B3 - Ecosystems And Interactions Between Organisms Flashcards
List the four different levels of ecosystem organisation.
Individual
population
Community
Ecosystem.
What is a habitat?
A place where an organism live e.g a rocky shore or a field
What is a species?
A group of similar organism that can reproduce with each other to give fertile offspring.
In ecosystem, explain the individual level of organisation?
A single organism
In ecosystem, explain the population level of organisation.
All the organisms of one species in a habitat
In ecosystem, explain the community level of organisation.
All the organisms (different species) living in a habitat
In ecosystem, explain the ecosystem level of organisation.
A community of organisations along with all the non-living (abiotic) conditions
Organism need things from their environment and other organism in order to survive and reproduce. List the things a plant needs. (6)
Light Space Water Minerals from soil Seed dispersers Pollinators
Organism need things from their environment and other organism in order to survive and reproduce. List an animal needs. (5)
Space (territory) Shelter Food Water Mates
What is the size of a population limited by?
Competition for resorted and predation
Why is the population of red squirrels decreasing?
Competition with grey squirrels for resources in some areas mean that there isn’t enough food for red squirrels
Who do organism compete with for resources?
Other species and member of other species.
Name the two types of factors that cause change in the environment.
Abiotic (non-living)
Biotic (living)
How can changes in the environment affect communities in different ways? (3)
Some species population size may increase, for others it may decrease or the distribution of population may change.
List abiotic environment conditions that effect communities. (4)
Temperature
pH
Moisture level
Light intensity
What is bioaccumulation?
At each stage of the food chain concentration of toxins increases, so organisms at the top of the food chain receive a toxic dose.
How can expensive fertilises affect lakes and ponds
Excessive fertilisers cause increased growth of algae. The algae blocks the sunlight from plants which die. Microorganisms feeding of the dead plants use up the O2 in the water leading to the death of other organism e.g fish
What is eutrophication?
The release of excessive fertilisers in to ponds and lakes causing increase growth of algae
List biotic environment conditions that effect communities. (4)
Availability of food
Number of predators
Presents of pathogens
Presents of competitors
How does the availability of affect communities? (Black birds)
E.g. in a Bumper year for berries, the population of black bird might increase because there will be enough food for all of them so they are more likely to survive and reproduce.
How does the number of predators effect communities? (Lions)
E.g. if the number of lions (predator) decreases then the number of gazelles (pray) might increase because fewer of them would be eaten
How does the presents of pathogens effect communities?
If a new pathogen is introduced into the community then population may decrease due to illness.
How does the present of competitors affect communities?
Competition for food, water and space
Give two abiotic factors that could effect the community in an ecosystem. (2 marks)
pH level Temperature Moisture level Light intensity Toxic chemicals (One mark per listed effect)
