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
What is the method in which decomposers release carbon dioxide into the air
Respiration
What is respiration and how does it release carbon to the atmosphere
A process which uses chemical reactions to break down glucose molecules to make energy
Once it has broken down glucose, it releases carbon dioxide
What biological compounds that are present in animals is nitrogen present in (4)
Dna, ATP, vitamins, proteins
What is the percentage composition of the air with the three major gases
78% nitrogen, 21% oxygen, 0.9% Argon, 0.04% Carbon dioxide
What is the product that decomposers break down from Urea, and what can it form
Ammonia, which can form nitrite, which case form nitrates
What are the two places that nitrogen fixing bacteria live
1) free in the soil
2) in the nodules of the roots of legumes
Nitrifying bacteria converts what to what
Ammonia to nitrites
Nitrates are absorbed in the roots of plants and joined with what else present in the plant to make what
along with carbohydrates from photosynthesis, to make amino acids
Explain Where animals get nitrogen from and what they use it for
animals eat the plants
The animals then use this for proteins and DNA
Why can plants not absorb nitrogen directly
Because it is unreactive
Explain what mutualism is and give an example
Mutualism is when two organisms benefit from the relationship. An example is how nitrogen fixing bacteria make ammonia for the plant which it uses to make amino acids , and in return the plant provides the bacteria with organic nutrients
Which two processes return nitrogen to the soil as ammonia
Death and decomposition
What are the four types of bacteria in the nitrogen cycle and their jobs
1) nitrogen fixing bacteria, convert atmospheric nitrogen into ammonia
2) nitrifying bacteria, convert ammonia into nitrates
3) denitrifying bacteria convert nitrates in “waterlogged” soil to nitrogen in the air
4) decomposers break down nitrogen from proteins and convert them to ammonia in the soil
Explain why a peat bog is a carbon sink
- has low levels of oxygen
- so bacteria who require aerobic conditions are unable to decompose dead matter quickly
-therefore the carbon in these dead organisms piles up
what are humans making demands on the environment for (5)
-food to supply growing population
-fuels to heat homes
-space for living
-space for waste
-materials to build homes
How is nitrogen removed from a farm
-When crops and livestock are sold(nitrogen in their proteins)
Why do inorganic fertilizers increase eutrophication but organic fertilizers do not
Inorganic fertilizers contain soluble nitrogen compounds which are easily leached, howver organic fertilizers contain insoluble nitrogen compounds so are leached less quickly
Why is there more carbon dioxide in the winter than in the summer
Trees lose their leaves in the winter, so cannot photosynthesize
-they still respire however so release carbon dioxide but do not remove any
-however in the summer months, trees have leaves so can absorb a lot of CO2
-trees photosynthesize faster than they respire so more carbon is removed
Why is the normal greenhouse effect good
-it allows enough heat to be contained in the atmosphere for life on earth. Otherwise heat would be lost to space
Pollution (definition)
Contamination of the environment
by harmful substances
that are produced by human activities
What is a greenhouse gas
A gas that absorbs infrared radiation from the sun
5 greenhouse gases and where they come from
Carbon dioxide- fossil fuels, respiration, decomposition
Methane- landfills, agricultural activities(part of digestion)
Water vapor- clouds
Nitrous oxide- combustion in cars
CFCS-aerosol sprays
How can you investigate the amount of carbon dioxide from the past
Look into ice cores as they contain bubbles of trapped CO2
What are four reasons for global warming
-deforestation- as trees remove carbon from the atmosphere during photosynthesis thus more carbon in the atmosphere
-waste buildup-causes methane buildup
-increased agriculture
-burning fossil fuels
Explain how the greenhouse effect works
1) the sun emits short wave radiation into the atmosphere
2) the earths surface absorbs this energy
3) the earths remits this energy as long wave radiation(infrared heat)
4) some of this emmitted heat is lost in space
5) the rest is trapped by greenhouse gases in the atmosphere, causing global warming
what is absorption in the nitrogen cycle
When the root hairs of plants absorb nitrates from the soil, which the plant uses to make proteins
Explain how nitrogen is released into the soil through excretion
Animals release nitrogen that they can not absorb as urea. Decomposers break down this nitrogen into ammonia which is released into the soil.
