19. Organisms & Their Environment Flashcards
Producers definition
organisms that produce their own organic nutrients usually using energy from sunlight, Plants are producers as they carry out photosynthesis to make glucose
herbivore definition
an animal that gets its energy by eating plants
carnivore definition
an animal that gets its energy by eating other animals
primary consumers definition
herbivores - they feed on producers (plants)
secondary consumers definition
predators that feed on primary consumers
tertiary consumers definition
predators that feed on secondary consumers
decomposers definition
bacteria and fungi that get their energy from feeding off dead and decaying organisms and undigested waste (such as faces) by secreting enzymes to break them down
What does a food chain show?
A food chain shows the transfer of energy from one organism to the next, starting with a producer
What is the source of all energy in a food chain?
The source of all energy in a food chain is light energy from the Sun
What do the arrows in a food chain show?
The arrows in a food chain show the transfer of energy from one trophic level to the next
How is energy transferred from one organism to another?
Energy is transferred from one organism to another by ingestion (eating)
What is a food web?
A food web is a network of interconnected food chains
Why are food webs more accurate than food chains?
Food webs are more realistic ways of showing connections between organisms within an ecosystem as animals rarely exist on just one type of food source
What do food webs give us more information on?
Food webs give us a lot more information about the transfer of energy in an ecosystem
What type of relationship does a food web show?
interdependence
interdependent definition
how the change in one population can affect others within the food web
What causes most of the changes in populations?
Most of the changes in populations of animals and plants happen as a result of human impact – either by overharvesting of food species or by the introduction of foreign species to a habitat
Why is human impact on environments so harmful?
Due to interdependence, these can have long-lasting knock-on effects to organisms throughout a food chain or web
What is a trophic level?
Trophic levels describe the position of an organism in a food chain, web or pyramid
Does an animal have to be at only one trophic level? Why?
NO
Animals (known as consumers) can be at different trophic levels within the same food web as they may eat both primary, secondary and / or tertiary consumers
How does energy from the sun flow to the first trophic level?
Energy flows from the sun to the first trophic level (producers) in the form of light
How do producers make use of light energy?
Producers convert light energy into chemical energy and it flows in this form from one consumer to the next
Where is all energy eventually transferred to?
Eventually all energy is transferred to the environment – energy is passed on from one level to the next with some being used and lost at each stage
Is energy flow a cyclical or non-cyclical process?
NON-CYCLICAL
Energy flow is a non-cyclical process – once the energy gets to the top of the food chain or web, it is not recycled but ‘lost’ to the environment
What is energy flow a direct contrast to?
This is in direct contrast to the chemical elements that organisms are made out of, which are repeatedly recycled
(as energy is not recycled)
What has to happen to energy for it to be transferred ?
In order for the energy to be passed on, it has to be consumed (eaten)
Why is not all of the energy from e.g plants passed onto the primary consumer?
However not all of the energy grass plants receive goes into making new cells that can be eaten
Only the energy that is made into new cells remains with the organism to be passed on
Why may an organism not receive all of the energy in a plant?
Even then, some of this energy does not get consumed – for example few organisms eat an entire organism, including roots of plants or bones of animals – but energy is still stored in these parts and so it does not get passed on
In what 4 ways can energy in a an organism be “lost”?
making waste products eg (urine) that get removed from the organism
as movement
as heat (in mammals and birds that maintain a constant body temperature)
as undigested waste (faeces) that is removed from the body and provides food for decomposers
Why are food chains rarely longer than 5 organisms long?
This inefficient loss of energy at each trophic level explains why food chains are rarely more than 5 organisms long
If, for example, an organism would prey on the top consumer, why would this not be efficient?
In order to survive, it would have to:
eat a huge number of them every day to get the amount of energy it needed to survive (are there that many barn owls close together?)
not expend much energy itself hunting them (is this likely?)
How much energy is:
available to the organism at the next level
lost as heat and in undigested materials?
10% of energy available to organisms at the next level to make new biomass
90% of energy lost as heat an in undigested materials
What type of consumer are humans? What does this mean?
Humans are omnivores, obtaining energy from both plants and animals, and this gives us a choice of what we eat
What does humans being omnivores impact?
