SACE Biology Flashcards on Ecology, created by R P on 16/11/2014.
Flashcards by R P, updated more than 1 year ago
Created by R P over 9 years ago

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Question Answer
Cell smallest living unit
Organism a single living thing
Population a group of the SAME species living in the ONE location at the SAME time
Community the sum of all the DIFFERENT species living in the SAME location at the SAME time
Ecosystem the sum of all the ABIOTIC and BIOTIC factors AND their interactions
Biosphere all ecosystems combined
Abiotic Factors non-living; physical environment eg, temperature, rainfall, salinity, humidity
Biotic Factors living factors eg. competitors, predators, diseases (parasites and pathogens)
Diversity -the variety of life found on Earth and all of the natural processes; -can be measured by DENSITY or ABUNDANCE
Ecological Groups -producers/autotrophs -consumers/heterotrophs
Producers/ Autotrophs -automatically convert food into energy. -manufacture ORGANIC compounds from simple INORGANIC compounds through abiotic energy sources such as sunlight (photosynthesis) -use the organic compounds themselves for energy and for all other ecosystem members.
Photosynthesis EQUATION *in the presence of sunlight & chlorophyll* carbon dioxide + water = glucose + oxygen
Cellular Respiration (Aerobic) EQUATION *in the presence of oxygen* glucose + oxygen = carbon dioxide + water + ATP
Consumers/ Heterotrophs Obtain energy form eating other organisms or parts of them (plants)
Trophic Level Each feeding level of a food wed
Primary Consumers HERBIVORES -Eat plants or other producers
Secondary Consumers PREDATORS -Eat plant-eaters
Tertiary Consumers Eat predators/ secondary consumers
Consumers can be divided into: -herbivores -carnivores -detritivores -scavengers -decomposers -parasites
Herbivores eat organic matter of producers or their products only eg. honeyeaters
Carnivores eat other consumers {and are predators IF they catch LIVE prey} eg. damselfly
Top Order Carnivore Last link in food chain
Detritivores eat all detritus (decomposing plant an danimal matter as well as waste products) eg. earthworms
Scavengers eat dead animals {specialised detritivores that only eat carrion and animal wastes} eg. vulture
Decomposers break down dead material by secreting enzymes over the organic matter and absorbing the breakdown as food eg. bacteria
Parasites live and feed on other organisms, causing them harm eg. tapeworm
Food chains -shows chemical energy flow or transfer within an ecosystem, beginning with producers. *arrow points to the organism eating/ taking up energy* grass -> grasshopper -> snake -> hawk -> fungi
Food Web shows chemical energy flow or transfer in an ecosystem; compromises of interrelated food chains.
Ecological Pyramids Show the different trophic levels of any ecosystem in a pyramid shape
Number Pyramid Displays the number of individual organisms at each trophic level
Biomass Pyramid Measure the "weight" of biological material at each trophic level {dry weight is used since water content varies greatly}
Energy Pyramid Show energy content of organisms at each trophic level {compared to biomass pyramid as dry biomass tends to have about the same energy content}
Energy Transfer EQUATION [trophic level energy ÷ total energy ] x 100
Amount of energy passed on through each trophic level Approximately 10 %
Intraspecies Members of the same species
Interspecies Members of the different species
3 Types of Interactions -Competition -Predation -Symbiosis
Competition Organisms competing for resources; occurs due to a limited number of resources
Resource any necessity of life, such as water, nutrients, light, food, female attraction
Competitive Exclusion Principle no two species can occupy the same niche in the same habitat at the same time
Niche part of environment where a species can survive, reproduce and persist
Predation when an organism captures and feeds on another organism
Symbiosis any relationship where two species live closely together
3 types of symbiosis -mutualism -commensalism -parasitism
Mutualism both species benefit from a relationship eg. cleaner birds + crocodile
Commensalism one member BENEFITS and the other is NEITHER HELPED or HARMED eg. clown fish + anemones
Parasitism one organism BENEFITS and one is HARMED eg. ticks
Bioaccumulation the progressive accumulation of non-biodegradable/ persistent chemicals in living organisms, becoming more concentrated in HIGHER trophic levels
Species Richness -related to PHYSICAL SIZE of area and LATTITUDE HIGHER in size = HIGHER in richness
Abundance & Density the number of individuals of a given species per unit area
Abundance can be expressed qualitatively by: {ACFOR} -A: abundant -C: common -F: frequent -O: occasional -R: rare
Population Distribution -Uniform -Random -Clumped
Quadrat Sampling Assumptions -The number of individuals in each quadrat is counted. -The size of the quadrats is known. -The quadrat samples are representative of the study area as a whole.
Quadrat Sampling -Used to calculate density, distribution and total size -Used for organisms that are fixed in one place ie. immoblie or sessile
Mark & Recapture Method -Used to study populations where individuals move around a lot ie. mobile -involves catching, marking and releasing the animal, recapturing it and counting no. of marked and unmarked.
Mark & Recapture methods are: tagging; painting; branding; dyeing; attaching ribbons
Mark & Recapture Method Assumptions -the population is closed ie. a population that doesn't change GEOGRAPHICALLY or DEMOGRAPHICALLY (eg. no births, deaths, immigration or emigration) -marked individuals must not become easier or harder to catch -marked and unmarked individuals have sufficient time to mix randomly between time of making and re sampling -animals do not lose their marks
Population Dynamics deals with changes in population size over time
Exponetial Growth -unlimited growth of population eg. r-selected species such as bacteria which replicate through binary fission, introduced species such as rabbits who lack predators since they are introduced -pattern of growth can occur for several generations at least as long as RESOURCES ARE ABUNDANT
Logistic Growth -also known as DENSITY-DEPENDENT GROWTH; population growth in the presence of limiting factors -growth is rapid when population size is below carrying capacity (K) but fluctuates (slows and stops) as size approaches carrying capacity
Carrying Capacity (K) the level at which an environment can support an organism
Natural Selection process in which only the individuals or groups best adapted to their environment survive; survival of the fittest
Gene Pool sum of all the genetic information found within a particular species
Genetic Variability difference in genetic information between the same organisms (meiosis)
Sustainability of human population: current exponential growth can't continue because: -resources are finite -resources are being consumed faster than they are formed -toxic waste is produced faster than it can be broken down
Adaptation anything that helps an organism survive in its environment; helps the organism fulfil the needs of getting food & water, protection and reproduction
Structural Adaptation involves exterior, PHYSICAL feature of an animal's body
Structural Adaptation: Example 1 PROTECTIVE COLOURATION/ CAMOUFLAGE -allow an animal to blend into its environment eg. polar bear
Structural Adaptation: Example 2 MIMICRY -allows one animal to look, sound or act like another animal to fool predators into thinking it is poisonous or dangerous eg. lyre bird
Behavioural Adaptation includes ACTIVITIES that help an animal survive can be instinctive (nature) or learned (nurture) -social behaviour -behaviour for protection
Behavioural Adaptation: Example 1 MIGRATION involves an animal or group of animals moving from one region to another and then back again due to reasons such as: -better food -better climate -safe place to live -safe place to raise young -go back to the place they were born
Behavioural Adaptation: Example 2 HIBERNATION deep sleep where animal's body temperature drops and body activities are slowed to conserve energy eg. bear
Physiological Adaptation related to the INTERNAL functioning of an organism adapting to an extreme environment
Behavioural Adaptation: Examples -specialised organs -chemical senses (organs that pick up hormones) -reproductive physiologies -breeding times eg. fat storage in tail of kangaroos
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