Science - Biology - Ecology - B7a Flashcards
what is a population ?
all the organisms of one species living in a habitat
what is a habitat ?
the place where an organism lives
what is a community ?
the population of different species living in a habitat
what are abiotic factors ?
non - living factors of the environment
what are biotic factors ?
living factors of the environment
what does abiotic mean ?
non - living
what does biotic mean ?
living
give an example of an abiotic factor of the environment
temperature
give an example of a biotic factor of the environment
food
what is an ecosystem ?
the interaction of a community of living (biotic) organisms with non - living (abiotic) parts of their environment
what is competition ?
organisms competing with other species for the same resources / roles in an ecosystem
give an example of competition
male peacocks displaying their feathers to females during mating season
what is interdependence ?
a community depending on each other for food, shelter, e.t.c
what is a food web ?
a diagram showing what animals eat what in an ecosystem
what can taking one species out of an ecosystem do to it ?
disrupt a whole food-chain which will damage the ecosystem
what is a stable community ?
communities where species and environmental factors are in balance so the population sizes are constant
list abiotic factors in an ecosystem
- moisture levels
- temperature
- light intensity
- carbon dioxide levels
- wind intensity and direction
- oxygen levels
- soil PH and mineral content
list biotic factors in an ecosystem
- new predators arriving
- competition
- new pathogens
- availability of food
give an example of when an abiotic factor can affect the environment
decrease in light, temperature, carbon dioxide levels - less photosynthesis so less plant growth
give an example of when a biotic factor can affect the environment
- new predator can decrease the prey population
give an example of when biotic organisms have outcompeted each other
- red squirrels in the UK being outcompeted by grey squirrels resulting in less red squirrels
what is an adaptation ?
the features of an organism which is adapted to live in an environment
what are the 3 types of adaptation ?
- structural
- behavioral
- functional
what is a structural adaptation ?
an adaptation to do with body structure, e.g shape, colour
what is a behavioral adaptation ?
the way an organism behaves
what is a functional adaptation ?
what goes on inside an organisms body that is related to a process, such as reproduction
give an example of a structural adaptation
- arctic animals, such as an arctic fox having white fur to camouflage against the snow to hide from predators
give an example of a behavioural adaptation
- species such as swallows migrating to warmer climates during winter to avoid the problems of living in cold conditions
give an example of a functional adaptation
desert animals conserving water by producing very little sweat and small amounts of concentrated urine
what is an extremophile ?
an organism/microorganism that’s adapted to live in very extreme conditions
give an example of an extremophile
thermoccus litoralis is a bacterium which live in deep hydrothermal vents, they can survive and reproduce at temperatures between 85-88 degrees celcius
how are weddell seals adapted to live in the cold antarctic conditions and hunts fish in ice covered water, they have whiskers, a streamlined body, and a layer of blubber. How are they adapted to suit their environment ?
- whiskers help them to detect fish in the dark underwater
- layer of blubber insulates them in cold water
- streamlined body helps them reduce resistance in the water so they can swim faster and catch fish
what is a food chain ?
a diagram showing what eats what in an ecosystem
what is a producer ?
organism at the start of the food chain - makes their own food using energy from a primary source such as the sun
what is biomass ?
the mass of a living material
what does a producer do linked to biomass ?
the producer uses some of its glucose to create its biomass
how is energy transferred in an ecosystem ?
organisms eating other organisms
what is a primary consumer ?
the consumer which eats the producer
what is a secondary consumer ?
the consumer which eats the primary consumer
what is a tertiary consumer ?
the consumer which eats the secondary consumer
give an example of a food chain
dandelion - rabbit - fox
what is a predator - prey cycle ?
a cycle showing how the population of one organism affects the population of another organism
give an example of a predator prey cycle
if the number of prey increases, the number of predators will increase
what is a predator ?
an animal that hunts and kills other animals
what is prey ?
an animal that is eaten by other animals
what can environmental changes cause ?
distibution of organisms to change
what does a change in distribution mean ?
a change in where an organism lives
give an example of an environmental change in availability of water ?
distribution of plant and animals change in trophics changes between wet and dry seasons, where there is more or less rainfall
give an example of an availability of water change ?
in africa yearly giant wildebeest migrate moving north then back south as rainfall patterns change
how does change in temperature affect distribution ?
distribution of bird species changes due to change in temperature
how does the change of composition of atmospheric gases affect distribution ?
changes in areas where there is more air pollution
give an example of how atmospheric gases affect distribution ?
species of lichen can’t grow in areas where sulpher dioxide is given out by certain industrial processes
what factors cause these environmental changes ?