These choices, however, have an impact on what we grow and how we use ecosystems
Looking at this food chain, why would it be better for humans to eat the wheat, rather than the cow?
wheat → cow → human
wheat → human
Given what we know about energy transfer in food chains, it is clear that if humans eat the wheat there is much more energy available to them than if they eat the cows that eat the wheat
This is because energy is lost from the cows, so there is less available to pass on to humans
Therefore, it is more energy efficient within a crop food chain for humans to be the herbivores rather than the carnivores
What do humans feed animals and why?
In reality, we often feed animals on plants that we cannot eat (eg grass) or that are too widely distributed for us to collect (eg algae in the ocean which form the food of fish we eat)
What does a pyramid of number show?
A pyramid of numbers shows how many organisms we are talking about at each level of a food chain.
What does the width of a box in a pyramid of number suggest?
The width of the box indicates the number of organisms at that trophic level
Does a pyramid of numbers always have to be pyramid shaped? Why?
NO
This is because the size of the organism is also important – one large organism, like the oak tree in the pyramid above, contains enough energy to support many smaller organisms (the insects)
What are two important things to remember when drawing a pyramid of numbers?
You cannot change the trophic level of the organisms – they must stay in the same order as in the food chain with producers on the bottom, followed by primary consumers, then secondary consumers, then tertiary consumers
Generally, the larger an individual organism is, the less of them there are
What does a pyramid of biomass show?
A pyramid of biomass shows how much mass the creatures at each level would have without including all the water that is in the organisms (their ‘dry mass’)
Do pyramids of biomass have to be pyramid-shaped? Why?
YES
This is because the mass of organisms has to decrease as you go up a food chain – if we take our first food chain as an example, it’s impossible to have 10kg of grass feeding 50kg of voles feeding 100kg of barn owls
Why are pyramids of biomass better than pyramids of number?
Pyramids of biomass provide a much better idea of the quantity of the plant or animal material at each level of a food chain and therefore are a better way of representing interdependence within the food chain
Why are there nutrient cycles?
Nutrients such as carbon and nitrogen are not endless resources
There is a finite amount of each element on the planet and as such, they need to be RECYCLED in order to allow new organisms to be made and grow
- In what form is carbon take out of the atmosphere in and what is it used for?
Carbon is taken out of the atmosphere in the form of carbon dioxide by plants to be used for photosynthesis
- Where does the carbon dioxide the plants have absorbed go?
It is passed on to animals (and microorganisms) by feeding
- How is this carbon returned to the atmosphere?
It is returned to the atmosphere in the form of carbon dioxide by plants, animals and microorganisms as a result of respiration
- What is a natural source of carbon in the Earth and how is this formed?
If animals and plants die in conditions where decomposing microorganisms are not present the carbon in their bodies can be converted, over millions of years and significant pressure, into fossil fuels
- How is the carbon in fossil fuels released?
When fossil fuels are burned (the process is known as combustion), the carbon combines with oxygen and carbon dioxide is released into the atmosphere
What is an increased use of fossil fuels causing?
Increased use of fossil fuels is contributing to an increase in the carbon dioxide content of the atmosphere
What is mass deforestation causing, in relation to the carbon cycle?
In addition, mass deforestation is reducing the amount of producers available to take carbon dioxide out of the atmosphere by photosynthesis
What is mass deforestation specifically for land causing, in relation to the carbon cycle?
This problem is exacerbated by the fact that in many areas of the world, deforestation is taking place for land rather than for the trees themselves, and as such they are burnt down, releasing yet more carbon dioxide into the atmosphere
What are the 4 basic steps of the carbon cycle?
Carbon is taken out of the atmosphere by photosynthesis
It is passed on to animals and decomposers by feeding
It is returned by respiration; in plants, in animals and in decomposing
microorganisms
In addition, it is returned (in increasing amounts) by combustion of fossil fuels
- Where do water molecules move between?
Water molecules move between various locations – such as rivers, oceans and the atmosphere – by specific processes
- How is water able to move between certain locations?
This is possible because water changes state at a relatively low temperature
- In what form does water enter the atmosphere?
Water enters the atmosphere as water vapour
- In what two processes can water vapour enter the atmosphere?
evaporation
- transpiration
- How does evaporation work?
Energy from the Sun heats the Earth’s surface and water evaporates from oceans, rivers and lakes
- How does transpiration work?
Transpiration from plants releases water vapour into the air
- What does the warmer air of the lower atmosphere do?
The warmer air of the lower atmosphere rises, taking the water vapour with it
- What happens to the warm air as it rises and what does this form?
