Ecology and the Environemnt Flashcards
What is population?
The number of organisms of one species in a habitat.
What is a community
All the different species in a habitat
What is a habitat
The space or area in which an organism lives.
What is an ecosystem
An area where non- living and living things interact together.
How can you estimate the population size of an organism in different areas?
- Randomly throw a quadrat on the ground.
- Count all the organisms within the quadrat.
- Repeat 5 times and find the mean.
- Multiply this number with the size in m^2 of the investigated area.
- Repeat for other areas.
How can quadrats be used to sample the distribution of organisms in their habitats?
Mark out a line along the area you want to investigate.
Using quadrats, collect data along the line.
What are producers
Organisms that make their own food
What are primary consumers
Organisms that usually eat plant material (herbivores)
What are secondary consumers
Organisms that usually eat animal material (usually carnivores)
What are territory consumers
Carnivores, but at the top most level in the food chain
What are decomposers
Mainly fungi and bacteria. They break down dead animal and plant material and use the nutrients from it by respiration.
What is a food chain
A simplistic representation of a situation in an ecosystem.
What is a food web?
A complex representation of a situation in an ecosystem that takes into account the different feeding preferences of animals.
What are pyramids of numbers
A pyramid drawn to scale to show the population of each organism.
What are pyramids of biomass
A pyramid drawn to give a more accurate indication of how much energy is passed on at each tropic level.
What is biomass?
The dry mass of living material in each organism.
What are pyramids of energy transfer?
A pyramid that represents estimates for energy values with producers in the lower layer up to the consumer in the top layer.
What happens when one thing consumes another in terms of energy?
The substances within it (e.g. Fat) get transferred to the consumer.
Pyramids have wide bases and eventually decrease in width as energy has been lost. Why is this?
- material is not eaten by the consumer?
- material is not digested by the consumer, and is therefore passed out as waste.
- energy is used by the consumer for movement
- energy is used for metabolic processes (e.g. Respiration)
- energy is used in generating heat
- energy is lost in urine.
What is evaporation and how does it contribute to the water cycle?
This happens to water on wet surfaces and bodies of water and turns it into water vapour which goes in to condense to clouds.
What is transpiration and how does it contribute to the water cycle?
The loss of water from plants as it evaporates from the surface of vegetation. It forms water vapour which then condenses to form clouds.
What is condensation and how does it contribute to the water cycle?
Water vapour in the atmosphere condenses to from clouds, fog, frost etc.
What is precipitation and how does it contribute to the water cycle?
Water vapour is held in the formation of clouds, fog and frost. Some falls into the ground and forms rivers and streams or is taken up by plants.
What is combustion and what is its relation to the carbon cycle?
The burning of materials derived from plants, which releases co2 into the atmosphere. This is then used by plants to photosynthesise.
What is photosynthesis and what is its relation to the carbon cycle?
A metabolic reaction in green plants that uses light energy to make energy. It takes in co2.
What is respiration and what is its relation to the carbon cycle?
A metabolic reaction that releases energy and carbon dioxide gas. The energy released is used for growth and repair.
What is decomposition and what is its relation to the carbon cycle?
A process where bacteria and fungi break down large molecules into smaller molecules when organisms dies. They respire and produce co2.
What do nitrogen fixing bacteria do in the nitrogen cycle?
They convert nitrogen in the air into nitrates so that plants can use them to make amino acids and proteins.
What do decomposers do in the nitrogen cycle ?
Break down dead animal and plant matter, releasing nitrogen as ammonia.
What do nitrifying bacteria do in the. Nitrogen cycle?
Convert ammonia into to nitrites, nitrites into nitrates and or ammonium ions.
What do denitrifying bacteria do in the nitrogen cycle?
Reconvert nitrates back into nitrogen gas = decreasing valuable resources in the soil.
What are the biological consequences of sulphur dioxide?
- So2 in combustion of fossil fuels= dissolves in water= acid rain- low pH: fish pop has decreased and sticky mucus on gills= less gas exchange.
- acidified lakes= loss of algae in water= alters balance of species.
- many trees and plants have died/ had poor growth due to acidic soil.
- acid rain= crumbles buildings
What are the biological consequences of carbon monoxide?
- car exhausts and cigarette smoke= co= poisonous gas that reduces the blood’s oxygen carrying capacity.
- prevents formation of haemoglobin= less o2 transported= cell death
Give examples of green house gases? (5)
Water vapour Carbon dioxide CFC's Nitrous oxides Methane
How is co2 formed and what is its effect?
Burning of fossil fuels= factories and power stations
Deforestation= less uptake of CO2 and therefore upsets balance between photosynthesis and respiration
How is methane formed and what is its effect?
Cattle and other ruminants= digestion= methane
Rice paddy fields= produced by bacteria in anaerobic conditions
Decay of waste material= methane released
How are CFCs formed and what is its effect?
CFC (11)- aerosol sprays= made by humans from fridges and aerosol cans
CFC (12)- cooling agent.
How are nitrous oxides formed and what is its effect?
Fossil fuels/ motor exhausts= catalytic converters have been fit
Nitrogen fertilisers= nitrates in soil are converted to NOx and N2by denitrifying bacteria
What is the greenhouse effect?
- Electromagnetic radiation is emitted from the sun into the earth’s atmosphere
- earth absorbs electromagnetic radiation with short wavelengths and so it warms up.
- Heat is radiated from Earth as longer wavelength radiation
- sine if this is absorbed by greenhouse gases=warmer
- more greenhouse gases= warmer earth*
What are the effects of global warming?
- rise in temp= ice caps melting, flooding and sea level rise.
-loss of habitat
-disruption to food chain as organisms die
-migration of animals - desertification
- severe climate changes
What are the biological consequences of water pollution by sewage?
If sewage enters a lake= increase in nutrients especially as microorganism will break the sewage down to even more nutrients.
= increased nutrients stimulate rapid growth and multiplication of algae.
What is sewage?
The domestic waste material from human communities. It contains human urine and faeces and phosphates and nitrates.
What happens when there is an increase in algae?
There are more life cycles= more deaths.
More deaths=more decomposition=more nutrients for microbe respiration.
More respiration= more oxygen required= higher BOD.
Higher BOD= less oxygen available so aquatic animals suffocate and die.
- or more algae= more shade so plants die.
What is eutrophication?
The enrichments of the water which can happen due to leached minerals from fertilisers or from sewage.
What are the effects of deforestation?
-Leaching: less trees= less water is held back to water runs off, taking mineral ions with it.
-Soil erosion: top soil is removed or washed away so soil is directly exposed to wind and rain. -*less trees= loss of soil structure and fertility.
Disturbance of water cycle= much more unabsorbed water= flooding and landslides.
-imbalance of o2 and co2: less co2 absorbed for photosynthesis and more is released from burning the trees= enhances greenhouse effect
Less o2 is produced= respiration problems.
What is a greenhouse gas?
Gases that trap heat and contribute to global warming.
