Flashcards
AQA A2 Biology - Chapter 5 Energy and Ecosystems
Flashcards do conjunto (20)
- 1What is a producer?Photosynthetic organisms which produce carbohydrates (glucose) from carbon dioxide using energy from the sun
- 2What are consumers? - Distinguish between primary, secondary and tertiary consumersOrganisms which obtain their energy by eating or consuming other organsisms;
Primary consumers directly eat producers;
Secondary consumers eat the primary consumer;
Tertiary consumers eat the secondary consumer - 3What is a decomposer? - Give an exampleOrganisms which break down energy in dead plants and animals releasing the minerals and elements stored within them:
Examples include fungi and bacteria;
Earthworms are detritivores - 4What is the difference between a food chain and a food web?Both describe the feeding relationships between organisms;
Food chain shows one organism eating another
Whilst food webs show the complex relationships between organisms - 5What is the principle source of energy in all ecosystems?The sun
- 6Describe four ways energy is lost between the sun and the producerApproximately 90% of the sun's energy is reflected
Not all wavelengths can be absorbed
Light may not fall on the chlorophyll
Photosynthetic limiting factors - 7Describe four ways energy is lost between the producer and the consumerSome of the organism isn't eaten
Some part of the organism cannot be digested
Energy lost in excretory materials
Heat losses - to the environment or due to metabolic activity (respiration) - 8What is the equation for energy efficiency?Energy transfer = (energy available after the transfer) / (energy available before the transfer)
- 9Give the equation for net productionNet production = gross production - respiratory losses
Gross production is the total quantity of energy that the plants in a community convert to organic matter - 10What are the drawbacks associated with a pyramid of number?No account taken for size
Numbers can be so great it is impossible to represent them accurately - 11What are the advantages and disadvantages associated with a pyramid of biomass?Does take into account the size of an organisms
But organisms must be dead - 12Why is a pyramid of energy often the best choice?More reliable
Most accurate representation of energy flow - 13What are the units associated with energy in an energy pyramid?kJm^-2year^-1
kJ per metre squared per year - 14What is an agricultural ecosystem?Made up of domesticated animals and plants to produce food;
Try to maximise energy from the sun transferred to humans - 15What is productivity, in relation to plants?Productivity is the rate at which something is produced
Gross productivity is the rate at which plants assimilate energy from the sun into chemical energy
Net productivity = gross productivity - respiratory loses - 16Give to additional sources of energy in an agricultural ecosystemFood the farmer eats in order to do work
Fossil fuels used by machinary - 17What four things should a pesticide be?Be specific
Bio-degrade
Be cost effective
Not accumalate - 18Describe biological control of pests:Aims to control pest numbers not eradicate them
Pest control organism may become a pest itself
Pests will not become resistant
Once introduced will reproduce themselves - 19What does integrated pest control involve?Choosing a plant to suit the local area,
Providing a habitat for natural predators,
Regular monitoring,
Removing pest mechanically,
Use of biological agents,
Using pesticides as a last resort - 20How is energy conserved when rearing livestock?Constricting movement,
Keeping environment warm to reduce energy lost through thermoregulation,
Controlling feeding so they receive the optimum amount of food,
Excluding predators,
Selective breeding to produce species that are efficient at converting food to biomass,
Use of hormones to increase growth
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- FlashCards sobre AQA A2 Biology - Chapter 5 Energy and Ecosystems , criado por Charlotte Lloyd em 26-05-2015.
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- Charlotte Lloyd
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