7. Ecology 2 Flashcards
Define population .
A species that occupy the same habitat
Define habitat
The place in which an organism lives
Define community
Populations of different species interacting
Define ecosystem
The interactions between the biotic and abiotic factors in an area
What do food chains show ?
Food chains show the feeding relationships of different organisms and the flow of energy between the organisms
Define biomass
The total mass of living material
What are trophic levels ?
The stages in a food chain
What do arrows in a food chain represent
The direction of biomass transfer
Describe a simple food chain
Producer —> primary consumer —> secondary consumer —> tertiary consumer
What is a producer?
An organism that makes its own food
What types of organisms are primary producers ?
Photosynthetic organisms like green plants and alagae that trap energy from the sun
What is a primary consumer?
An organism that feeds on producers
What is a secondary consumer ?
An organism that feeds on primary comsumers .
What is a tertiary consumer ?
An organism that feeds on secondary consumers
What is a predator ?
A consumer that kills and eats other animals
What is prey ?
An animal that is killed an eaten by another animal
Describe the pattern of predators and prey in a stable community
The numbers of predators and prey rise and fal in cycles
Why are producers the first trophic level ?
- producers provide all biomass for the food chain (production of glucose via photosynthesis).
- The rest of the food chain involves the transfer of the biomass.
What piece of apparatus is used to measure the abundance and distribution of organisms in an area ?
Quadrat
What piece of apparatus is used to study the distribution of organisms across a gradient?
Belt transect
When considering the abundance of organisms , what is meant by the term “mean” ?
The average number of organisms
How is the arithmetic mean calculated?
Sum of each number of each organism/ the total number of each type of organism
When considering the abundance of different organisms, what is meant by the term “mode”?
The most populous organism
When considering the abundance of organisms , what is meant by the term “median” ?
The organism that represents the middle value when the numbers of each organism are arranged from lowest to highest