Unit 1 Flashcards
What is Ecology?
Ecology is the study of the relationships between living organisms, including humans and their physical environment.
Give an example of ecology
A food web in a forest environment
What is an ecosystem?
An ecosystem is a natural until made up of a community of living things and their habitats
What are biotic factors?
Biotic factors are living factors that influence an ecosystem
Give examples of biotic factors
Competition between species, disease, predation, food availability
What are abiotic factors?
Abiotic factors are non-living factors that influence an ecosystem
Give examples of abiotic factors
Temperature, light, soil pH
What is a habitat?
A habitat is the place an organism lives
What is population?
Population is a group of organisms of the same species
What is a community
A community is the sum of all populations of plants, animals and microorganisms living in an ecosystem.
What is an autotroph?
An autotroph is an organism capable of using photosynthesis as a source of energy.
What is a Niche?
A niche is the role an organism plays and resources it uses in an ecosystem.
What does bacteria do when it breaks down dead organic matter?
It releases nutrients back into the environment.
What is interdependence
Interdependence is the interaction of biotic and abiotic factors in an ecosystem.
What is a food chain?
A food chain is a sequence of organisms where each of them feed on a type of organism
What is the main source in a food chain?
The sun
What is a producer?
A producer is a green plant that produce its own food through photosynthesis.
What is a consumer?
A consumer is an organism that consume other organisms in order to gain energy.
What are the three types of consumers?
- Herbivore
- Carnivore
- Omnivore
What do the arrows in a food chain show?
The transfer of energy (energy flow)
What are primary producers?
A primary producer is a green leaf plant that produces its own food.
What is a primary consumer?
A primary consumer is a herbivore that consumes a primary producer.
What is a secondary consumer?
A secondary consumer is typically a carnivore that consumes a primary consumer.
What is a tertiary (apex) consumer
A tertiary consumer is an animal at the top of the food chain that consumes a secondary consumer.
What are detritivores?
Detritivores are organisms that feed on dead plant and animal materials e.g. wood lice
What are decomposers?
Decomposers decompose waste materials but also make nutrients for the ecosystem.
What is ecological productivity?
Ecological productivity is the productivity of an ecosystem which is the rate of production of the amount of organic matter (biomass) accumulated per unit area in unit time.
What are the two main levels of ecological productivity?
- Gross productivity
- Net productivity
What is gross productivity?
Gross productivity is the the measure of all photosynthesis that occurs in an ecosystem.
What is net productivity?
Net productivity is the energy which is left after losses.
How is energy lost?
Through movement, respiration, growth and heat.
What is an endotherm?
An endotherm is an organism which can control is internal body temperature (warm blooded).
Examples include mammals and birds.
Endotherms have a high metabolic rate so they need to eat more frequently to obtain energy.
What is an ectotherm?
An ectotherm is an organism which rely on its external environment for temperature controls instead of generating its own body heat (cold blooded).
Examples include most fish, reptiles and amphibians.
Ectotherm have a lower metabolic rate so feed less regularly
Why do ectotherms tend to have a longer food chain than endotherms?
Ectotherms do not use energy to regulate their own body temperature therefore there is more energy available for the next trophic level.
What is ecological efficiency?
Ecological efficiency is the percentage of biomass (organic matter) produced by one trophic level that is transferred and incorporated into biomass at the next topic level.
What is the equation to calculate ecological efficiency?
Biomass in higher trophic
—————————————- x 100
Biomass in lower trophic
What is density dependent factors?
Density dependent factors are interactions between organisms which reduce the population.
Give examples of density dependent factors.
Density dependent factors include:
- food availability
- food sustainability
- rates of disease
- predation
- competition
What is Density independent factors?
Density independent factors are conditions such as natural disasters that will affect an ecosystem regardless of the number of species.
Give examples of density independent factors.
Density independent factors include:
- increase in rainfall
- lack of rain
- increase in temperature
- decrease in temperature
- forest fires
- earthquakes
- volcanic eruptions
What are 4 ecological events that will affect population density?
- births
- deaths
- emigration
- immigration
What is carrying capacity?
Carrying capacity is the maximum population size of a species that the environment can naturally sustain
What is the name of the two models to show population growth?
The exponential growth model and the logistic growth model.
What are the features of a exponential growth model?
- the graph will typically show a )-shaped curve
- the population grows faster as it grows larger.
- in nature, this growth is not sustainable as a population will eventually exceed resource availability or be affected by density dependent factors
- population increases over time regardless of resources limits or abiotic factors
- an example of this type of growth would be bacteria multiplying in a Petri dish.
What are the features of a logistic geothermal model?
- population grows until it reaches carrying capacity
- a realistic model of a population
- the graph will typically show a s-shaped curve
- the population may overshoot the carrying capacity but this is only temporarily
- this model is more sustainable as it allows the environment to recover.
What are the two main types of competition?
Intra-specific competition
Inter-specific competition
What is inter-specific completion?
Interspecific competition is when two different species compete for the same resources
What is intra-specific competition?
Intra-specific completion is when members of the same species compete for the same resources.
What is symbiosis?
Symbiosis is the relationship between two different species that live closely together.
What are the three types of symbiosis?
Mutualism
Commensalism
Parasitism
What is mutualism?
Mutualism is when two species benefit from living in close proximity to one another
What is commensalism?
Commensalism is a relationship between work species where one benefits and the other is unaffected.
What is parasitism?
Parasitism is when there is an interaction between two species and one benefits whilst the other is harmed.
What is vegetation succession?
Succession is a sequence of changes in the types of species present in a community.
Why do organisms in vegetation succession develop?
The organisms drive change and make the environment more suitable for the next species and die out.
What is primary succession?
Primary succession takes place in an environment that has no vegetation or soil. This can take 1000+ years to take place.
What is secondary succession?
Secondary succession takes place in an environment that was once inhibited and has become barren but still contains soil nutrients.
What is a stage of succession called?
A sere
What is a hydrosere?
Hydrosere is plant succession that takes place in water.
What is a halosere?
Halosere is plant succession that takes place in a salt environment.
What is a psammosere?
Psammosere is plant succession that takes place in a sand environment.
What is plant succession?
Plant succession is a sequence of plant communities inhibiting the same site/areas.
What are the stages of plant succession?
Pioneer species- they break down rock to soil.
Intermediate community- adapts and develops
Climax community
What are the features of primary succession?
- takes more time
- no soil at the start
- would occur after a volcano
- lichens are the first plant