Ecology Flashcards
Define Ecology
study of interactions between living things and their environment
Define Biosphere
part of the earth containing living organisms
Define Ecosystem
group of clearly distinguished organisms that interact with their environment
Define Habitat
place where an organism lives
Define abiotic factors and give 2 examples
non-living factors
eg: soil pH, edaphic factors
Define biotic factors and give 2 examples
living factors
eg: food, competition
What is pyramid of numbers?
represents the number of organisms at each stage in a food chain
What is meant by trophic level?
feeding stage in a food chain
Define edaphic factors
soil factors
What is meant by symbiosis
two organisms from different species that live in close association where at least one of them benefits
What is meant by nitrogen fixation
Conversion of nitrogen gas to nitrates
What is meant by nitrification?
conversion of nitrogen into nitrites and nitrates
What is the function of nitrogen cycle?
so it can be absorbed by organisms
Give 2 factors that influence the size of the human population
- Famine
2. War
If the population of prey declines suggest two possible consequences for the predators
- Less predators
2. Might migrate where there are more prey
What is the principal source of energy for the earths ecosystems?
sun
State one way in which a named organism is adapted to the ecosystem
fox- red fur for camouflage
What is meant by competition?
when organisms actively struggle for a scarce resource and only one of them wins
A relationship between two organisms in which both benefit is called
symbiosis
two sources of the carbon dioxide that are found in the atmosphere
- respiration
2. rocks
pollution
any harmful addition to the environment
Give an example of pollution and describe how this form of pollution can be controlled
animal waste
spread slurry on dry land
Give an example of human activity that results in the pollution of water
too much fertiliser is spread on grassland
fertiliser gets washed in the rivers/lakes
It causes algae to grow
when algae dies the oxygen gets used up and all living things die (eutrophication)
what is meant by conservation
wise management of our existing natural resources in order to maintain biodiversity
Give an example of conservation practise
- Fish quotas
2. large nets
Outline problems associated with waste
- causes disease
- poisonous gasses
- unpleasant smells
Suggest two reasons of minimising waste
- re-use
- recycle
- reduce
- Compost bin
Describe one method of waste management y reference to agriculture
- Slurry
2. spread on dry land or store in leak proof pits
Give one example of the use of micro-organisms in waste management
- decompose
2. break down organic waste
Define quantitative study
record the number of the organisms in an ecosystem
what is meant by fauna?
animals in an ecosystem
Why is only 10% of energy passed onto the next trophic level?
- due to high energy loss
2. 90% of energy is lost due to growth, respiration, excretion and decay
Niche
functional role of an organism in an ecosystem
what is meant by nutrient recycling?
way in which elements (C,N) are exchanged between living and non living components of the ecosystem (reuse of nutrients)
Roles of organisms in the carbon cycle
- Plants- remove CO2 from the environment in photosynthesis and return it in respiration
- Animals- Obtain carbon by eating plants and release carbon in respiration
- Micro-organisms-return carbon to the environment when they decompose dead plants and animals
Causes of global warming
- Increased burning of fossil fuels
2. Deforestation
Effects of global warming
- Sea levels rising
- Weather alters
- Rising temperatures
Carbon and Nitrogen cycle similarities
- Micro-organisms
- Death and decomposition
- Excretion
- Nutrition
Define Eutrophication
- artificial fertilisers are washed into rivers
- algae uses up the nutrients
- algae die and leads to oxygen depletion
Benefits of conservation
- maintain diversity
- Prevent death
- maintain plant species
Difference between intra/inter competition
Intra- takes place between the same species
Intra- involves different species
Difference between contest and scramble competition
Contest- only one win
Scramble- each organism gets some of the resources
Effects of competition
- Controls size of the population
2. Allows natural selection to occur better adapted will survive
Adaptations to survive competition
- Shallow roots to absorb water
- Dandelions have long roots to absorb water
- Blackbird warns competitors
- Yellow petals attract insect pollinators
Give 2 examples of Symbiosis
- Mutualism
2. Parasitism
Give an example of Mutualism
- symbiotic bacteria in the colon supply humans with vitamins
Give an example of Parasitism
- leeches on human skin/lice
Distinguish between endoparasites and ectoparasites
Endo- feed in a living host
Exto- feed on the outside of the host
Name a predator and their adaptation
- Fox
- Behavioural adaptation- fast
- Structural- Long canine teeth and red fur for camouflage
Name a prey and their adaptation
- Rabbit
- Behavioural- narrow underground burrows large predators can’t enter
- Structural- long ears, good hearing to detect predator
Factors that affect population growth
- Famine
- Disease
- Wars
- Contraception
Apparatus to collect plants and animals
- Mammal trap-collect mice
- Pitfall trap-collects insects
- Pooter-collects spiders
Define quantitative and qualitative study
- Quantitative- records the number of each organism
2. Qualitative- records the presence or absence of each organism
Sources of error when conducting an ecological study
- Non-random sampling
- Misidentification
- Miscounting
Describe how you carried out a quantitative study on a named plant
- choose a simple quadrat
- place quadrat at random
- record the presence or absence of the buttercup
- record the results in a table
- calculate the percentage frequency
Describe how you carried out a quantitative survey of a named animal
- set Cryptozoic traps
- collect any snails caught and count them
- mark snails with non-toxic paint
- release traps and collect again 3-4 days later
- count marked and unmarked snails
- calculate the population as shown
Describe how you investigate abiotic factors in a selected ecosystem
- Air temperature –> thermometer
- Soil pH –>pH meter
- Light intensity –> Light meter
Name structural and behavioural adaptation of an earthworm
Structural –> dark brown for camouflage
Behavioural –> stays away from light to avoid predators
Limitations of the pyramid numbers
- do not take the size of the organisms into account (inverted)
- number of organisms are too large to draw (distorted)
example of the pyramid of numbers
- Grass-rabbit-fox
- oak-greenfly-spider-thrush
- dandelions-snails-hedgehogs-fleas
Role of organisms in the nitrogen cycle
- Nitrogen-fixing bacteria- convert nitrogen to nitrates
- Bacteria of decay-nitrogen waste into ammonia
- Nitrifying bacteria- convert ammonia nitrites and nitrates
- Denitrifying bacteria- convert nitrates to nitrogen gas