The moist air cools down as it rises
Water vapour condenses back into liquid water, forming clouds
- How does water return to the earth?
Water returns to Earth in the form of precipitation
- How does precipitation occur?
As the water droplets in the cloud get bigger and heavier, they begin to fall as rain, snow and sleet
This is called precipitation
- What is nitrogen used for?
Nitrogen as an element is required to make proteins
- Why is N2 gas not very useful?
Neither plants nor animals can absorb it from the air
- Why can N2 gas not be absorbed from the air?
N2 gas is very stable and the bonds holding the nitrogen atoms together would need massive amounts of energy to break (the two nitrogen atoms in a nitrogen molecule are held together by a triple covalent bond)
- In what two ways can N2 be taken out of the air and converted into something which can be used?
nitrogen fixing bacteria
- lightning can ‘fix’ it
- How can nitrogen fixing bacteria convert N2 to a useable form?
take N2 gas and change it into nitrates in the soil
- How can lightning convert N2 to a useable form?
splitting the bond between the two atoms and turning them into nitrous oxides like N2O and NO2 that dissolve in rainwater and ‘leach’ into the soil
- Where can nitrogen fixing bacteria be found?
found ‘free living’ in soil and also in the root nodules of certain plants (peas, beans, clover – we call them leguminous plants)
- In what form do plants absorb N?
Plants absorb the nitrates they find in the soil and use the nitrogen in them to make proteins
- How do animals absorb N?
Animals eat the plants (or other animals) and get the nitrogen they need from the proteins in the plant or animal
- How is N returned back to the soil from animals?
Waste (urine and faeces) from animals sends nitrogen back into the soil as ammonium compounds (the urea in urine contains nitrogen)
- What happens to the N present in animals and plants when they die?
When the animals and plants die, they decay and all the proteins inside them are broken down into ammonium compounds and put back into the soil by decomposers
- Why are ammonium compounds not useful and how is this problem fixed?
The plants can’t absorb ammonium compounds though, so a second type of soil bacteria, nitrifying bacteria, are used to convert the ammonium compounds
- What do nitrifying bacteria do? how is the useful?
nitrifying bacteria, convert the ammonium compounds to nitrites and then to nitrates, which can then be absorbed by plants – and so the cycle goes on
- What third type of bacteria also uses N?
type of (anaerobic) bacteria called denitrifying bacteria
- Where are denitrifying bacteria found?
found in poorly aerated soil (ie not much oxygen)
- What do denitrifying do?
These bacteria take the nitrates out of the soil and convert them back into N2 gas
- How can farmers help decrease the number of denitrifying bacteria?
Farmers can help reduce the amount of these unhelpful bacteria by ploughing and turning over soil
Population definition
A population is defined as a group of organisms of one species, living in the same area at the same time
Community definition
A community is defined as all of the populations of different species in an ecosystem
Ecosystem definition?
An ecosystem is defined as a unit containing the community of organisms and their environment, interacting together (eg a decomposing log, a lake)
What do living organisms compete with each other for?
All living organisms compete with each other for food, water and living space
What type of organisms increase their populations the fastest?
Those which are the best adapted to their environments generally increase their populations at the expense of those less well adapted
What 3 factors affect population growth?
Food supply
Predation
Disease
In what way has human population been growing for the last 150 years?
Human population growth globally has been increasing exponentially for the last 150 years
What are reasons for the exponential growth of the human population?
Improved technology leading to an abundance of food = rapid increase in birth rate
Improved medicine, hygiene and health care = decrease in death rate
What is the name of a population growth graph which looks like an s?
The shape of this curve ( a little like an ‘S’), gives it its name – a sigmoid growth curve
What 4 phases does a sigmoid graph have?
lag phase
log
phase
stationary phase
death phase
What is the lag phase on a s graph?
organisms are adapting to the environment before they are able to reproduce; in addition, at this stage there are very few organisms and so reproduction is not producing larger numbers of offspring
What is the log phase on a s graph?
(aka exponential phase) – food supply is abundant, birth rate is rapid and death rate is low; growth is exponential and only limited by the number of new individuals that can be produced
What is the stationary phase on a s graph?
population levels out due to a factor in the environment, such as a nutrient, becoming limited as it is not being replenished; birth rate and death rate are equal and will remain so until either the nutrient is replenished or becomes severely limited
What is the death phase on a s graph?
population decreases as death rate is now greater than birth rate; this is usually because food supply is short or metabolic wastes produced by the population have built up to toxic levels
Are organisms in natural environment likely to show a population growth like a sigmoid growth curve? Why?