-seasonal
- geographic
- human interaction
explain the water cycle
- energy from the sun makes water evaporate from the land, sea turning it into water vapour
- water also evapourates from plants in transpiration
- water vapour rises up, cools and condenses
- this forms clouds
- water falls from clouds as precipitationonto land providing fresh water
how do living things made of materials using the world around them ?
plants turn elemtns such as carbon, oxygen, hyrdorgen, nitrogen from the soil and air and turn them into compounds which make up living organisms
why do materials decay ?
they have been digested by microorganisms
what are the optimum levels for decay ?
in warm, moist, aerobic, conditions as microorgansisms are most active in these
what does decay do ?
puts stuff plants need to grow back into the soil
what happens in a stable community with decay ?
materials taken out of the soil and used by plants are balanced by those put back in
describe the carbon cycle ?
- CO2 in the air
- carbon is used in photosynthesis
- carbon compounds are used in plants through eating, respiration
- products are made from plants and animals which have carbon, e.g clothes
- animals dies and decay where C02 is released
- fossil fuels are burnt releasing carbon in the air
how is carbon taken out of the air ?
in photosynthesis by green plants and algae
how is carbon used in photosyntheisis ?
to make glucose which helps make up the bodies of the plants and algae
how does carbon move through food chains ?
carbon become part of the fats and proteins in animals when green plants and algae is eaten
energy from green plants and algae moves up food chain
what do detritus feeders and microorganisms do when animals die ?
feed on their remains
what do detritus feeders and microorganisms break down ?
waste
how is carbon returned back into the air ?
when organisms respire
when useful plant and animal products such as wood and fossil fuels are burnt
how does temperature affect rate of decay ?
warmer temp makes things decompose quicker as they increase the rate enzymes work at
what happens if temp is too hot in decay ?
enzymes become denatured so it slows down or stops
what happens if temp is too cold in decay ?
slows rate of decomposition
how does oxygen availability affect rate of decay ?
many organisms need oxygen to respire which they need to survive, however some microorganisms involved in anaerobic decay don’t need oxygen
how does water availability affect rate of decay ?
happens faster in moist environments as organisms need water for biological processes
how does the number of decay organisms affect rate of decay ?
more microorganisms, faster decomposition happens
what is compost ?
decomposed organic matter that is used as a natural fertiliser for crops and garden plants
why is compost good ?
it recycles nutrients back into the soil givin farmers lovely soil improving crop growth
what helps make the best compost ?
compost bins
what is the b7 practical ?
investigating decay by observing action of enzyme lipase on sample of milk that has been made alkaline, when lipase breaks the milk down, PH of milk decreases
what does practical 10 investigate ?
how temperature affects rate of decay
what indicator is used in p10 practical ?
phenolphthalein
what happens to the colour of phenolphthalein when ph drops ?
it is pink at PH 10, but goes colourless below Ph 8.3
describe b7 p10 practical ?
- measure 5cm of lipase solution and add to a test tube
- measure 5cm of milk and add to a different test tube
- add 5 drops of phenolphthalein to tube with milk
- measure 7cm of sodium carbonate solution and add it to tube with milk which makes solution alkaline, turning it pink
- put both tubes in water bath at 30 c and leave them to reach temp of water bath
- once tubes reach 30 c use dropping pipette to put 1cm of lipase solution into the milk tube and start a stopwatch
- stir contents of tube, enzyme with start to decompose milk
- as soon as solution loses pink colour, stop stopwatch and record how long it took to colour change
- repeat experiment at a range of different temperatures
- use results to calculate rate of decay
what is biogas ?
mainly made up of methane, can be burnt as a fuel
why are microorganisms used to produce biogas ?
they decay plant and animal waste anaerobically which produces methane gas
what is used to make biogas on large scale ?
