Environment:
Ecology and its terms:
Ecology is the study of the ecosystem. An ecosystem is a place where living (biotic) and non-living things (abiotic) exist and interact with each other.
Levels of organization in ecology:
Individual / Organism - individual living being that can act independently ( An adult organisms that can reproduce).
Population - a group of organisms belonging to the same species living in the same area.
- Attributes of the population are birth rate (reproduction per time), the death rate (death per time) and sex ratio (number of females per 1000 male).
- Population calculating terms: Natality (number of births), Mortality (number of deaths), Immigration, Emigration.
Interactions between populations:
Positive Interactions - Interactions between two species where none of the species gets harmed.
Types:
Mutualism (+,+):
- Both species get benefitted.
- Example: Mutualism between zebra and oxpeckers. Oxpeckers eat the parasites present in the zebra's body, so oxpeckers get food & zebra gets the parasites removed from its body
- Both can survive without the other.
Symbiosis (+,+):
- Both species get benefitted but neither can survive without the other.
- Example: Bucket Orchid and Orchid bees. Bucket orchids secrete and drip a fluid in their "bucket". The male orchid bees fall into the "bucket" to cover themselves with the fluid. This attracts the female bees. The bee then uses the fluid in its courtship with a female bee and deposits the pollen on the stigma of the next bucket orchid that it enters.
- Neither can survive without the other. If there are no orchid bees, pollination cannot happen between the Bucket orchids (No insect can crawl and come out of the bucket, except orchid bees). If there are no Bucket Orchids, the Orchid bees cannot attract the female bees then their population would decline.
Commensalism (+,0):
- One species gets benefitted. The other species neither gets harmed nor benefitted.
- Example: Zebra shark and remora fish. By attaching itself to the shark, the remora fish is carried along by the shark, allowing it to travel to different areas without having to expend its energy to swim. The shark is unaffected by the remora's presence.
