Organsims in the environment Y9 Flashcards
What is the definition of the Ecosystem?
A group of interrelated organisms and their physical environment in a particular area e.g. pond, desert etc. The biotic and abiotic components interact with each other
What is the definition of Population?
The numbers of one particular species living in an area at the same time.
What is the definition of Community?
The populations of all species in an ecosystem at any one time
What is the definition of Habitat?
The place in which an organism lives
What is Ecology?
The study of the relationship between organisms and their environment
What is Abiotic Factor? and examples?
The non-living physical conditions in an ecosystem e.g. light intensity, temperature, rainfall
What is Biotic Factor? and examples?
The effects of the activities of living organisms on other organisms e.g. food availability, predation, competition, disease
What is a trophic level?
the position in a food chain/food web/pyramid e.g. producer or primary consumer
What is a food web?
a network of interconnected food chains showing the flow of energy through an ecosystem
What do the arrow in the food chains show?
The arrows in food chains and food webs shows the flow of energy
What is the advantage on feeding on more than one organism?
Survive if an organism dies out
Supply for different seasons
Easier to find prey
How can we estimat ethe population of a forest etc:
Using quadrats.
How do we use Quadrats?
Use a tape measure to determine the area of the field ii. Place quadrats around the whole field. iii. To avoid bias, we must place quadrats randomly. This is NOT done by throwing them, but instead by using coordinates that have been randomly generated. iv. Count the number of plants in each quadrat. v. Multiply up to estimate the population of each species in the whole field vi. To ensure a reliable mean, we must take many repeats.
How much energy is transferred from one trophic level to the next?
10%
Where is energy lost between the Sun and the Producer?
Light energy is not absorbed by chlorophyll
Where is enrgy lost between the producer and the primary consumer?
Excretion by the plant, not all the producer is eaten, egestion by the consumer and heat loss due to respiration
Where is energy lost between consumers?
Excretion by the consumer, egestion, not all the consumer is eaten, heat lost due to respiration, movement
What does the pyramid of Biomass show us?
each bar represents the mass of dry organic material (biomass) at each trophic level.
How can the Biomass be calculated?
This can be calculated by gently warming the fresh mass of organisms at each trophic level (to remove water), and then using a mass balance
Which pyramid(s) will always have a pyramidal shape? Why?
Biomass/energy. Due to excretion, egestion, and not all the organism being eaten, both mass and energy will be lost at each trophic level.
Pyramid of energy?
the width of each bar represents the amount of energy passing through each trophic level.
Eg of Biotic Factors?
Availabillity of food
Predation
Parasitism
Disease
Eg of Abiotic Factors?
Climate, temp, light intensity hours of daylight, soil conditions and pollution, O2 conc. pH.
