chapter 19 Flashcards
State the principal source of energy to biological systems
the SUN
Describe a food chain
showing the transfer of energy from one organism to the next, beginning
with a producer.
Describe a food web
a network of interconnected food chains and interpret food web
Describe a producer
organism that makes its own organic nutrients, usually using energy
from sunlight, through photosynthesis
Describe a consumer
an organism that gets its energy by feeding on other organisms
How are consumers classed
primary, secondary, tertiary, quaternary
Describe a herbivore
animal that gets its energy by eating plants
Describe a carnivore
an animal that gets its energy by eating other animals
Describe a decomposer
an organism that gets its energy from dead or waste organic material
Pyramid of numbers
Shows the number of organism we are talking about at each level of food chain
Width of the box indicates the number of organisms at that trophic level
Doesn’t always have to be a pyramid shape, as size of organisms is also important
e.g 1 large oak can support many smaller organisms
Rules :
cannot change trophic level
larger an individual , the less of them
Describe pyramid of biomass
Shows how much dry mass the creatures at each level have without all the water that is in the organisms
always a pyramid because mass of organism has to decrease as you go up the food chain
Describe pyramid of energy transfer
shows the amount of energy at each trophic level
always pyramid shape as energy decreases up trophic level
Explain why the transfer of energy from one trophic level to another is not efficient and why usually it is fewer than 5 levels.
Foe energy to be passed on, it has to be consumed
some of the energy is lost through:
1. excretion like urine
2. respiration
3. Heat
4. Undigested waste like faeces
5. some food not digested or eaten
This inefficient loss of energy explains why food chain is usually less than 5 levels
Only 10% of energy is transferred 90% is lost
describe the carbon cycle processes
- Carbon dioxide used for photosynthesis
- Respiration gives out CO2 ( occurs in plants, animals, decomposers )
- Dead plant and animal materials turns into fossil fuel
4.When fossil fuels are burned, carbon combines with oxygen, and CO2 is released . ( COMBUSTION )
- increase use of fossil fuels, increase CO@ in atmosphere. Mass deforestation is reducing producers available to absorb CO2 by photosynthesis, hence increase greenhouse effect
Explain the nitrogen cycle and why nitrogen is needed
Nitrogen needed to make protein why plants need for growth, repair, make enzyme and photosynthesis
Plants nor animals can absorb nitrogen as
1 it is very stbale
2. the bonds need massive amounts of energy to break
a) Nitrogen fixation
Converts nitrogen gas into ammonium by nitrogen fixing bacteria in root nodules.
Lightning can also ‘fix’ nitrogen gas by slitting bonds and turning them into nitrogen oxide which dissolve in rain and leech into soil
b) Nitrification
Plants cannot absorb ammonium, so ammonium converted to nitrites then nitrates by nitrifying bacteria
c) Absorption
Nitrate absorbed into plants by active transport.
d) Decomposition and deamination
Animals eat plant , waste from animals decompose. The amino acid undergoes deamination to form ammonia and ammonium compound
e) Denitrification
denitrifying bacteria found in poorly aerated soil
This bacteria takes nitrates out of soil and converts them back into nitrogen gas