NO
- because they’re affected by many other factors
What factors affect can organisms in a natural environment? 5
changing temperature or light
predators
disease
immigration (individuals moving into the area)
emigration (individuals moving out of the area)
Define food chain
The transfer of energy from one organism to the next, beginning with a producer
Define trophic level
The position of an organism in a food chain, food web, pyramid of numbers or pyramid of biomass
Why is the transfer of energy from one trophic level to the next inefficient?
Because of egestion, excretion, respiration and production of inedible bones and shells
Define food web
A network of interconnected food chains
Define Producer
An organism that makes its organic nutrients usually from energy from sunlight through photosynthesis
Define Consumer
An organism that gets its energy by feeding on other organisms
Define Herbivores
An animal that gets its energy by eating plants
Define Carnivores
An animal that gets its energy by eating other animals
Define Decomposer
An organism that gets its energy from dead or waste organic material
Why is the pyramid of biomass better than the pyramid of numbers?
Pyramids of biomass take into account the size of organisms
Less misinterpreted
Range of numbers may be enormous
What is the importance of the water cycle?
Living organisms require water- provides organisms with a constant supply of water
How is nitrogen fixed?
By lightning and bacteria -root nodules of certain plants (peas, beans, clover – leguminous plants) take N2 gas and change it into nitrates in the soil
What produces ammonium ions?
Decomposers break dead matter down into ammonium ions
What converts ammonia into nitrites and nitrates
Nitrifying bacteria
What absorbs nitrate ions?
Plants
What release nitrogen back into the atmosphere?
Denitrifying bacteria
What is deamination?
Removal of the amine group in an amino acid
What is nitrogen fixation?
is when N2 and H2 combine to form ammonium ions then nitrate if oxygen is present
What are legumes used for?
To avoid using so much nitrogen- containing fertiliser so therefore it is less expensive
What is nitrification?
When ammonium ions are produced by the decomposition of amino acids and are oxidised first to nitrite then to nitrate
What is denitrifying?
When nitrate is converted to nitrogen gas
Define population
A group of organisms of one species living in the same area at the same time
Define Ecosystem
A unit containing the community of organisms and their environment interacting together
Define community
All of the populations of different species in an ecosystem
What is population growth controlled by?
Food supply
Predation and disease
Why has the population size increased significantly?
Because of improved technology leading to an abundance of food and improved medication and health care
Describe the sigmoid growth curve?
Log phase
Exponential phase
stationary phase
death phase
Community definition
A community is a group of populations of different species living together in the same place (e.g. A woodland community could contains squirrels, deer, insects, birds e.t.c) different species in a community rely on each other
Habitat definition
A habitat is a place where an organism lives, referring to a general area where many species are found. (It is a physical place)
Ecosystem definition
An ecosystem describes all the species, populations, habitats and communities in an area. It is a self contained, interacting community of organisms and the environment. (Lake ecosystem, woodland ecosystem)
What is the first thing in a food chain
A producer e.g. A plant.
What comes after the producers in a good chain
Primary, secondary, tertiary consumers
What categories do these consumers fall in to
Herbivores, carnivores and omnivores
What are detritivores?
Animals that feed off of waste (maggots, worms, dung beetles e.t.c)
What is biomass?
The mass of material in living organisms
What happens to energy as it passes through a food chain?
It gets used up and less is available at each trophic level
Why is there only about 10% of energy transferred from one trophic level to another
Because energy is passed out of the food chain by being used as heat energy, for life processes (e.g. movement) and faeces and remains are passed to decomposers. Less energy is transferred at each level of the food chain so as a result the biomass gets smaller.
Why is not all the biomass from a plant transferred to animal biomass?
Because cows do not eat all of the plant
Some of the plant biomass eaten is excreted by the animal and not turned into animal biomass
Some of the plant biomass eaten is used as energy for metabolic reactions such as respiration or producing heat so is not converted to animal biomass
Not all the plant biomass eaten can be digested (cellulose)
Water cycle
Ground water goes into rivers and streams which makes wet surfaces and bodies of water. This water then evaporates giving water vapour in the air. The water vapour then undergoes condensation to make cloud which turns into ground water again by precipitation. The ground water is turned into water vapour in the air also by being taken up by plants and then transpiration occurs giving water vapour in the air.
