Ecology Flashcards
(48 cards)
Define population
All the organisms of one species that live in the same ecosystem as the same time
Define community
All the populations of all the species that live in the same ecosystem at the same time
Define habitat
The place where an organism lives
Define ecosystem
A distinct, self supporting system of biotic organisms interacting with each other and with the physical, abiotic environment
Define abiotic
Non living components in a ecosystem
Define biotic
Living components in an ecosystem
Define biodiversity
The amount of variation shown by organisms interacting within an ecosystem. The measure of the number of species and the abundance of species
What abiotic factors affect population size
Weather can freeze of heat animals too much, PH and temperature affects enzymes, oxygen affects the rate of respiration
What biotic factors affect population size
Predators reduce population, diseases caused by pathogens reduce population
What are the five tropic levels in order
Producers, primary consumers, secondary consumers, tertiary consumers, decomposers
What is an example of a producer
Grass
What is an example of a primary consumers
Cricket
What is an example of a secondary consumer
Frog
What is an example of a tertiary consumer
Snake
What are two examples of decomposers
Fungi, bacteria
Define a food chain
A food chain shows how energy is transferred between organisms
How is a food chain unrealistic
They oversimplify feeding relationships as it implies that every organism only feeds on one other organism
What is a food web
A group of inter-locking food chains
Why are food webs more realistic than food chains
Plants and animals are eaten by more than one species
What is a pyramid of numbers
-each bar on the pyramid shows the number of organisms at that stage of the food chain
-the producer goes at the bottom as it is at the bottom of the food chain
-in a typical pyramid of numbers, every time you go up a trophic level the number of organisms goes down as it takes a lot of food from the level below to keep the animal alive.
-however in some cases it may not be a pyramid eg 1 fox feeds 500 fleas
What is a pyramid of biomass
Each bar on a pyramid of biomass shows the mass of living material at that stage of the food chain. Eg one fox would have a very big biomass and the 500 fleas would have a very small biomass. They are practically always pyramid shaped
Why is a pyramid of biomass a pyramid shape
The biomass contains the energy. As energy is lost between trophies levels so is the biomass
What is a pyramid of energy transfer
Represent the amount of available energy at each level in the food chain
If a food chain is parasites where is the parasite shown on the pyramid
At the top
