Unit 5: Ecology And Evolution Flashcards
Community
A group of populations living and interacting with each other in an area
Habitat
The environment in which species normally live, or the location of a living organism
Population
A group of organisms of the same species who live in the same area at the same time
Ecosystem
A community and it’s abiotic environment
Ecology
The study of relationships between living organisms and between organisms and their environment
Autotroph
An organism that synthesises it’s organic molecules from simple inorganic substances (plants)
Heterotroph
An organism that obtains organic molecules from other organisms (owls)
Consumer
An organism that ingests organic matter that is living or recently killed (wolves)
Detrivore
An organism that ingests non-living organic matter (earthworms)
Saprotroph
An organism that lives on or in non-living organic matter, secreting digestive enzymes into it and absorbing the products of digestion (fungi)
Food chain
A sequence of organisms, each of which feeds on the previous one
Food web
Diagram which displays the tropic relationships within ecological communities
Tropic level
Categories of organisms (producer, primary consumer, secondary consumer, etc.)
10% rule of food chains
Only 10% of energy is passed on to the next tropic level in a food chain
Pyramids of energy
A pyramid displaying the amount of energy that is converted to new biomass during a give time period by each tropic level in an ecological community
Biomass
The total quantity or weight of organisms in a given area or volume
Carbon cycle
The series of processes by which Carbon compounds are interconverted in the environment
Greenhouse effect
Natural process in which gasses in the Earth’s atmosphere trap heat radiation from short and long wavelengths of light emitted from the Sun
Anthropogenic factors of enhanced greenhouse effect
Burning of fossil fuels, deforestation, over harvesting of trees, release of CFC’s into the atmosphere and urbanisation
Precautionary principle
When an activity raises the threat of harm, preventative measure should be taken even if a cause-and-effect-relationship has not yet been established (when an activity appears harmful, the activity must be approached with caution, even if those harmful factors have not yet been proven)
Global warming
Gradual increase in the temperature of the Earth’s atmosphere - set to by caused by the enhanced greenhouse effect
Natality
Birth rate (ratio of births to population)
Immigration
The action of coming in to a population
Emigration
The action of leaving a population
Mortality
Death rate (ratio of deaths to population)
Sigmoid population curve
Curve displaying the population change over a given time period
Exponential growth phase (s-curve)
When the population has begun to grow, it rises quickly due to unlimited growth factors
J-curve
Rapid increase in growth of population (population starts to grow in a steady rate, then explodes)
Enhanced greenhouse effect
The increase in natural greenhouse effect as a result of human activities contributing to an increase in concentrations of greenhouse gasses released into the atmosphere
Evolution
The cumulative change in the heritable characteristics of a population
Evidence for evolution
Breeding of domesticated animals and crop plants (significant differences between characteristics of domesticated/wild organisms), fossil records (significant differences between extinct and living organisms), homologous structures (any characteristic of an organism that is derived from a common ancestor), geographical distributions of animals and plants
Natural selection
Process whereby organisms that are better adapted to their environment tend to survive and produce more offspring
Variation
A change or slight difference in condition, favourable traits of variation can lead to natural selection
Sexual reproduction
The production of new loving organisms by combining genetic information from two individuals of two types (sexes)
Antibiotic resistance
Type of drug-resistant microorganism that is able to survive the exposure to antibiotics. This is due to a mutation that inhibits the effects of antibiotics, the favoured gene is then passed on to offspring causing a widespread resistance amongst pathogenic bacteria
Binomial nomenclature
System of naming with using 2 terms, usually inclusive of Genus followed by the species. The terms must be italicised (or underlined) and only Genus is allowed to be capitalised
Transitional phase (s-curve)
When limiting factors in the environment start to limit population growth, thus slowing down population increase
Plateau phase (s-curve)
When the population hits it’s carrying capacity - maximum number of organisms in a population that can be supported by the environment
Speciation
Formation of new and distinct species in the course of evolution
Selection pressures that lead to natural selection
Competition for space, food, mates, increased predation, disease, parasitism
Abiotic
Physical components of a community
Biotic
Living components of a community
Greenhouse gases
Methane, nitrous oxides, CFCs (chloro-fluro-carbons), carbon dioxides and water vapour
Development of antibiotic resistant bacteria
Population with no resistance > resistant gene (by mutation) received from a different population > continuous use of antibiotic causes strong natural selection for resistance > discontinued use of antibiotic causes natural selection against resistance > population with slightly fewer resistance
Species
A group of organisms that can interbreed and produce fertile offspring
