ecology Flashcards
population
all the ORGANISMS of a particular SPECIES in a HABITAT at the same TIME
habitat
place where an organism lives
community
all the POPULATIONS of all the SPECIES living in a HABITAT at the same TIME
sample
small representative of entire population
Quadrat
square frame made of metal or plastic used for enclosing a area inorder to sample
ecosystem
system of organisms interacting with each other within a physical environment
Why should you use random sampling (2)
So there is no bias
So that results are representative
Biodiversity
Amount of variation shown by species in an ecosystem
What is a biotic factor
living components that affect an ecosystem
3 limitations of sampling
-difficult to spot all the organisms
-Can be easy to miss some out
-organisms may move into or out of an area
(Sampling is looking at a part of a population and using it it estimate the entire population)
What is a solution for not being able to identify organisms
Use a key
4 Steps to study population size in two different areas
1) Measure the area of the field + create a coordinate grid
2) Randomly generate coordinates (using random number on calculator), at least ten, to be accurate and representative
3) Place quadrants and count the number of organisms. Repeat for each survey area
4) Calculate the population ( total number/ total quadrants area X total area of field)
How would you calculate the population size
(total area of organisms /total area of quadrats) x total area
Abundance
The number of individuals per species
why is a species with high biodiversity less likely to be affected by ecological disaster(4)
1)All species are dependent on each other
2)so if one species is wiped out due to disease
3)Then other species that relied on that for food and shelter will not suffer,
4)Because they will have other sources to gain that food and shelter from
What does high biodiversity ensure and why
Ensures stability within an ecosystem as it reduces species dependence on each other
What two components is bio diverts made up of
-Species richness (the number of different species)
-Relative abundance( the number of individuals in each species)
Difference between species richness and biodiversity(3)
Species richness is the number of different species
But biodiversity is the amount of variation in a species
- consists of the species richness and the relative abundance
How can you measure abundance and explain what it is
By measuring the density , which is measuring the number of individuals per quadrat
Abundance: the number of organisms in a species and the evenness of their distribution (so the relation to show how common they are between other species)
Explain how you would investigate the distribution of species across a footpath(4)
2)Use systematic sampling by laying a transit across the area and placing quadrats in intervals
3)Will measure species richness by calculating the frequency, (the presence or absence of a species)
3) will also take some abiotic factors such as light intensity
4)Will use a key to help identify species
Why do plants produce more carbon dioxide in the dark (3)
They are unable to photosynthesis in the absence of light
so produce less oxygen
They therefore produce more carbon because they are still able to respire
5 Biotic factors that can affect distribution
Availability of mates
Predation
Paratism
Competition of resources
Food availability
7 abiotic factors
Soil PH
light intensity
mineral nutrients
soil salinity
Water content
Concentration of oxygen
Pollution
Flow rate
What are three examples of how organisms in an environment interact with each other and examples
- Competition of resources(among compete for mating)
-Feeding amongst them(carbon from plants is recycled by animals)
-interactions with environment (plants absorb c02 for photosynthesis)
when should you use a belt transect instead of a quadrat
When you want to identity trends or patterns across a specific area
why does biomass exclude water content
Because water content varies within organisms depending on environmental factors
Why are marine pyramids inverted
Because the producers-phytoplankton,
have shorter life spans than terrestrial producers such as grass as they reproduce rapidly,
And pyramids of biomass refer to the collective mass at a specific moment in time
So the total biomass is thus less
What is a primary consumer(2)
An animal that eats the producer, and is a herbivore
What is a tertiary consumer
A carnivore that feeds on other secondary consumers
Why can food webs not be so sufficient? (2)
Don’t give information about the mass, don’t give information about the decomposed
2 readings why it is an advantage if an animal can feed on more than one type of organism
1)They can have a balanced diet, due to different nutrient compositions
2) will always have food
Why is a vegetation diet more efficient
less stages in the food chain where energy can be lost
What two carbohydrates are used in chemical energy
Starch and cellulose
5 reasons that energy can be lost
-by movement, respiration
-as heat loss
-not absorbed so undigested
-not all parts are consumed as they are inedible
-form excretory products
Explain why farming cattle indoors is more energy efficient than farming cattle outdoors (3)
Less movement, so less energy is wasted
Will be able to maintain body temperature, so less heat energy is wasted
Will be provided with more food so less energy is needed for growth
How can you measure energy efficiency formula
Energy at next trophic level/ energy at previous tropic level x 100
Why might all the energy from the sun not go to a plant
-may not be able to absorb all wave lengths
-may be lost in respiration
Describe how you will test that respiration causes heat energy through seeds
1) place germinating seeds and dead seeds in a beaker with thermometer
2) germinating seeds temperature will rise as they are respiring
Why is a pyramid of bio mass, pyramid shaped
Not all of the materials are digested
so smaller amounts of biomass are available for growth
When can energy in an organism be fixed
If used for producing new cells
If the tertiary consumer is parasited, where will the parasites appear on a pyramid of bio mass and what will its size be
On the highest level
but will be smallest as their biomass must be smaller than the organism that they parasite
What is the role of decomposers within energy transfer
They break down organic molecules of dead organisms
Produce nutrients which are recycled into the soil
When referring to carbon in microorganisms ——) carbon in fossil fuels, what is the process?
and when referring to carbon in plants——) carbon in decomposers what is the process
1) fossilization
2) decomposition