UNIT 5 - 'On the wild side' (ecosystems, photosynthesis and climate change) Flashcards
excepto p102-105 y 113
What is meant by ecosystem?
The biotic factors, like living organisms, and abiotic factors, such as climate, in an area.
What is meant by habitat?
The place where an organism lives.
What is meant by population?
All the organisms of one species in one area.
What is meant by community?
All the organisms of different species that live and interact in the same habitat.
What is meant by biotic factors?
The living features of an ecosystem (i.e. predators or food)
What is meant by abiotic factors?
The non-living features of an ecosystem (i.e. temperature or availability of water).
What is interspecific competition and how does it arise?
The competition between different species. i.e. two species share the same source of food and so when there’s a shortage, both species compete for the food and the populations can’t grow much.
How does this graph sow intraspecific population?
- When there’s plenty of resources, the population increases, and so does competition.
- Eventually resources become limiting because of the increasing competition and so the population begins to decline.
- In the smaller population, there’s less competition for resources and so the population starts to grow again.
- The maximum stable population size of a species that an ecosystem can support is the carrying capacity.
What is the carrying capacity?
The maximum stable size of a species that an ecosystem can support.
The lynx is the predator and the snowshoe hare is the prey.
What happens at each of the stages in the graph?
- As the prey population increases, there’s more food available and so the predator population grows.
- As the predator population increases, more prey is eaten and so the prey population starts to fall.
- As prey population falls, there’s less food for the predators and so the predator population also falls.
How does distribution of a species vary due to abiotic and biotic factors?
Abiotic: Orientation (for higher solar input), minerals in soil, temperature in some regions is too low/high.
Biotic: Species may be out-competed in some areas where other species are dominant so they will grow in other areas.
What is a niche?
Role of a species within its habitat, including biotic interactions (such as the organism it eats) and abiotic interactions (such as the oxygen consumed and carbon dioxide excreted). Every species has its own niche.
Can two species occupy the same niche? Why?
No. every species has its own niche.
Otherwise, the species would compete (i.e. for the same food source) and therefore the populations would decrease.
What is succession?
The process by which an ecosystem changes.
When does primary succesion happen?
When land has been newly exposed or fromed, so there’s no soil to start with.
(i.e. Volcano has erupted exposing new land, sea level has dropped, exposing new land)
When does secondary succession happen?
When a land has been cleared of all plants but the soil remains.
(i.e. after a forest fire)
How does primary succession come about?
- Seeds and spores are blown by the wind and they begin to grow in harsh abiotic conditions. These pioneer species are the first to colonise the area.
- Pioneer species start to change the abiotic conditions - they die and microorganisms decompose the organic material (humus) into soil, or decompose rocks.
- The abiotic conditions are less harsh (i.e. more soil to retain water) and bigger, better adapted to the new conditions species grow there, adding to the richness of soil and minerals when they die. They also outcompete some of the first species that aren’t adapted to the new conditions.
- Biodiversity keeps increasing until the climax community is reached - the largest, most complex community of plants and animals the ecosystem can support.
What is the climatic climax?
The climax ccommunity for a specific climate.
What is the climax community called when succession is stopped artificially?
Plagioclimax
What is phosphorylation?
Adding phosphate to a molecule.
What is photophosphorylation?
Adding phosphate to a molecule using light.
What is photolysis?
The splitting of a molecule using light.
What is hydrolysis?
The splitting of a molecule using water.
What is the chemical equation for photosynthesis?
6CO2 + 6H2O > C6H12O6 + 6O2