Topic 7- Ecology Flashcards
what is a habitat
a place where an organism lives
what is a population
all the organisms of one species living in a habitat
what’s community
the populations of different species living in a habitat
what’s abiotic factor mean
non living factors of the environment- eg. temperature
what does biotic factor mean
living factors of the environment- eg. food
what does eco system mean
the interaction of a community of living organisms (biotic) with the non liivng (abiotic) parts of their environment.
what do plants compete for
light, space, water, mineral ions (nutrition)
what do animals compete for
space (territory), food water and mates
what is interdependence
in a community, each species depends on the other species for things such as food, shelter, pollination and seed dispersal
what is a stable community
where all the species and environmental factors are in
balance so that population sizes remain fairly constant.
what can abiotic and biotic factors do in an ecosystem
vary
give some examples of abiotic factors
- light intensity
- temperature
- moisture levels
- soil pH and mineral content
- wind intensity and direction
- carbon dioxide levels for plants
- oxygen levels for aquatic animals
give some examples of biotic factors
- availability of food
- new predators arriving
- new pathogens
- one species outcompeting another so the numbers are no longer sufficient to breed.
what’s an adaptation
Organisms have features (adaptations) that enable them to survive in the conditions in which they normally live
what are the three types of adaptations
structural, behavioural, functional
what’s a structural adaptation
features of an organism’s body structure- eg. shape or colour
what’s a behavioural adaptation
way they behave eg. migration
what’s a functional adaptation
things inside an organism’s body that can be related to a process eg. reproduction and metabolism
what is an extremophile
organisms that live in environments that are very extreme, such as at high temperature, pressure, or salt concentration
eg. bacteria living in deep sea vents
what do food chains start with
the sun and then the producer (these produce their own food using energy from the sun)
usually green pants or algae- make glucose by photosynthesis
what is biomass
when a green plant produces glucose, some of it is used to make other biological molecules in the plant and these biological molecules are the plant’s biomass/
mass of living material
what can biomass also be thought as?
energy stored in a plant
give an explanation of the food chain
Producers are eaten by primary consumers, which in turn may be eaten by secondary consumers and then tertiary consumers.
what are predators
consumers that hunt and kill other animals
their prey are what they eat
give trends of a stable community
- the population of any species is usually limited by the amount of food available
- if the population of the prey increases, then so will the predators
- as the population of predators increases, the population of the prey decreases
why are predator-prey cycles always out of phase with each other?
it takes a while for one population to respond to changes in the other population
eg. if the no. of rabbits inc, then the no. of foxes doesn’t increase immediately, cos it takes time for them to reproduce.
what do environmental changes cause
distrobution of organisms to change
give the three examples of environmental changes that can affect an organism
availability of water- rainfall patterns
change in temp
change in composition of atmospheric gases- air pollution
how are some environmental changes caused
by seasonal factors, geographical factors or human interaction
eg. rise in temp- due to global warming , caused by human activity
why are all materials in the living world are recycled
to provide the building
blocks for future organisms.
what happens in the water cycle
1) energy from SUN makes water EVAPORATE fromt eh land and sea, turning it into WATER VAPOUR. Water also evaporates from plants (transpiration)
2) warm water vapour carried upwards (warm air rises). At higher point, it COOLS and CONDENSES to form clouds
3) water falls from clouds as PRECIPITATION onto land- provides fresh water for plants and animals
4) drains into the sea- whole process starts again
how are elements cycled back to the start of the food chain
by decay
what are living organisms made of
materials they take in from the world around them
explain the role of microorganisms in cycling
materials through an ecosystem
- materials get passed up the food chain
- theyre returned to the environment in waste products, or when the organisms die and decay
- most materials are broken down (digested) by micro organisms
- decay puts mineral ions etc back into the soil
what conditions do micro organisms decay better in
warm, moist aerobic (oxygen rich) conditions- micro organisms are more active
what is decay like in a stable community
materials that are taken out of the soil and used by plants etc are balanced by those that are put back in (constant cycle).
what happens in the carbon cycle
1) Green plants and algae remove CO2 from the atmosphere during PHOTOSYNTHESIS.
The carbon is used to used to make GLUCOSE, which can be turned into carbohydrates, fats and proteins (make up bodies of the plants and algae)
2) when plants and algae respire- some carbon is returned to atmosphere as CO2
3) when plants and algae are eaten by animals, some carbon becomes part of the FATS and PROTEIN in their bodies. THE CARBON MOVES THROUGH THE FOOD CHAIN
4) animals respire- some carbon returned to atmosphere as CO2
5) plants animals algae die- detritus feeders and microorgansims feed on their remains- when they respirs, some CO2 returned to atmosphere.
