Unit 4: Energy and Ecosystem Flashcards
Why are cattle kept indoors?
LESS energy used in MAINTAINING BODY TEMPERATURE
Why is the biomass of the primary consumers LESS than the biomass of producers in most communities?
- Loss of energy
- by respiration/movement
- LESS ENERGY LEFT TO SUSTAIN HIGHER LEVEL
Advantages of using ORGANIC fertilizers?
- LESS leaching/eutrophication
- LEARN - improves SOIL aeration
- already available
Advantages of using INORGANIC fertilizers?
- known nutrient content
- nutrients are FAST ACTING
- easy to USE/HANDLE
How might large-scale deforestation for agriculture lead to a decrease in the diversity of organisms in the area?
- Removal of forest REMOVES many ECOLOGICAL NICHES
- Reduces NO. OF SPECIES that can exist in the area
How might large-scale deforestation INCREASE the concentration of carbon dioxide?
- Reduce amount of CO 2 for photosynthesis
- Increase amount of CO 2 during combustion
How might large-scale deforestation DECREASE the concentration of carbon dioxide?
LESS RESPIRATION
by PLANTS
Why’s there a difference between amount of solar energy reaching plants and the energy in the biomass of the plants?
- wrong WAVELENGTH
- light REFLECTED
- light MISSES CHLOROPHYLL
DISADVANTAGES of using INORGANIC fertilizers?
- expensive
- could lead to leaching/eutrophication
- doesn’t add to soil structure
Talk about bio-accumulation
___ eats a LARGE NUMBER OF ___
- insecticide REMAINS IN tissues in BODY
- NOT EXCRETED - learn!!!
- insecticide concentration increases up the food chains
- killing top carnivores
Advantages of processing waste in ANAEROBIC digesters rather than in open ponds?
- gases not released
- products can be collected
Anaerobic digesters have cooling systems that are vital. Why are they vital?
- Respiration INCREASES TEMPERATURE!!
- ENZYMES DENATURED
Describe Eutrophication:
- Algae bloom (Orlando Bloom…) dense layer of algae cos nitrates no longer limiting factor for growth
- Light blocked out for plants underneath
- Plants lower down can’t photosynthesise so DIE
- Sapriobiotic bacteria break down and FEED off these dead plants
- So this bacteria grow exponentially
- Bacteria RESPIRE - uses up oxygen
- Fish and other aerobically respiring organisms die cos insufficient oxygen
Give the advantages and disadvantages of using BIOLOGICAL CONTROL: (6 marks)
- Only needs one APPLICATION - reproduces
- KEEPS population LOW
- Pests don’t develop RESISTANCE
- Does NOt leave CHEMICAL RESIDUES in environment; not just environmentally friendly!!!
- Doesn’t GET RID of pest COMPLETLY
- May become a PEST ITSELF
- SLOW acting due to interval time
How does intensive rearing of domestic livestock increases net productivity?
- Fed controlled diet so higher proportion of digested food absorbed
- Movement restricted - less RESPIRATORY LOSS
- Kept inside so LESS HEAT LOSS and predators
- SLAUGHTERED BEFORE MATURITY so more ENERGY is TRANSFERRED to BIOMASS! :(
- Genetically selected for high productivity