Carbon cycle
CO2 in the air is turned into organic material in plants by photosynthesis. This organic material in plants turns into fossil fuels, organic material in animals and dead organic waste(also produced by the organic material in animals. The organic material in plants and animals also puts CO2 back into the air by respiration. Fossil fuels puts CO2 back into the air by combustion. The dead organic waste of plants and animals is turned into organic materials in decomposers by decomposition, the decomposers then put CO2 back into the air by respiration.
What are the three ways that nitrogen in the air is converted into plant proteins.
Nitrogen in the air is turned into nitrates taken up by plants via:
nitrogen fixing bacteria (in soil and root nodules of legumes)
electrical storms
haber process (nitrogen in air converted to ammonia in fertilisers which is turned into nitrates via nitrifying bacteria)
How can excreta and dead protein materials from both animals and plants be turned back into nitrates for plants or back into nitrogen in the air?
Excreta and dead animal proteins is decomposed by decomposers which produces ammonia.
The ammonia is turned into nitrites by nitrifying bacteria and then into nitrates by nitrifying bacteria which is then taken up by plants. OR
The ammonia is turned into nitrogen in the air by denitrifying bacteria.
What are the greenhouse gases?
Water vapour, CO2, nitrous oxide, methane and CFC’s
What creates sulphur dioxide and acid rain?
Sulphur dioxide is produced by the burning of fossil fuels. The sulphur dioxide turns into sulphuric acid by dissolving in the water droplets in clouds, it then falls as acid rain
What are the effects of acid rain
low ph in lakes which kills fish as they get mucus on their gills which leads to bad gas exchange and death
dissolves marble structures as the calcium carbonate is dissolved
low ph in soil kills plants as roots can’t take in mineral ions.
What are control measures for sulphur dioxide pollution
dryer absorber spray which absorbs so2
- filter in chimneys that absorbs the so2 preventing it from getting into the clouds and causing acid rain
What are the sources of carbon monoxide
It is produced by the incomplete combustion of carbon and fuels
Sources: furnaces or boilers, gas stoves and ovens, fire places, motor vehicles, power generators, tobacco smoke
What are the effects of carbon monoxide?
“Silent killer” poisonous gas, dangerous because it is odourless and colourless. Causes: headaches, dizziness, vomiting, nausea and death.
It replaces the oxygen in haemoglobin creating a lack of o2
Control measures
not leaving motors running
do not use motos or generators in small spaces
install a carbon monoxide detector
don’t heat bourse with ovens
don’t burn anything in unvented stoves or fireplaces.
Describe the greenhouse effect
It keeps the earth warm as greenhouse gases cause sun rays to bounce back onto the earth after being reflected but some rays escape.
How does an increase in greenhouse gases lead to global warming?
Too many greenhouse gases cause more rays to bounce back onto the earth and makes it harder for the infrared radiation to get back into space. Because more heat is reflected back onto the earth the earth warms up. This is global warming.
How do human activities produce carbon dioxide
produced by the combustion of fossil fuels and internal combustion of engines and deforestation reduces the uptake of CO2
How do human activities produce methane
Meghan is produced by bacteria in the gut of ruminants (cows) and by decomposing bacteria in water logged conditions such as swamps and rice fields.
Produced by the decay of waster materials as anaerobic decay produces methane sometimes.
How to human activities produce CFC’s?
Chlorofluorocarbons are used as aerosol propellant and refrigerator coolant.
How do human activities produce nitrous oxide?
Rocket motors and car racing motors
Nitrogen fertilisers (nitrates in soil are converted to nitrous oxide (an nitrogen gas) by denitrifying bacteria)
What are the consequences of global warming?
rising sea levels (expansion of water due to increased temps) =higher ricks of flooding
melting ice caps and glaciers =impact on wildlife, rising sea levels, flood risk
changes in weather patterns =more extreme weather (temps, rainfall, drought, wind, severe storms)
changes in plant and animal distribution
higher yield (more light, different plants can grow)
less ice in glaciers and less snowfall =reduces meltwater supplies to dependent areas, knock on effect to food supply
ocean expansion. Ice reflects back IR, less I e, water is darker and absorbs more IR, increase temps so water expands causing rising sea levels. Ice helps cool the planet so planet warms up
Population definition
A population is a group of individuals of the same species living in the same place at a certain time.
What happens if raw sewage is released into water?
