5.3 Flashcards
Density
density is the number of a particular organism per square metre.
Distribution
where individuals are spread or arranged across an area.
Habitat
the name given to a place where an organism lives
Ecosystem
A dynamic system of organisms that interact with each other and the environment
Abiotic factors
the non-living components of an ecosystem, such as water, temperature, light and pH.
Biotic factors
The living or dead components of an ecosystem
Transects
A sampling method used to estimate the population of wild animals.
Difference between ecosystem and habitat
An ecosystem consists of many communities of organisms that interact with each other and their environment. A habitat is an area where a species lives within an ecosystem.
Quadrat-sampling methodaqcf
Quadrats are a sampling method that is used to measure the population of organisms that don’t move or move very little l
eg. starfish, mussels, clam fish
What organisms would the quadrat sampling method be best suited to
Plants
Capture recapture method
used to estimate the size of a population where it is impractical to count every individual
Why is the capture recapture method less effective for larger animals
Larger animals tend to live in smaller populations or spread over a very large area
why do scientists need to determine a species population
to conserve species
What does regular sampling of populations do
provides information about increases
and decreases in population numbers.
Types of sampling
quadrats
transects
capture-recapture method
How do you estimate the average density of a total area
Estimated average density=
total number of individuals counted/number of quadrats x area of each quadrat
When are transects useful
when the environmental conditions vary along the
sample under investigation);
How to find the total population using capture recpature method
The number caught and marked x the total number recaptured/ the number marked that are recaptured
Describe the relationship between predator and prey populations.
As the prey population increases, there is more food for predators
As the number of predators increases, more prey are captured.
why does a energy pryamid only have 3 or 4 trophic levels.
food chain’s length is restricted to just 3 or 4 steps due to energy loss
Environment
Environment refers to the type of area where an organism lives such as an aquatic or humid environment.
Describe symbotic vs non symbotic relationships
Symbiotic relationships are close physical relations between two different species over a long period of time in which at least on species benefits. eg. mutalism and commensalism.
In non symbotic relationships, neither species have to benefit eg. competition and predation.
