GCSE Biology- B7 Ecology

What is a habitat?

where the organisms live

What is an individual?

a single member of a species

What is the population?

all the individuals of a species living in a habitat at the same times

What is a community

lots of different population living in the area

What is an ecosystem?

the interaction of a community of living organisms with the non-living parts of the environment

What is competition?

organisms competing against each other for resources in-order to survive

What do animals compete for?

food, territory, water, mates

What do plants compete for?

water, light, space, mineral ions

What is intraspecific competition?

competing within the same species

What is interspecific competition?

competing outside of the species, between others

What is interdependence?

different species relying on each other for their survival

Examples of interdependence

birds using trees to make nests, lions using long grass for camouflage, flowering plants using bees to pollinate, animals or plants may carry plant seeds away from the parent plant to avoid competition

What is a stable community?

all the environmental factors and species are in balance, so that population sizes remain fairly constant

What are biotic factors?

living factors

What are abiotic factors?

non-living or physical factors

What are abiotic factors affecting communities?

light intensity, CO2 concentration, temperature, moisture level, soil pH, mineral content, wind direction/intensity

What are biotic factors affecting communities?

predation, competition, availability of food, diseases,

What is adaptation?

a feature or characteristic that helps an organism to survive

What are behavioural adaptations?

how an organism behaves

What are examples of behavioural adaptations?

migration, hibernation

What are structural adaptations?

the features of an organism's body features

What are examples of structural adaptations?

webbed feet, SA:V ratio, thick bark

What are functional adaptations?

processes inside an organism body

What are examples of functional adaptations?

poison, production of toxins

What is a producer?

organism that produces its own food, usually a green plant

What is a consumer?

organism which eats its food

What is a preadator?

organism that kills and eats something

What is the primary consumer?

The 1st organism in food chain that consumes others

What do the arrows in a food chain represent?

transfer of energy/direction of energy flow

What is the secondary consumer?

the organism that consumes the primary consumer, which is generally a carnivore

What is the tertiary consumer?

The organism that consumes the secondary consumer

What are the producers?

photosynthetic organisms that are the producers of biomass for life on earth and makes glucose via photosynthesis for respiration and energy

What is the apex predator?

the top of the food chain with no natural predators above it.

What is the trophic level?

the feeding level in a food chain

What are decomposers?

organisms that can break down plants, animals matter and small soluble food molecules then diffuse into them, (can be at all trophic levels)

What are food webs?

a diagram showing all the eating relationships in a habitat

What is biomass?

mass of living tissues (or recently dead tissues) that have not yet been decomposed) that a plant or animal is made up of

What are pyramids of biomass?

shows biomass of each organism at trophic level

What are pyramids of numbers

Shows the number of individuals at each trophic level

What are problems with pyramids?

organisms may belong to more than one trophic level, problems with measuring biomass/involves drying out and weighing the mass of organisms

What is the efficiency of energy transfer?

rarely more than 4 levels, fewer trophic levels= more efficient food chain

What is the equation for energy efficiency?

Energy efficiency= energy connected to biomass/total energy taken in

What is the equation for the biomass transfer efficiency??

(biomass in higher trophic level/biomass in lower trophic level) x 100

What does qualitative mean?

rough idea/description

What does quantitative mean?

specific measurements

What is sampling?

counting the number of organisms in a small area to calculate the total

What is random sampling?

carried out when the study area is fairly uniform , very large and there is limited time available. Large number of samples/records taken

What are the advantages of using random sampling

increase the validity of results due to random

What is used in random sampling?

uses random number generator to decide coordinates, uses quadrats on a grid used when habitat is uniform

What is the method for random sampling (RP)?

Mark area studying, randomly generate 10 coordinates, place a 10x10m grid by using two rulers on the surface, place quadrat in the centre of coordinates chosen, count the number of buttercups and record results in chosen quadrat, repeat with the other 9 coordinates, find the mean from the results

What is systematic sampling?

chosen specific places to put quadrats- usually along a transect line, quadrats placed in straight line, used when there is a change in habitat

What is the equation for the estimated population size?

Estimated population sizes = (total area/area of quadrat) x mean specimen counted

What is the percentage cover?

the approximate % of the quadant are, in which an individual species is found and recorded

What is systematic sampling with a quadrat?

a grid is created and placed over a map of the area to be samples, the map is systematically sampled to avoid bias

What is the transect line?

tape measure which gives us a straight line which we can sample

What is the method for systematic sampling (RP)

lay out tape measure, choose systematic intervals place quadrats at chosen intervals, record intervals, record results count number of species at each location, polt graph of results

What is biodiversity?

the variety of living organisms within an ecosystem

What are the advantages of high biodiversity?

stable ecosystems, different species depending on each other for food and shelter, maintains physical enviroments

What are ecosystem services?

any positive benefit that wildlife or ecosystems provide to people. Benefits could be big or small, direct or indirect.