The water will become polluted. Bacteria and fungi will decay the matter and use up oxygen dissolved in the water when they respire. This causes biological oxygen demand (BOD) so other animals and fish will die due to lack of oxygen.
Eutrophication definition
The process by which a lake or river becomes enriched with dissolved nutrients. This results in the growth of aquatic plants which can ultimately result in a decrease of dissolved oxygen (increased BOD) and the death of living organisms
Describe the process of eutrophication
Excess nutrients make algae grow faster. This algae then dies as well as plants shaded by the algae. The dead matter is decomposed by microbes. The microbes respire and use up oxygen causing BOD so aquatic animals suffocate and die.
How can eutrophication be prevented
Treat sewage before it enters rivers
Prevent farmyard drainage entering rivers and ponds
Control the use of fertilisers
Bubble air in badly polluted ponds.
What are the consequences of deforestation (4 things)
leaching
soil erosion
disturbance of water cycle
change in balance of atmospheric oxygen and carbon dioxide
What is leaching
Where mineral nutrients contained in top layers of soil are washed deeper in the soil so overtime the top soil becomes infertile.
What is soil erosion
Where the top soil is washed away because it is exposed directly to wind and rain. This removal will lead to a loss of soil structure which causes a loss in fertility
How does deforestation lead to a disturbance of the water cycle
Most of the rainfall is absorbed by the tree foliage or root system so when the trees are gone the soil can not absorb all of the water which leads to floods and landslides. On a more global scale loss of forests reduces transpiration which leads to a dryer atmosphere and less rainfall globally.
How does is change the balance of atmospheric oxygen and carbon dioxide
Less CO2 is absorbed for photosynthesis and more is released by the burning of trees. This leads to an enhanced greenhouse effect.
Less oxygen is produced which in the long term could cause problems for respiration
The Sun is the
principal source of energy input to biological systems.
The flow of energy through
living organisms, including light energy from the Sun and
chemical energy in organisms, is eventual transfer to the environment.
A food web
is a network of interconnected food chains.
A producer
is an organism that makes its own organic nutrients, usually using energy from sunlight, through photosynthesis.
A consumer
an organism that gets its energy by feeding on other organisms
Consumers may be classed as
primary, secondary, tertiary and quaternary
according to their position in a food chain.
A herbivore
is an animal that gets its energy by eating plants
A carnivore
is an animal that gets its energy by eating other animals
A decomposer
is an organism that gets its energy from dead or waste organic material.
Advantages of using a pyramid of biomass rather than a pyramid of numbers to
represent a food chain:
in a pyramid of numbers one large individual is shown in the same way as
one very tiny individual ;
biomass indicates how much food there is, available / left ;
biomass is an indicator of the energy available ;
pyramid of biomass is pyramid shaped whereas a pyramid of numbers is not
always
A trophic level
the position of an organism in a food chain, food web or ecological pyramid.
Advantages of using a pyramid of energy rather than pyramids of numbers or biomass to represent a food chain:
it shows how much energy is available
it shows how much energy is passed through per meter square
other pyramids are not very informative, because we cannot be sure that one
gram of biomass for one species contains the same quantity of energy as one
gram of biomass of a different species.
Transfer of energy from one trophic level to another is often not efficient because
energy is lost between tropic levels. Energy is lost in respiration, movement,
muscles contraction, heat. Energy is lost in faeces, urine. Not all animal or plant is
digestible. Only 10% of the energy is transferred. As we move up the food chain
lesser and lesser energy is available to support a population. Therefore a food chain
is not longer than 5 tropic levels.
nitrogen fixation occurs by
lightning or by bacteria in root nodules, they convert
nitrogen from air into ammonia.
ammonia is converted to
nitrate ions in the process of nitrification, by nitrifying
bacteria.
the plant absorbs nitrate ions from
the soil.
plant produce amino acids and protein from
nitrate ions
animals feed and digest
protein.
deamination of protein occurs in
animals and they excrete it as urea.
bacteria decompose plant and animal proteins into
ammonium ions.
ammonium ions are converted to
nitrogen in the process of denitrification, by
denitrifying bacteria.
A population
a group of organisms of one species, living in the same area, at the same time
A community
all of the populations of different species in an ecosystem.
