Term
| Characteristics of an effective pesticide (4 listed) |
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Definition
> Specific
> Biodegradable
> Cost Effective ness
> Not Accumulate |
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Term
| Formula of Net Production |
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Definition
| gross production - respiratory losses |
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Term
| Formula for Energy Transfer |
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Definition
100 multiplied by :
Energy Available after the transfer
-----------------------------
Energy available BEFORE transfer
after/before x 100 |
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Term
| four advantages of using a biological control instead of a pesticide |
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Definition
>Very Specific usually not having a large affect on other species
>Does not leave a chemical in the environment
>cheaper as biological control reproduces itself
> It reproduces itself
>Pests do not become resistant |
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Term
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Definition
| term used to describe a large area in land which only one type of of crop is grown. |
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Term
| 4 techniques intensive farming use which increase the rate of energy conversion |
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Definition
>Restricts movement
>Environmental temperature controlled
>food is controlled (concentrated/specific composition)
>Predators excluded |
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Term
| Explain how restricting movement and controlling environmental temperature increases net productivity ? |
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Definition
Restricted movement reduces respiratory losses.
Controlling the temperature reduces heat loss. |
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Term
| Why do some farmers slaughter animals before maturity? |
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Definition
| more energy is transfered to biomass/tissue production |
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Term
| Describe how AND explain why is 'diet' important in Intensive Farming |
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Definition
| The diet is controlled, thus it is more concentrated. This allows for a higher proportion of digested food to be absorbed. |
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Term
| How do farmers select animals to breed? |
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Definition
| Selected for high productivity (genetically) and bred. |
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Term
| Why is heat loss great in mammals and birds? |
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Definition
| They need to maintain their high body temperature which uses energy. Heat is constantly being lost to the environment! |
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Term
| Why do food chains rarely have more than 5 trophic levels and why does the biomass decrease at higher trophic levels? |
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Definition
| Relative inefficiency of Energy Transfer |
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Term
| Three reasons there is a relative inefficiency of energy transfer: |
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Definition
> Not all organism is eaten
> Not all parts eaten are digested (faeces)
Energy lost in excretory materials (urine)
> Heat loss via respiration and from body to environment |
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Term
| How is efficiency of energy transfer different at the photosynthesis stage and the energy transfer from prey to carnivore? |
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Definition
Efficiency of photosynthesis in plants is low (2%).
Efficency is higher from prey to carnivore as carnivores use more of their food than herbivores. |
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Term
| two disadvantages of using a biological control |
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Definition
>They can become a pest themselves
>There a lag phase (takes time to reduce pest population) |
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Term
| Suggest a way farmers could select cattle to reduce agriduclture's affect on Global warming? (2m) |
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Definition
| Select cows which produce LESS methane which is linked to GREENCHOUE EFFECT |
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Term
| Why would a mammals's mean energy expenditure be higher in winter months? |
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Definition
| It would need to use energy to maintain higher body temperature |
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Term
| Which group of organisms use energy contained in dead matter? |
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Definition
| Decomposers/saprobiotic organisms |
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Term
| Describe how decomposers contribute to recycling of dead matter allowing for plants to use it. (3m) |
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Definition
| They break down complex materials into it's monomers. This releases valuable minerals which are then absorbed by the plant |
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Term
| Equation for photosynthesis |
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Definition
| 6carbon dioside + 6water + ENERGY --> glucose + 6oxygen |
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Term
| The sun's energy is not efficiently converted to a useful form via photosynthethis because.... (4m) |
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Definition
1. 90% reflected back into space
2. Not all wavelengths absorable
3. May not fall on chlrophyll molecule
4. Other limiting factors involves |
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Term
| What unit is used to describe energy available at each trophic level? |
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Definition
> KJ M(-2) YEar (-1)
* (-n) = to the power of |
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