ECOLOGY Flashcards
Species
a group of organisms that can interbreed and produce offspring
- have similar physiological and morphological characteristics
- can interbreed to produce fertile offspring
- genetically distinct from other species
- have common phylogeny
Hybrid
when two similar species mate to produce infertile offspring
ecology
study of the relationships between living organisms and their environment
habitat
the environment in which a species normally lives (location of living organism)
population
a group of organisms of the same species who with each other at the same time
community
a group of populations living and interacting with each other at the same time
ecosystem
a community and its abiotic environment
distribution
geographical range of an organism
niche
ecological role and space that an organism fills in its ecosytem
autotroph
an organism that synthesizes its own organic molecules from simpler inorganic substances
- convert light energy into chemical energy
e. g. grass, cyanobacteria, algae
heterotrophs
an organism that obtains organic molecules from other living organisms and their dead remains
e.g. zooplankton, sheep, insects, fish
detritivore
(decomposer/hetereotroph); an organism that obtains organic molecules from detritus by internal digestion
(obtains nutrients by injesting non living matter)
e.g. vultures, earthworms, woodlice
saphotroph
(decomposer/heterotroph); obtain organic nutrients from dead organism by external digestion (secretes enzymes and abosrbs broken down molecules)
e.g. fungi and bacteria
what do decomposers aid in
nutrient recycling
polulation isolation
- populations can be separated from the rest of the species and evolve differently to form a new species
e. g. bodies of water or physical objects can separate species
systematic sampling techniques
- use of a quadrat
-use of transect
(RANDOM SAMPLING) - determine frequency and distribution
Abiotic factors
Abiotic and biotic factors
Abiotic: temperature, light, pH, air humidity, etc
NUTRIENT RECYCLING
Ecosystems recycle carbon, nitrogen and other elements/compounds necessary for life as there aren’t enough mineral needs for all the organisms in the biosphere
Organisms absorb valuable minerals and organic compounds and use them to build their cells
They are gained through feeding and then strorage
Released through excretion, respiration/photosynthesis and decomposition
This recycling makes ecosystems sustainable and productive
examples of nutrient recycling
- nitrogen cycle (nitrogen fixation by bacteria in root nudules; supplied by faeces and urine)
- carbon cycle
DECOMPOSERS:
DECOMPOSERS:
Decay
Decomposers (saprotrophs and detritivores) break down the body part of dead organisms through digestive enzymes that convert the organic matter into usable form
Decomposers recycle nutrients; play a major role in soil formation, which plants need (humus layer of organic debris and nutrients released)
energy origin in food chain
This energy derived from the sunlight, converted to chemical energy by photosynthesis in autogrophs, travels up the food chain in heterotrophs by feeding in an energy flow. As the energy rises up the food chain, loses a tenth of its original energy. HEAT(energy) CANNOT BE RECYCLED
why is biomass restricted in the food chain
Energy is released from carbon compounds by respiration and is used in living organisms and converted to heat
However living organisms cannot convert heat to other forms of energy
The energy losses between trophic levels therefore restrict the length of food chains and biomass of higher trophic levels, meaning that tertiary consumers must consume more than a primary producer to gain energy
90% of sunlight energy goes back into space
Low Carbon Dioxide Levels are a limiting factor photosynthesis
Photosynthesis
light –> chemical energy
6CO2 + 6H2O—> C6H12O6 + 6O2
-energy derived from sunlight and travels up food chain
how is energy lost in the food chain
Energy is lost in a food chain by:
1) Cellular respiration releasing energy as heat
2) Undigested material released as feces since it was not absorbed or assimilated in the body of the organism
3) Death of an organism before it is consumer by an organism in the next trophic level
4) Not all of the organism consumer in the first place as food, abandoned food is left to decayp
CARBON CYCLE + carbon sinks
CARBON CYCLE
Autotrophs convert carbon dioxide into carbohydrates and other compounds, which are then used.
How can we calculate the size of carbon sinks? We can’t because of their fluxes.