An ecosystem
as a unit containing the community of organisms and their
environment, interacting together
Factors affecting the rate of population growth for a population of an organism
food supply
competition
predation
disease
Food chain
it shows the transfer of energy from one organism to the next, starting with a producer
Trophic level
the position of an organism in a food chain, food web, pyramid of number or biomass
Food web-
The network of interconnected food chains
Producer
organism that makes their own food, usually using energy from sunlight, through photosynthesis
Consumer
organism that gets its energy by feeing on other organisms
Herbivore
organism that gets its energy by feeing on plants
Carnivore
organism that gets its energy by feeding on other animals
Omnivore
organisms that gets its energy by feeing on both animals and plants
Decomposers
organisms that gets its energy by breaking down dead or organic waste material of plants and animals
Population
Group of organism of the same species living in the same area at the same time
Community
all the population of different species in an ecosystem
what do food chains depict in the environment
the direction of energy flow and it is unidirectional
higher the trophic level
number decreases
many food chains =
food web
order of trophic level
producer, primary consumer, secndary consumer, tertiary consumer, top consumer
pyramid of energy
always upright
each trophic level uses 90% of energy in which most of the energy is lost in the form of heat energy by ration or convection
why in a food chain trophic level ends at 4 or 5
no energy so no consumers
energy lost through
radiation or convection
carbon cycle
photosynthesis, respiration, combustion and fossilization
water cycle
evaporation, condensation and precipation
transpiration happens on
leaves
% of the nitrogen in the world
78%
in rainforests nitrogen %
60-65% ( lower % of nitrogen)
in desert nitrogen %
80-85% ( higher % of nitrogen)
why do we need a nitrogen cycle?
inorganic elemnt that life depends on( needed to make amino acids)
the nitrogen cycle is essential for
1) biological fixing
2) chemical fixation
sources of nitrogen
1) lightning (N2+H2O)
2) artificial fertilizers that we use
3) excretion of animals
4) decomposition of dead animals
biological fixing
1) nitrogen-fixing bacteria
nitrification
when any nitrogenous product becomes nitrate with the help of nitrifying bacteria)
denitrifying bacteria is needed for
denitrification
Ecosystem
Unit containing the community of organisms and their environment interacting together ( decomposing log, lake)
Genetic engineering-
changing the genetic material of an organism by removing, changing or inserting individual genes
Sustainable resources
Resources which is produced as rapidly as it is removed from the environment so it doesn’t not run out
Sustainable development
development proving the needs of an increasing population without harming the environment
2 types of cells
prokaryotic and eukaryotic
prokaryotic cells don’t have
a true nucleus
eukaryotic cells have a
true nucleus
restricted endo nucleus enzyme is AKA
restriction enzyme
restricted endo nucleus enzyme is the exact
length of DNA that produces the enzyme insulin, is used to cut a part of the plasmid and replace it with a gene from DNA of the exact same size
why are bacteria used?
because they have plasmind( prokaryotic)
plasmid does not produce
insulin
sticky ends
2 ends of a gene after being cut
DNA ligase works like
glue used to connect human gene
endo nucleus means
it works inside a nucleus
recombinent
new combination
recombinant plasmid will be put back into the
bacteria
bacteria reproduce more quickly and create
insulin
Sterile air
needed to avoid competition with other micro-organisms
prevent contamination of the product
nutrients
for growth and reproduction of microorganisms used in the fermenter
temperature and PH monitor
to read temperature and PH for maintaining optimum values
temperature and PH monitor
to read temperature and PH for maintaining optimum values
sample tube
to check quality and concentration of the product
cooling jacket
to maintain constant temperature in the fermenter
stirrer
it uniformly distributes microorganisms in the solution
allows maximum collision of enzymes and substrates
maintains a constant temperature throughout the solution
prevents the clogging of micro organisms in one area
pressure release valve
maintains the pressure
uses of bacteria in biotechnology and genetic engineering
bacteria are useful in biotechnology and genetic engineering because they can be grown and manipulated ed without raising any ethical concerns. the rate of reproduction is very fast and does not take much time. they have a genetic code that is the same as all other organisms, so genes from other animals or plants can be successfully transferred into bacterial DNA and use their ability to make complex molecules
biotechnology
application of biological organisms, systems, or processes to manufacturing service and industries
metabolism
any chemicAL REACTION THAT TAKES PLACE INSIDE A LIVING CELL
2 types of metabolism
1) anabolism
2) catabolism
anabolism
simple molecules combine to form complex molecules
catabolism
complex molecules combine to form simple molecules
aerobic respiration takes place in
mitochondria
the end product of bacteria
CO2 and methane
end products of fungi
CO2 and ethane
bacterial DNA is in the form of
a circular strand and also small circular pieces called plasmids.