6) animals also produce waste which is broken down by df.
7) combustion of wood and fossil fuels releases CO2 back into the air.
8) so carbon and energy is constantly being cycled- form the air, through food, algae, animals, dfs and micro organisms- back into the air again.
what is compost?
decomposed organic matter (eg. food waste)- used for natural fertiliser for crops and garden plants.
what do farmers do to get good compost
try to provide the ideal conditions for quick decay (to form compost)
name four factors that affect decay
temp, oxygen availability, water availability, no. of decay organisms
how does temp affect decay
warmer= increased decay- bcos of increased rate of enzymes
too hot= decomposition is slowed down/stopped- bcos enzymes are denatured
really cold- slow decay too
how does oxygen availability affect decay
micro organisms need oxygen to respire
BUT anerobic microorganisms don’t need it
how does water availability affect decay
faster in moist environments- organisms involved in decay need water to carry out biological processes.
how does number of decay organisms affect decay
more microorganisms and dfs = faster decomposition
how is biogas made
by anaerobic decay of waste material
made in a simple fermenter called a digester or generater.
biogas generators need to be kept as a constant temp to keep the microorganisms respiring.
can be stored as a liquid, so has to be used straight away for heating cooking lighting or to power a turbine to generate electricity.
what is biogas
mainly made up of methane- which can be burned as fuel
how do microorganisms produce biogas?
they decay plant and animal waste anaerobically (without oxygen)- this produces methane gas.
can be made on a bigger scale from sewage works or sugar factories
what are the two different biogas generators??
batch- small batch, manually loaded with waste, left to digest.
continuous- all the time at steady rate
what is biodiversity
the variety of different species of organisms on earth, or within an eco system
why is high biodiversity good
makes sure ecosystems are stable; different species depend on each other for things like shelter and food, and physical things such as acidity of the soil
what things reduce biodiversity
waste production, deforestation and global warming
why has human population increased so much recently
modern medicine and farming methods have been introduced
what are the increasing demands on the environment
demanding higher standard of living- cars computers etc
so use more oil and raw materials
and use more energy to make the products
so…
materials are being used up faster than they’re being replaced - we’re going to run out!
how does producing more waste damage the environment
when we produce more waste, more harmful pollution will be caused…
It reduces biodiversity and affects…
water- sewage and toxic chemicals can pollute lakes rivers and oceans, affecting the plants and animals that rely on them for survival. Chemicals used on land can be washed into the water.
land- using toxic chemicals for farming & burying nuclear waste underground & dumping household waste in landfill sites
air- smoke and acidic gases released into the atmosphere- pollute air, sulfur dioxide- can cause acid rain
what happens in global warming
- gases in the atmosphere- insulating layer
- absorb most of energy that would normally be radiated out to space- re radiate it in all directions- this warms the earth
- getting out of hand, greenhouse gases (CO2 and methane mainly) are rising sharply.
- can cause other types of climate change eg. rainfall patterns
What four things are worrying about global warming?
- seawater expands, ice melts- sea levels rise- flooding - loss of habitat
- rainfall patterns change- wild animal and plant species change- change in how wildly distributed they are
- changes in migration patterns in eg. birds
- biodiversity reduced- climate change leads to extinction of certain species
how do humans use land
- building, quarrying, farming, dumping waste
- less land available for other organisms
- deforestation or destruction of habitats like peat bogs and other areas of peat.
what is deforestation and why is it done
cutting down of forests
- to clear land for farming to provide more food
- to grow crops form which biofuels based on ethanol can be produced
what three major problems can global warming cause
less CO2 taken in- trees lock up some carbon during photosynthesis in their wood
more CO2 in atmosphere- released when trees are burnt to clear land, microorganisms feeding on dead wood- releases CO2 as a waste product of respiration
less biodiversity- when destroyed- habitats destroyed- more likely for species to become extinct.
what are peat bogs?
bogs- areas of land that are acidic and waterlogged
plants that live in bogs don’t decay fully cos there isn’t enough oxygen.
partly rotted plants build up to form PEAT
so carbon is stored there from the plants
how is carbon dioxide produced from peat?
peat is drained- contact with air- some microorganisms begin to decompose it; when they respire, release CO2
CO2 released when peat is burned
what is peat used for?
drained so area is used for farmland
peat is cut up and used for fuel
sold to gardeners for compost
what does destroying peat bogs reduce
biodiversity
give some examples of programmes which have been set up to maintain biodiversity…
breeding programmes- animals are bred in captivity to make sure species survives if it dies out in the wild.
