4.7 Organisation of an ecosystem and recycling Flashcards
photosynthetic organisms are known as
producers
Feeding relationships can be represented as a
food chain
all food chains begin with..
a producer
a plant is known as a producer because…
its produces its own food!
Plants make glucose in what process?
photosynthesis
What piece of equipment would you use to estimate population size?
quadrat
What piece of equipment would you use to measure change in distribution of an organism from one area to another?
tape measure - use to make a transect
The mean is
the average - add up all the data and divide by how many you have
The mode is….
the most popular/number that occurs most frequently
The median is
the middle value - once all data has been organised into numerical order
An organism that eats other animals is known as a
predator
Animals that are hunted and eaten by other animals are called
prey
In a stable community what happens to the number of predator and prey?
rises and falls in cycles
carbon is returned to the atmosphere as
carbon dioxide
What process returns carbon dioxide to the atmosphere?
respiration
which process removes carbon dioxide from the atmosphere?
photosynthesis
Which organisms carry out decay?
microbes/micro-organisms
What conditions are necessary for decay?
warmth, moisture, energy source and oxygen
What is biomass?
dry mass, energy store - makes up the living material of all living organisms
The population size of any species is limited by..
food availability
If food availability increases (prey) what will happen to the predator population?
increase
If the predator population increases what will happen to the prey population?
decrease
Predator and prey cycles are always out of phase with each other -what does this mean?
It takes a while for one population to respond to the other population
What does the energy from the sun do to the water on the land and in the sea?
causes it to evaporate and turn to water vapour
Evaporation of water from plants is known as
transpiration
When water vapour evaporates it is carried upwards. What happens to it when it gets higher up?
it cools and condenses to form clouds
Water in clouds falls as rain - what is known as?
precipitation
When rain falls onto the land where does it eventually end up?
drains into the sea
All living things are made up from the elements …
Carbon
hydrogen
oxygen
nitrogen
What biological molecules contain carbon?
carbohydrates, proteins and fats
In a food chain what is passed on?
biomass/energy
What is decay?
breakdown of dead animal or plants by micro-organisms
Why is decay important?
To recycle elements locked up inside dead organisms so that they can be returned to the environment and reused
In a stable community what can be said about the materials taken out of the soil v materials used by the plants?
its balanced
Carbon in carbon dioxide is used to make which carbon molecule?
glucose
glucose contains carbon what molecules is it used to make?
cellulose starch fats proteins THEY ALL CONTAIN CARBON TOO
How does the carbon in plants get into the body of an animal?
feeding
How does the carbon in dead animals and plants end up in the atmosphere?
microbes carry out decay
microbes respire
releasing carbon dioxide back into the atmosphere
How does the carbon in living organisms get returned to the atmosphere?
respiration - returned as carbon dioxide
What other process (not respiration ) ADDS carbon dioxide to the atmosphere?
combustion
a habitat is
a place where an organism lives
The distribution of an organism is described as..
where it is found
The distribution of organisms is affect by..
environmental factors
What is a quadrat?
a square frame enclosing a given area usually 1m2
When sampling plant populations, how should the quadrat be placed?
randomly
How do you decide where to place a quadrat for sampling?
Divide your area to sample into a grid and use a random number generator to pick coordinates
Why should you sample randomly?
avoid bias is data
When sampling with a quadrat why should you do a lot of samples e.g. at least 20
to ensure data is representative
increases reliability
If sampling a field to estimate the population of daisies on the field what will you do when you have sampled the field a minimum of 20 times?
calculate a mean number of daisies per quadrat
How will you estimate the number of daisies on a school field?
- sample randomly
- calculate a mean
- scale this mean up to reflect the size of the field e.g. if 10 daisies per 1m2 and the field is 100m2 - times the 10 by 100 = 1000daisies.