scientists have developed
techniques to cut open these plasmids and insert sections of DNA from other organisms into them
scientists have developed
ethanol formation also called alcoholic fermentation, is a biological process that converts such as glucose, fructose, and sucrose into cellular energy, producing ethanol and carbon dioxides as by-products, because yeasts perform this conversion in the absence of oxygen, alcoholic fermentation is considered an anaerobic process
biodiesel
non-toxic and biodegradable and is produced by combining alcohol with vegetable oil, animal fat, or recycled cooking grease.
the role of anaerobic respiration in yeast during bread making
yeast is the microorganism used in bread making. flour water, salt, oil, and yeast are mixed to make a dough. yeast respires anaerobically producing carbon dioxide as the end product. carbon dioxide produced by the yeast causes the dough to rise
use of pectinase in fruit juice production
pectinase is used to separate the juices from fruit such as apples. the enzymes can be extracted from fungi such as Aspergillus niger. they work by breaking down pectin, the jelly-like substance that sticks to plant cell walls to each other. the enzymes can also be used to make the fruit juice clear and transparent
define enzyme
protein which acts as a biological catalyst to speed up any chemical reaction without changing itself and is produced by a living cell
population
number of organisms of the same species living in the same area at the at the same time
lag phase
the population slightly decreases as the organisms are adapting to their new environment
the organisms are yet to mature for reproduction
log phase
plenty of nutrients and no competition
plenty of space and no competition
the absence of predators
no diseases
birthrate is greater than the death rate
stationary phase
competition for nutrients
competition for space
accumulation of waste products
birth rate = death rate
death phase
lack of nutrients
lack of space
excess of toxic waste products
birth rate is less than death rate
The Sun is the
principal source of energy input to biological systems.
The flow of energy through
living organisms, including light energy from the Sun and
chemical energy in organisms, is eventual transfer to the environment.
A food web
is a network of interconnected food chains.
A producer
is an organism that makes its own organic nutrients, usually using energy from sunlight, through photosynthesis.
A consumer
an organism that gets its energy by feeding on other organisms
Consumers may be classed as
primary, secondary, tertiary and quaternary
according to their position in a food chain.
A herbivore
is an animal that gets its energy by eating plants
A carnivore
is an animal that gets its energy by eating other animals
A decomposer
is an organism that gets its energy from dead or waste organic material.
Advantages of using a pyramid of biomass rather than a pyramid of numbers to
represent a food chain:
in a pyramid of numbers one large individual is shown in the same way as
one very tiny individual ;
biomass indicates how much food there is, available / left ;
biomass is an indicator of the energy available ;
pyramid of biomass is pyramid shaped whereas a pyramid of numbers is not
always
A trophic level
the position of an organism in a food chain, food web or ecological pyramid.
Advantages of using a pyramid of energy rather than pyramids of numbers or biomass to represent a food chain:
it shows how much energy is available
it shows how much energy is passed through per meter square
other pyramids are not very informative, because we cannot be sure that one
gram of biomass for one species contains the same quantity of energy as one
gram of biomass of a different species.
Transfer of energy from one trophic level to another is often not efficient because
energy is lost between tropic levels. Energy is lost in respiration, movement,
muscles contraction, heat. Energy is lost in faeces, urine. Not all animal or plant is
digestible. Only 10% of the energy is transferred. As we move up the food chain
lesser and lesser energy is available to support a population. Therefore a food chain
is not longer than 5 tropic levels.
nitrogen fixation occurs by
lightning or by bacteria in root nodules, they convert
nitrogen from air into ammonia.
ammonia is converted to
nitrate ions in the process of nitrification, by nitrifying
bacteria.
the plant absorbs nitrate ions from
the soil.
plant produce amino acids and protein from
nitrate ions
animals feed and digest
protein.
deamination of protein occurs in
animals and they excrete it as urea.
bacteria decompose plant and animal proteins into
ammonium ions.
ammonium ions are converted to
nitrogen in the process of denitrification, by
denitrifying bacteria.
A population
a group of organisms of one species, living in the same area, at the same time
A community
all of the populations of different species in an ecosystem.
An ecosystem
as a unit containing the community of organisms and their
environment, interacting together
Factors affecting the rate of population growth for a population of an organism
food supply
competition
predation
disease