protection of rare habitats (mangroves, heathland, coral reefs)- helps preserve species that live there.
reintroduce hedgerows and field margins around fields on farms where only a single type of crop is grown- increases amount of wild flowers, grasses and provides habitat for wider range of organisms.
restrictions on deforestation and amount of business CO2.
people are encourages to recycle- reduces land fil- reduces loss of habitat.
name some conflicting pressures over how biodiversity is maintained…
costs money- paying farmers to introduce hedgerows and keeping an eye on whether people are following programmes- money may be prioritised.
tree-felling industry unemployed
conflict between biodiversity protection and food secturity- eg. pests are killed to save crops
development- eg. building houses on land
what are the different trophic levels
Level 1: Plants and algae make their own food and are called producers.
Level 2: Herbivores eat plants/algae and are called primary consumers.
Level 3: Carnivores that eat herbivores are called secondary consumers.
Level 4: Carnivores that eat other carnivores are called tertiary
what are decomposers and what do they do
Decomposers break down dead plant and animal matter by secreting
enzymes into the environment. Small soluble food molecules then
diffuse into the microorganism.
what are pyramids of biomass
Pyramids of biomass can be constructed to represent the relative
amount of biomass in each level of a food chain. Trophic level 1 is at the
bottom of the pyramid.
how is biomass transferred in a food chain
producers such as green plants and algae use energy from the sun to carry out photosynthesis- this produces glucose
only 1% of energy that hits the producers is transferred for photosynthesis
some glucose is used to make biological molecules
biomass stores energy and only 10% of biomass is passed on to the next trophic level in a food chain
why is biomass lost between the levels?
organisms don’t eat all the organisms they’re consuming - eg. bone, so not all biomass is transferred
not all biomass is absorbed, some is egested (released) in faeces.
some biomass that is taken in is converted in to other substances that are lost to waste - eg. organisms use lots of glucose in respiration to provide energy for movement and keeping warm rather than making more biomass…
…this produces lots of waste CO2 and water as by-products.
…urea is another waste substance, which is release in urine with water when the proteins in the biomass are broken down
what’s the equation of efficiency of biomass transferred between trophic levels…?
efficiency= biomass transferred to next level divided by biomass available at previous level x 1000
what is food security?
Food security is having enough food to feed a population
name some biological factors that are having an effect on food security…?
- the increasing birth rate has threatened food security in some countries
- changing diets in developed countries means scarce food resources are transported around the world
- new pests and pathogens that affect farming
- environmental changes that affect food production, such as widespread famine occurring in some countries if rains fail
- the cost of agricultural inputs
- conflicts that have arisen in some parts of the world which affect the availability of water or food.
how can the efficiency of food production be improved
by restricting energy transfer from food animals to the environment.
This can be done by limiting their movement and by controlling the temperature of their
surroundings.
Some animals are fed high protein foods to increase growth.
what MUST happen concerning food security?
Sustainable methods must be found to feed all people on Earth.
what’s happening to fish stocks in the oceans and why is it important to keep fish stock levels high?
they’re declining
It is important to maintain fish stocks at a level where breeding continues OR certain species may disappear altogether in some areas.
What play important roles in conservation of fish stocks at a sustainable level?
Control of net size and the introduction of fishing quotas
what is modern biotechnology and what can it do?
Modern biotechnology techniques enable large quantities of microorganisms to be cultured for food.
what is mycoprotein and how is it made?
used to make high protein meat substitutes- “QUORN”
made from fungus, Fusarium, which is grown in aerobic conditions, feeding off glucose syrup
harvested and purified- producing mycoprotiein
how can bacteria be modified to produce human insulin?
1- plasmid (loop of DNA) is removed from a bacterium
2- insulin gene is cut out of human chromosome using a restriction enzyme- leaves DNA strand with unpaired base- ‘sticky end’
3- plasmid is cut open using the same restriction enzyme, leaving same sticky end together.
4- plasmid and human insulin gene are mixed together
5- ligase is added- this joins the sticky ends together to produce recombinant DNA
6- recombinant DNA is inserted into a bacterium
7- bacterium is grown inder controlled conditions in a vat.
8- insulin bacteria reproduce - can be harvested and purified to treat people with diabetes
What could genetically modified crops do
resistant to pests- improving crop yields.
grow better in drought conditions.
more nutritional value - ‘Golden Rice’ lots of vitamin A.
why doesn’t everyone agree with gm crops?
- they say tackle poverty first.
- countries may become dependent on countries selling GM crops.
- poor soil- even gm crops won’t survive in the conditions.