How does human activity reduce biodiversity?

humans rely on us maintaining a good level of biodiversity many human activities are reducing biodiversity and only recently have some measures been put in place

What is the impact of exponential population growth?

competition for space, for people to live and for enough food

What are examples of species hunted to extinction?

passenger pigeon- wild population from billions to zero in 50 years due to hunting for food, dodo bird- eaten by sailors, thylacine (tasmanian tiger)- persecuted to protect sheep

How does human activity also affect the earth's biodiversity?

deforestation and habitat loss, invasive species, pollution of water removal of keystone species (species with disproportionally large impact on the environment relative to its abundance, climate change, smaller gene pool

What is the impact of deforestation and habitat loss on biodiversity?

reduces biodiversity both by getting rid of habitats and also by reducing the genetic diversity of population

What is the impact of invasive species on biodiversity?

species without a natural predator and manage to outcompete every other animal in the environment, causing huge population loss

What is the impact of pollution of water on biodiversity?

effects biodiversity of sea negatively and through the formation of acid rain via air pollution

What is the impact of removal of keystone species on biodiversity?

other species may increase drastically in number, potentially outcompeting and displacing other species

What is the impact of climate change on biodiversity?

causes massive amounts of habitat loss, and therefore a loss in biodiversity

What is the impact of a smaller gene pool on biodiversity?

complete removal of a dominant allele from inbreeding- causes smaller buffer and less adaptations, making it less likely to survive

Why is genetic biodiversity important?

species were susceptible to change in environment if low genetic diversity, whole population could be wiped out by disease or event

How is biodiversity maintained through breeding programmes?

increase in numbers of endangered species through captive or artificial breeding programmes in zoos. Maintains biodiversity by introducing more of an endangered species.

What are examples of biodiversity maintained through breeding programmes?

Giant pandas

How is protecting and regenerating habitats important to biodiversity?

protects and re-establishes habitats endangered by deforestation and climate change which were once home to many different living organisms.

What is an example of protecting and regenerating habitats?

coral reefs and mangroves

How does wildlife reserves protect biodiversity?

protected area, restricting urban development, industrial development and farming. It controls grazing poaching an restricts human access, feeds animals (ensuring they reach reproductive age) and remove invasive species.

How does marine conservation zones help biodiversity?

creates area of refuge so populations can replenish via strict laws on fishing, recreational use and pollution

What is an example of a marine conservation zone?

Lundy island

How does the reintroduction of field margins and hedgerows?

trees are cut part way through and laid sideways to form a hedge and provide safe habitat, food sources and corridors for organisms to travel along

What is monoculture?

a single crop over an extended area- supports low level of biovidersity

How does reducing deforestation and CO2 emissions help biodiversity?

planting 48 million trees until 2025 (only meeting 1/3 of target per year), reducing CO2 emissions would help slow the rate of global warming-protecting vulnerable species and habitats

How does recycling resources help biodiversity?

preventing pollution by stopping waste being placed in landfills. Affects biodiversity, as more waste= more landfills- more space need= less diversity

What are the conflicting pressures on biodiversity?

cost- very expensive, although has farming subsidies- 3 billion per year spent by UK government protecting biodiversity, effect on local economy- affects unemployment and housing, maintenance of food security- shortage of food, pests, predators continuously killed.

What is decomposition (decay)?

process by which waste products and dead organisms are broken down and the materials they contain (carbon, mineral ions) are returned to the environment.

What organisms carry out decay?

carried out by decomposers (microorganisms)- mainly bacteria and fungi

What is the water cycle?

provides fresh water for plants and animals on land before draining into seas, water is continuously evaporated and precipitated.

Where does the evaporated water come from in the water cycle?

lakes, oceans and streams

What happens in condensation stage of water cycle?

hot air is less dense than cold air, therefore it rises. As it rises, it cools to form clouds by condensation

What is the carbon cycle?

returns carbon from organisms to the atmosphere as CO2. Plants use CO2 in photosynthesis. Microorganisms return CO2 to the atmosphere as CO2 and mineral ions to the soil by decomposition.

Where does the CO2 in the atmosphere come from?

plant respiration, combustion, animal respiration and mineral carbon from soil

What are organisms involved in decay?

slugs, bacteria, fungi, flies, snails, worms, ants, other microorganisms

What are detritivores?

animals which feed on dead organic materials

What do detritivores do?

breaks down particles into similar smaller bits, so there is a large surface area fr bacteria and fungi to colonise and feed on.

What are the three factors for rate of decay?

temperature, moisture and oxygen

How does temperature impact the rate of decay?

rate of decay increases if higher temperature, if temperature is too high, enzymes denature and decay stops

How does moisture impact the rate of decay?

more decay if more moisture, needed for transport and reactions inside decomposers. Make sit easier to digest organic matter

How does oxygen impact rate of decay?

needed for respiration, more O2 faster decay

What is compost?

the process of decay to make compost- a natural fertiliser

What is anaerobic decay?

if insufficient O2 is present, then anaerobic decay will occur, this produces Methane gas.

How do biogas generators use anaerobic decay?

biogas generators can be used to anaerobicly digest waste, biological material and produce methane, which could be used as a fuel in a gas form.

How does a biogas generator work?

dung, farm waste and garden waste enter from the top, methane gas rises and is released at the top, slurry- used as a fertiliser, is exited from the bottom.