VII. Ecology Flashcards
Define tropic level
the position an organism occupies in a food chain
What are Herbivores and give an example of a Herbivore food chain
animals that deriver their energy from plants
Grass/leaves – bunny/cow/Zebra
What are Carnivores and give an example of a Carnivores food chain
animals that deriver their energy from meat
Grass – bunny – wolves
What are Destruents?
an organism that causes the decay of dead organic material to obtain nutrients (decomposer) e.g. bacteria (last stage in the tropic level)
Give an example of a food chain (at least 4 levels)
Grass - grasshopper - frog - snake - hawk
What are the basic elements of ecological niche?
Niche is term describing how a population responds to the distribution of resources and competitors (by growing when resources are abundant) and how it in turn alters those same factors (limiting access to resources by other organisms). Abiotic or physical environment is part of niche because it influences how populations affect, and are affected by resources and enemies. No two species can occupy the same niche in the same environment for a long time. Also biotic environment, that influences population such as predation, diseases.
Organism tolerance for environmental factors changes?
An organism’s ability to tolerate changes can affect both its ability to survive and reproduce in an existing ecosystem and its ability to move to new ecosystems. Some organisms have adapted to survive in environments that the vast majority of other organisms on Earth could not tolerate. There are abiotic factors such as temperature, soil type, and air or water pressure. Also biotic factors, such as competition. diseases, predation and parasitism.
Describe the basic characteristics of populations
All species experience similar ecological processes at a particular stage of the life cycle. All the populations of different species of a particular geographical area collectively constitute a biotic community. In a geographical area, the population is further divisible into sub-groups called demes. The chances of sexual communication are more between the members of same deme than between the members of different demes. Due to this mating ability, there is free flow of genes in a species.
Population of an area is described on the basis of three parameters:
•Number and kind of individuals of a species
•A given space or an area.
•Time.
Competition
Organisms of different species compete for the same resource in an ecosystem. It is only one of many interacting biotic and abiotic factors that affect community structure, and it has the potential to alter populations, communities and the evolution of interacting species.
Predation
Predation may occur as prey interactions and cannibalism. Prey predations ex. Aposematic prey, colouration and sound, can hid, detect and attack.
Parasitism
Organism that obtains its nutrients from one or a very few host individuals, causing harm but not causing host death immediately.
Mutalism
Interaction between two or more species derives a mutual benefit. It is the closeness of association, one or more species involved in the interaction may be obligate, they cannot survive in short or long term without the other species
Comensialism
It benefits one organism and the other organism is neither benefited not harmed. Ex. Remora living with a shark, it eats leftover food from the shark, and the shark is not affected in this process.
Terrestial ecosystem
can be found anywhere apart from heavily saturated places. They are classed into:
Forest = ecosystem abundant of plants, living organisms is quite high; a small change could affect the whole balance.
Desert = ecosystem that receive annual rainfall. Has extremely high temperature, low water, stems and leaves are modified for specific plants and adapted animals.
Grassland = ecosystem located in tropical and temperate regions. Comprises grasses with little number of trees.
Mountain: ecosystem provides diverse array of habitats where large number of animals and plants can be found. Plants are modified to live in the high altitude, animals are adapted.
Water ecosystem
this ecosystem found in body of water, two main types:
Marine = are the biggest ecosystem on the earth, water in marine ecosystem has high amounts of minerals and salts dissolved in them ex ocean
Freshwater = it is the contrary of marine ecosystem, occupy smaller earth’s surface, contain very little water