Faeces contain undigested proteins which are absorbed by the soil
Describe 5 ways in How nitrogen can enter the soil
Nitrogenous fertilizers
Lightning
Nitrogen fixing bacteria
decomposition of dead plants or animals
Excretion
4 consequences of the greenhouse effect(5(
-ice caps will melt, due to increase heat, so sea levels will rise
-ocean currents will change, cool water will turn warm, affecting marine species
-higher temperatures increase the rate of evaporation, so more water vapor in the atmosphere means more precipitation
-higher temperatures, increases rate that pests grow, so pests increase which can decrease crop yield
-if animals can not adapt quickly enough to the warmer environment, they could become extinct
Describe where methane comes from (3)
-decomposition of waste in landfill sites
-fermentation in the stomach of ruminants
- fermentation of rice fields
Where does carbon monoxide come from and how is it fatal
-Combustion of car engines
- to humans as it binds to haemoglobin quickly, reducing oxygen to the cells, causing heart and brown to stop working
What are the two gases that cause acid rain
Sulfur dioxide, nitrogen oxide
Explain how sulfuric acid is formed
fossil fuels such as coal or oil are burnt releasing sulfur dioxide, then dissolves in rain water to form sulfuric acid
Why is rain already naturally acidic
Because it combines with carbon dioxide in the air
How does nitric acid form
When fossil fuels are burnt and then dissolve in rain water, or from the combustion of car exhausts
4 consequences of acid rain
-makes waters more acidic so can be harmful to marine ecosystems
-decreases ph of soil, which deprives it of nutrients
-can corrode buildings
-increases aluminum so more difficult for trees to absorb water
How does burning of nitrous oxide leach nutrients out of soil
Nitrous oxide forms nitric acid when dissolved in rainwater. Enters waters and streams
How can you monitor the level of pollution by sulfur dioxide
Observe patterns of lichen growth as they are tolerant to sulfur dioxide levels
Explain 4 different ways in how deforestation could affect the environment (4)
-Soil erosion: tree roots can no longer hold soil in place, so soil washes away
-Leaching: trees no longer provide a canopy so soil is exposed and when rainwater falls as runoff it takes all the nutrients of the soil along with it
-extinction of species as habitat is destroyed
-more carbon dioxide in the atmosphere as no photosynthesis ,more oxygen , and trees are often burnt which produces even more carbon dioxide
What is sewage
Wet waste from homes, farms, and factories that contains dissolved organic and inorganic chemicals
What happens if sewage is untreated
1)Aerobic bacteria begin to decompose the organic material so reduce the amount of oxygen in the water
Other fresh water organisms can not survive
2) It contains pathogenic bacteria which can be harmful for humans
Explain how water pollution levels can be indicated
By using insects, where blood worms indicate high levels
, cadis fly larva indicate moderate and stone fly lymph present low levels
why does nitrate get washed into waters
Because it is soluble in water and can easily be washed out of the soil
Explain the process of eutrophication (5)
1) mineral ions and nutrients from fertilizer run off enter the water
2) There is rapid algal bloom as algae takes all the nutrients to stimulate its growth
3)Rate of photosynthesis decreases because sunlight can not reach other plants and so oxygen levels decrease
4) algae die and aerobic bacteria begin to decompose the dead organic material, depleting oxygen from the water
5) water becomes anoxic and so organism die due to this lack of oxygen
What is the effect of suspended solids in rivers for water plant life
Suspended solids make the water cloudy so less light can reach the plants for photosynthesis and they will die
Explain how you can increase the productivity of cows at an indoor farm
Keep them in a warm temperature so that they do not need to lose heat energy to maintain a constant body temperature
What is meant by the term decompose:
Process where organisms SUCH AS BACTERIA break down organic material to simpler organic compounds by releasing carbon dioxide
why two fish of the same size may produce different masses of nitrogenous waste
they may eat different SPECIES of fish
Suggest why the cows absorb a lower percentage of energy from the food it eats than the fish (2)
1)Because the grass is large and the cow won’t be eating all of the energy whereas the fish will eat all of the energy
2) Fish has a larger surface area to ratio volume so energy is lost faster, thus it needs to gain more energy
Explain two reasons how by placing black plastic on plants can increase the rate that they grow at
1)help to retain moisture so that it is not lost by evaporation
2)prevents access to pests
Explain two ways in how deforestation can affect the carbon cycle
1)more carbon dioxide released into the air because less photosynthesis to remove
2) trees are often burnt which releases stored carbon from the trees
Why can a marine ecosystem contain five trophic levels
Because there is a large amount of photosynthesis thus a large amount of energy can be transferred throughout the food chain
Explain why malaria in Europe is more likely to spread from global warning?
Because mosquitoes who live in warmer areas will be able to spread to other warmer areas as the become hotter
First step of eutrophication in terms of nitrates
Nitrates are leached from the ground into the rivers because they are soluble in rain water
In the food chain: nettle—-) caterpillar—) raccoon, suggest why the number of caterpillars may decrease in the winter
Because they may turn into a caccoon
Or nettle population may decrease so they will decrease consequently
How can countries limit the impact of deforestation (2 ways)
-place laws to limit deforestation
-plant more trees
Give three abiotic factors that can affect plant growth
-temperature
- sunlight
- carbon dioxide
(Could also mention water, salinity and nutrients)
Apart from predation, what two other biotic factors affect pest growth
Competition of resources, disease
Three abiotic factors that may affect pest growth
-temperature
-water content
-pesticide
:
Why does raw sewage have a higher biological oxygen demand than treated sewage
Because it contains more organic waste material that needs to be decomposed, thus more oxygen is needed in order for micrograms to respire to break it down
Explain why algal bloom increases with temperature
Algae are photosynthetic organism so and increase in temperature increases photosynthesis rates, thus increasing rate at which they grow
Why is more oxygen depleted from sewage with smaller pieces, rather than sewage with larger pieces
Smaller piece means larger surface area to volume ratio so higher rate of decomposition
Explain how chemical fertilizers increase crop yield
-Potassium present is needed in enzymes involved in respiration and photosynthesis
-Phosphorus is needed to make DNA and cell membranes
-Nitrates are needed to make amino acids for proteins which are needed for cell growth
-Sulphuric is also needed to make protein which helps growth
Suggest three reasons why there are fewer cases of bovine tuberculosis in cows in Europe than out of Europe
1)population of Europe is small compared to rest of the world
2)Europe may have more vaccinated cows than other parts of world
3) or more cattle are given antibiotics in Europe than in rest of world
Suggest two ways that badgers can benefit from territorial behaviour(protecting its territory, not letting others enter)
1) Less completion for resources for mates
2)les competition for resurfaces of food
