer temp so less energy used up maintaining temp of animal |
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Term
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Definition
detrius feeders(eg worms) start the decay by eating dead animals or plants
Decay organisms are microorganisms eg bacteria and fungi
decay faster if warm and wet |
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Term
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Definition
recycling of carbon involves both photosynthesis and respiration
photosynthesis removes CO2
repiration of both plants and animals returns CO2 to atmosphere |
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