B4.1 Flashcards
What are the organisms in an ecosystem called
Community
Population
The total number of organisms of each species
Types of organism
Producers
Consumers
Decomposers
Producers
Make their own food by photosynthesis
- plants/ algae
Consumers
Can’t make their own food
Decomposers
Type of consumer. Gain energy by feeding on dead/ decaying material
How is energy transferred between organisms
- energy from transferred by light to chlorophyll in producers
- produces glucose stored energy in bonds
- glucose converted to fats/ proteins/ carbs
- consumer eats producer - when respires the energy stored in the bonds is transferred to atp
What’s at the start of all food chains
A producer
What are the tropic levels
1 - producer
2 - primary consumer - herbivore/ omnivore
3- second consumer - carnivore/ omnivore
What are abiotic factors
Non - living factors
- rainfall/ temperature
What are biotic factors
Living factors
-beech trees/ animals
How does light intensity effect communities
- required for photosynthesis
- evolved to grow - large SA
How does temperature effect communities
- effect in enzymes that control metabolic reactions
- plants develop faster in warmer conditions - higher metabolism
- cold - blooded (lizards) require sun to warm them
How do moisture levels effect communities
- lack of water - death
- plants - flaccid - Wilt
- overwatering - no oxygen/ no respiration - death
How does soil communities effect pH
- some plants grow at different pH levels
- acidic -ferns
- alkaline - cucumbers
What do plants need to survive
- light, water, carbon dioxide, minerals and space
What do animals need to survive
- food water breeding partners space and shelter
Interdependence
Refers to how all organism rely on each other to survive
What is predation
- between predator and prey
What is mutualism
- both organism benefit from the relationship
What is paratism
- only one organism gains (the parasite)
- host suffers
How to calculate biomass
Average mass of each organism x number of organisms present
Why do they take the dry mass of an organism
- water content varies
How much chemical energy do consumers at each trophic level convert
10%
How is biomass lost
- not all eaten - eg. Bones
- used in respiration
- indigestible parts - egestion (removed from body as faeces)
- extraction
How to calculate the efficiency of biomass transfer
Energy after/ energy before
What is nutrient cycling
How materials are passed between biotic and abiotic factors
What are the three types of bacteria in the nitrogen cycle
- nitrifying bacteria (nitrites - nitrates)
- denitrifying bacteria (nitrates - nitrites)
- nitrogen - foxing bacteria (root nodules)
Basic nitrogen cycle
- Nitrogen from air transfers into plants into plants by nitrogen - fixing bacteria/lightning
- plants either eaten by animals ( excretes ammonia) or decomposes (ammonia)
- nitrifying bacteria turns ammonia into nitrites and then nitrates
- denitrifying break down nitrates and release into the air
Water cycle
-precipitation
- percolation - through gaps in soil
- surface run off
(End up in ocean)
- ocean evaporates into water vapour
- transpiration - water vapour
- water vapour condenses
Basic carbon cycle
- plants photosynthesise - take in co2
- plants decompose or animals eat and then decompose
- carbon in decaying waste
(Become fossil fuels or respire away) - fossil fuels burnt - releases co2
(Plants and animals respire - release co2 into atmosphere)
How is carbon dioxide removed from atmosphere
- photosynthesis
How is carbon released into the atmosphere
- respiration
- decomposition - release co2 as they respire
- burning fossil fuels
How do carbon levels vary throughout the day
- photosynthesis only takes place in light/ daytime - less co2 in the day
- respiration carried out all day - more co2 at night cause there’s nothing to absorb it
Decomposers
Break down animal waste
Detrivores
Shredd organic material into very small pieces - larger SA
- digest internally and absorb nutrients
- speeds up decomposition
How do decomposers release nutrients
- secrete enzymes to break down DOM and absorb soluble nutrients back into their body
What factors effect the rate of decomposition
- warm temperatures - denaturing of enzymes - death
- cold temp - slow rate of decomposition
- moist environments - lack of water slows down reactions in microorganisms
- aerobic conditions - oxygen is needed for microorganisms to respire
How to calculate rate of decay
Change in mass/ time