sludge
what is biogas made in ?
a simple fermenter called a digester or generator
why are biogas generators kept at a constant temperature ?
to keep microorganisms respiring
what are biogases used for ?
cooking,heating,lighting
what are the 2 types of biogas generators ?
batch generators
continuous generators
what are batch generators ?
make biogases in small batches manually loaded up with waste which is left to digest and by products are cleared away at the end
what is the disadvantage of a batch generator ?
don’t produce biogas at a steady rate
what is a continuous generator ?
makes biogas all the time, waste is continually fed in, and produced at a steady rate, better for large scale biogas projects
what to all biogas generators need to have ?
- an inlet for waster material to be put in
- an outlet for digested material to be removed through
- an outlet so biogas can be piped to where it is needed
what is biodiversity ?
the variety of different species of organsisms on earth or within an ecosystem
why is high biodiversity important ?
it means ecosystems are stable as one species is less likely to have to rely on a singles different species for the resources and physical environment it needs as there’s a higher chance more than one species in an ecosystem can provide this
what human actions are reducing biodiversity ?
global warming
waste production
deforestation
why is human population increasing ?
modern medicine and farming methods means less people are dying
why are humans putting demands on the environment ?
people want a higher standard f living, so we use more raw materials and use more energy for this process
why will we run out of these resources eventually ?
raw materials are being used up faster than they are being replaced
how does sewage and toxic chemicals harm water ?
pollutes lakes rivers, water affecting plants and animals who need them for survival chemicals used on land to help grow crops can be washed into water
how does toxic chemicals harm land ?
buring nuclear waste underground and dumping household waste on landfill sites doesn’t breakdown easily
how does toxic chemicals harm air ?
smoke and acidic gases pollute the air
explain the greenhouse effect
- energy from the sun is absorbed by earth
- earth radiates this energy back out into the atmosphere
- greenhouse gases in atmosphere absorb the energy
- gases re-radiate the energy in all directions including back down to earth
what is the temperature of the earth a balance of ?
the energy it gets from the sun and the energy it radiates back into space
what are greenhouse gases ?
gases in the atmosphere which help keep the energy in
give examples of greenhouse gases
carbon dioxide and methane
what is global warming ?
where the earth is gradually heating up due to the rise in greenhouse gases
summarise the causes and effects of the greenhouse effect
- increasing levels of co2 and methane
- increasing greenhouse effect
- global warming
- other types of climate change
how does global warming affect sea levels ?
as the sea gets warmer it expands causing them to rise
if it keeps rising people in low lying places will flood leading to the loss of habitats
it also makes ice melt causing sea to further rise
how does global warming affect the distribution of organisms ?
as global temps rise some species who live in warm areas may become more widely distributed wheras species who live n cooler conditions live in smaller ranges
how does changes in global warming lead to migration patterns ?
lots of animals migrate in different seasons,
how can global warming lead to less biodiversity ?
animals that can’t adapt to hotter climate they will become extinct , isn’t the right food source, their fur is too hot
why do humans use land ?
quarrying
farming
building
dumping waste
what is deforestation ?
cutting down of forests
why does deforestation happen ?
clear land for farming
grow crops where biofuels can be produced
how can deforestation lead to less biodiversity
species habitats are cut down so they have no where to live
how does deforestation lead to more CO2 in the atmosphere ?
carbon dioxide is released when trees are burnt or cleared microorganisms feeding on dead wood also release carbon dioxide
how does deforestation lead to less carbon dioxide being taken in ?
carbon dioxide removed from atmosphere in photosynthesis is reduced as trees lock up some of the carbon during photosynthesis removing it from the atmosphere for hundereds of years
what are bogs ?
areas of acidic waterlogged land
why do plants that live in boggs not fully decay ?
there isn’t enough oxygen
because of partly rotted plants building up to form peat, what is stored in peat instead of being released to the atmosphere ?
carbon
why is peat boggs being removed ?
for fuel, farmland and compost
why are peat bogs being drained a bad thing ?
when its drained it comes into contact with air and some microorganisms start to decompose it these microorganisms use oxygen and substances found in peat as reactants for respiration this releases carbon dioxide as a product of respiration
what is a breeding programme ?
prevent endangered animals becoming extinct animals are bred in captivity to mkae sure species survive if it dies in the wild
programmes to protect and regenerate rare habitats
protects species that live there, preserves ecosystem and biodiversity
reintroduce hedgerows and field margins
areas of land around edges of fields where wild flower and grass is left to grow - provides a habitat for a wider variety of organisms
regulations about deforestation levels
limits amount of carbon dioxide being released
recycling
reduces waste dumped in landfill sites
why are protection programmes difficult ?
