Ecology Flashcards
What is a food chain or web?
A food chain is a simple model that scientists use to show how matter and energy move through an ecosystem, from one animal to another. A food web is more complex and shows all possible relationships, so an animal can be eaten by multiple predators. Webs are more accurate.
What are autotrophs and heterotrophs?
Autotrophs make their own energy out of light or chemical compounds. Heterotrophs cannot make their own energy and feed on autotrophs or other heterotrophs who feed on autotrophs. Autotrophs are also known as producers, and heterotrophs are called consumers.
What are decomposers?
Decomposers break down the compounds of dead or decaying animals and plants into molecules that can be absorbed into the earth
What are herbivores, carnivores, omnivores, and scavengers?
Herbivores are organisms which only eat plants, carnivores eat animals, omnivores eat both, and scavengers eat only already dead animals.
Why are decomposers necessary, especially in rainforest ecosystems?
Decomposers complete the energy cycle, which is important in rainforests where there is a lot of debris.
What percent of energy transfers from one trophic level to the next?
10%
How does the amount of energy lost between trophic levels limit ecosystem populations?
The higher up on the food chain, the smaller the population
What are biotic and abiotic factors?
Biotic factors are living parts of an organism’s environment, while abioic factors are the nonliving parts.
What are the two models of population growth?
Exponential growth, shown by a J-shaped curve, and linear growth, shown by a straight line
What is carrying capacity?
The number of organisms that can be supported by an ecosystem, kept in place by limiting factors.
What are primary, secondary, and tertiary consumers?
Primary consumers eat autotrophs, secondary consumers eat primary, and tertiary consumers eat secondary.
What are three methods for checking the number of organisms in a population and their benefits and drawbacks?
Scientists practice catch and release, where they mark organisms, release them, and recapture a sample of the same organisms later. Using the ratio of unmarked and marked organisms, they can estimate the population. There is also sampling, where all the organisms in a specific area are counted, and a complete counting of organisms.
How does competition affect populations?
When animals must compete over resources, it keeps down populations because demand cannot exceed supply.
What resources do organisms compete over?
Abiotic and biotic factors eg food water and territory
What are the zones of aquatic ecosystems and where are they found?
Intertidal, where the ocean meets the land; pelagic, the open ocean; benthic, the area below the pelagic but above the deepest ocean; and abyssal, the deepest parts of the ocean.
