Organisms & environment Flashcards
Define ecosystem
- cycles of energy
- habitat
- food web
- interacting organisms
What do plants need
- water H2O
- Nitrates NO3-
- phosphates Po4-
- Magnesium Mg2+
- potassium K+
- Carbon dioxide Co2
ideally, what would be the best pyramid to show trophic levels
Pyramid of Productivity
(looking at what has been eaten instead of what is eating)
What can disrupt a food web?
What would disruption cause?
- pesticides
- invasive species
- overpopulation
- pollution
- lack of natural resources
- damaged habitat/ ecosystem
- biomagnification
Why is human population increasing so much
industry/tech ≠ predation
agricultural revolution ≠ extreme lack of food
medicine ≠ diseases
Sadly we still have competition, e.g. war and poverty
Define : Population
group of organisms of some species
Define : Community
populations of several species, both plants and animals
Define : Ecosystem
communities + the environment they live in
What is carrying capacity
the amount of organisms a habitat/environment can sustain
What is the biological balance equation that represents changes in population
n. of birth + immigration = n. of death + emigration
This needs to be balanced, otherwise there will be an increase or decline in population
How efficient is energy transfer from organism to organism
Only 10%
🤯
Whaaaaat? Crazyyy!!!
What is light energy converted into
chemical energy
What are the differences, advantages and disadvantages of pyramid of numbers or biomass
NUMBERS :
represents energy transfer and number of organisms on each trophic level
disadvantage: doesn’t show values of energy transfer or biomass
BIOMASS :
represents transfer of biomass on each trophic level.
We can work out percentages of transfer efficiency.
disadvantage: doesn’t show quantity of organisms or energy distribution
What is biomass
Total dry mass of living matter and chemical energy
What is a detrital food chain and a detritivore ?
What is decomposer?
Starts with dead material instead of sunlight
Detritivores eat dead material (like dead leaves)
Decomposer decays bodies of dead organisms
Define :
Trophic level
Decomposer
Food chaine
producer
consumer
Herbivore
carnivore
EMPTY
What level of organism do all organisms rely on?
Producer
What is the name of the process of amino-acids -> urea
Deamination
Respiration / Photosynthesis
What are equations which produces raw biomass?
(plant-based material used as fuel)
Photosynthesis
Oxygen + glucose —> water + carbon dioxide
carbon dioxide + water —> oxygen + glucose
I
Sunlight
Define Biomagnification
Accumulation of chemicals
mostly affects higher on food chain
In population growth, what is the:
1. lag phase
2. exponential phase
3. transitional phase
4. plateau phase
- Species introduced to new habitat. Takes time to adjust.
- plenty of resources, food, space, barely no factor limiting growth. rapide increase.
- no longer enough resources, increase in predators and diseases, growth rate falls, death rises, but still overall slow increase
- carrying capacity reached. Constant population self balancing (see population notes)
Why is carbon always moving places in nature
it is constantly going through organisms as glucose, in the atmosphere as CO2 and is generally always part of a cycle.
What is the carbon cycle
The cycle in which carbon is absorbed and assimilated by organisms ans released back into the atmosphere
What are the processes in the carbon cycle
–> Carbon dioxide in air
–> Photosynthesis
–> Respiration in plants (back to air)/feeding & assimilation
–> Respiration in animals/death/egestion
–> decomposition (and then decomposers respire and carbon goes back into air)/fossilisation
–> combustion (carbon released back into air)
Describe the nitrogen cycle
- Nitrogen gas in air
- Can be fixed into nitrates by lighting, root nodule bacteria and some fertilisers
- Plants absorb nitrates and assimilate it
- Animals ingest plants, digest plant proteins to amino acids then assimilate them to make their own proteins
- Either animals die, or perform egestion or excretion, and proteins are broken down to amino acids which are transferred to urea in the body
- Urea is decomposed to ammonia by decomposers e.g. decomposing bacteria
- Ammonia is nitrified by nitrifying bacteria into nitrites then nitrates
- The nitrates are either denitrified by denitrifying bacteria or absorbed by plants again
What are the 4 bacteria in the nitrogen cycle
nitrification (oxidation) bacteria - ammonia —> nitrate
denitrification bacteria - nitrate —> nitrogen
nitrogenific root nodule bacteria - nitrogen —> nitrate
decomposing bacteria - urea —> ammonia
What are the benefits of root nodule bacteria?
(for both in symbiosis)
Plants get nitrate
bacteria gets glucose and protection
What type of process happens in root nodules
mutualistic/ symbiotic process:
Nitrogen fixing
nitrogen —> nitrates
What happens between dead organic material and absorption of nitrate by plants
(nitrogen cycle)
Dead matter → protein → amino-acids →ammonia → nitrates → absorbed by plants
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Decomposition by decomposers like worms or nitrified by nitrification bacteria
decomposing bacteria