- costly
- unemployment
- conflict with food security , pests killed to protect crops
- development of cities, industrial areas is stopped
what are trophic levels ?
DIFFERENT STAGES OF THE FOOD CHAIN
what is in trophic level 1 ?
producers
give an example of an organism at trophic level 1
algae
whats in trophic level 2 ?
primary consumers, herbivores
give an example of an organism at trophic level 2
arctic hare
what is in trophic level 3 ?
secondary consumers, carnivores
trophic level 3 e.g
arctic fox
what is in trophic level 4 ?
tertiary consumers - apex predators
trophic level 4 e.g
arctic wolf
what are decomposers ?
bacteria and fungi which decompose any dead plant or animal material left in the environment
how do decomposers work ?
they secrete enzymes that break dead stuff down into small and soleuble food molecules
what do pyramids of biomass show ?
the relative mass of each trophic level
what does each bar on a biomass pyramid show ?
relative mass of living material at trophic level - how much all the organisms would weigh if you put them all together
what does the bar along the bottom of the biomass pyramid show ?
trophic level 1 organisms
how is biomass transferred ?
through a food chain in the ecosystem
how is biomass lost ?
- uneaten material,
- waste products
how do you calculate efficiency of biomass transfer ?
biomass transferred to next level/ biomas available at previous level x100
how do you work out biomass that has been lost
subtracting the biomass that is available from that level from the level the biomass was at previously
what factors affect food security ?
- world population increasing
- diets change so certain foods imported from developing countries can increase so rare food becomes rarer
- farmiers deal with new pests/pathogens or changes in environment which can lead to losing crops
- high costs of farming makes it too expensive to maintain food production
- conflicts affect availabilty of food and water
what is overfishing ?
catching too many fish
what is bad about overfishing ?
-waste
- less fish to eat
- oceans food chain is affected
- species of fish may disappear
how can fish stocks be maintained ?
- fishing quotas - limiting amount of fish allowed to catch
- net sizes - reduces number of unwanted fish allows smaller fish to grow and reach breeding age
how can food production be made more efficient ?
- limiting movement of livestock
- keeping them in a temp controlled environment
- less energy moving around
- more energy available for growth
what is the positives of factor farming ?
-cheaper
-easier
what are the disadvantages of factory farming ?
-cruel
-unnatural
- animal welfare
- spread of diseases is easy
- lots of energy to keep temp controlled environment
what is mycoprotein ?
protein from fungi
what is mycoprotein used for ?
high protein meat substitutes
give an e.g of a mycoprotein food ?
quorn (fusarium used)
how is mycoprotein made ?
- fungus respires aerobically
- mixture kept at right temp and PH
- fungal biomass is harvested
- purified and dried
how is human insulin made ?
- plasmid is removed from bacterium
- insulin gene is cut out of human chromosome using restriction enzyme . restriction enzymes recognise specific sequences of dna and cut the dna at these points . cut leaves one dna strand with unpaired bases
- plasmid is cut open with same restriction enzyme leaving same unpaired base
- plasmid and human insulin is mixed together
- ligase is added which joins the sticky ends together to produce recombinant dna
- recombinant dna inserted into bacterium
- modified bacterium is grown in a vat under controlled conditions so you end up with millions of bacteria that produce insulin, treats people with diabetes
what do genetically modified crops help with ?
- increases amount of food a crop provides
- people on developing countries have correct nutrients in their diet
what are concerns with GM crops ?
- you need to tackle poverty first as that is the problem
- dependant on gm crops
- soil wont allow gm crops to survive
what are gm crops ?
geneticall modified crops, help developing coutries have foods with certain charactersitics to solve issues of food shortages and malnurishment
