POPULATIONS AND ENVIRONMENTS Flashcards
Population
a group of interbreeding organisms of one species in a habitat
Community
all the populations of different organisms living and interacting in a particular place at the same time; group of different species form a community
Ecosystem
Made up of all the interacting Biotic and Abiotic factors
Ecological Niche
the role of a species in an ecosystem; it is governed by the adaptation of the animal to biotic and abiotic factors.
When does inter-specific competition occur
INTERSPECIFIC COMPETITION TAKES PLACE WHEN TWO SPECIES HAVE OVERLAPPING NICHES (this is because no two species can coexist in the same habitat if they have the same niche). Therefore if two species are observed to compete then they must have the same niche.
Therefore two species which have different niches will provide a maximum yield as each will exploit the environment more effectively.
Species
a group of interbreeding individuals which produce fertile offspring
Why ecosystems rarely have more than five trophic levels
Not enough energy left as there are energy loses between trophic levels
How Producer converts energy to biomass
Uses energy for photosynthesis
Materials are synthesised to be used for growth
The chemical energy is stored
Why dry biomass of animals to dry biomass of plants is always a lot less than one
Plants are producers and animals are consumers
Energy is lost between trophic levels due to loss of energy through respiration, heat, etc.
How Decomposers may work on dead matter to make the contents available to a plant
Secrete enzymes for digestion of dead matter, usually it is starch
Digestion produces sugars and nitrogenous waste
The nitrate (nitrogenous waste) is taken up by plants
Decomposers absorb the sugars (glucose) produced from digestion and use them for aerobic respiration
As decomposers respire they produce Carbon Dioxide may be used by the plant leaves in photosynthesis
However they also use up Oxygen as they respire, therefore reducing diversity of oxygen dependant organisms
Decomposers will also change subject to temperature and pH
Difference between decomposers and detritivores
Decomposers secret enzymes for extracellular breakdown of organic matter
Detritivores ingest organic matter
Limitations of Pyramid of Numbers
1) No accounts is taken of size
2) Numbers of certain organisms can be so great that they cannot be represented using the same scale as other species
Ways in which larger plants affect smaller plants
when a plant is larger than another plant, it not only takes away the outcompeted plant’s sunlight, but also provides it with shade, therefore keeping the temperature constant Reduce light Reduce water Reduce mineral ions Reduce wind Increase humidity Reduce temperature
Measurement used in order to find rate of photosynthesis
Oxygen produce PER UNIT OF TIME
