unit 5 - ecology Flashcards
organism definition
any living thing
population definition
group of organisms of same species in same area
community definition
populations of 2 or more different species occupying same geographical area
what is variation
- defining feature of life
- difference b/w members of a group (can be discrete or continuous)
example of discrete vs. continuous variation
blood type vs. body mass/height
purpose of intraspecies variation
enables better survivability of organisms and drives change in species
what does amount of variability depend on
how closely related individual organisms are
- ex. same species = less variability, diff species = large amount of variability
what does species refer to
groups of living things recognizably distinct from all others (biological species concept)
what is morphology
how species were originally groups (based on shapes/structure of organisms)
limitations of morphology
- two groups may look alike but aren’t the same (ex. some butterfly species)
- genetically diverging populations may be hard to distinguish
rules of binomial nomenclature of species
- genus = capital letter
- species = lowercase letter
- name MUST be italicized (underlined it writing)
- after one use, can be abbreviated to first letter of genus + full species name
benefits of binomial nomenclature
- doesn’t vary b/w regions (universally accepted) allowing scientists from different regions to communicate
- reflects evolutionary relationships b/w organisms <– can determine how closely species are related
what is the morphological species concept
when species are classified based on shape/size of individuals
what is the biological species concept
when species are classified as a group of individuals that can breed w/ each other but not w/ other groups
- offsprings must be viable and fertile
if a horse and donkey can produce a mule, why are they not the same species? (based on biological species concept)
- mules are sterile, cannot reproduce
- mules have 63 chromosomes (horse = 64, donkey = 62) so they cannot pair creating non-functional gametes
4 challenges of biological species concept
hybrids
variation across geographical ranges
asexual organisms
testing reproduction b/w groups
challenges of biological species concept - hybrids
offspring can result from sexual reproduction of 2 closely related by separate species which can breed together HOWEVER offspring cannot reproduce
- often seen in plants (artificial breeding b/w species for improved traits)
challenges of biological species concept - variation across geographical ranges
- species are not discrete grouping but approximation
- term “species” doesn’t reflect gradiant of variation within species
challenges of biological species concept - asexual organisms
do not interbreed so biological species concept is inapplicable
- rather classified by appearance, biochemical similarities
challenges of biological species concept - testing reproduction b/w groups
- classifying species involves observing of natural breeding but can be impractical
- ex. deep sea creatures, too hard to observe
- ethical constraints of interfering w/ animals
- not possible for extinct species so must use morphological species concept
species as hypothesis
- species classification is always a hypothesis
- even formally named + described organisms are still hypothesis because new evidence could appear
what is speciation
if two populations of same species don’t interbreed –> physical+behavioural differences accumulate –> can diverge to point of being separate species
- hard to distinguish during process
speciation of brown + polar bears
- closely related but geological locations means they don’t often mate
- speciation can be distinguished to be 1.3-1.6 million years ago
- didn’t stop ability to mate–> climate change creating hybrids
speciation of killer whales
- incredibly hard to distinguish because of similar looks
- diff groups of killer whales are considered diff species not populations because they don’t mate w/ each other
why can’t all organisms of species interbreed w/ each other
reproductive barriers (ex. distance)
population size meaning
total # of individuals –> must be estimated
difference b/w estimate and guess
estimation = based on evidence/random sampling
guess = random
how to get a good sample
every individual of population should have equal chance of being included in sample, avoiding bias
what are samples used for? what is sampling error
making inferences abt entire population
- differences b/w sample statistic and true population value
what is quadrat sampling, how do you find population size from it
repeatedly place quadrat squares in random locations and record # of organisms
- pop size: (average # of individuals per quadrat)x(total # of quadrats)
what organisms is quadrat sampling suitable for
- sessile (non-mobile) organisms –> cannot move b/w quadrats <– prevents them from being count many times
- ex. plants, fungi, very slow moving insects
what does standard deviation mean regarding quadrat sampling
- how evenly distributed population is
- low: population is spread evenly b/w quadrats
- high: population is spread unevenly b/w quadrats (some w/ more, some w/ less)
how does the capture-mark-release-recapture method work, what organisms is it suitable for?
- capture individuals
- mark them
- release them back into habitat
- recapture them and count marked ones
- suitable: mobile organsims
assumptions being made when doing capture-mark-release-recapture mathod
- no migration
- no deaths/births
- marked individuals have same chance of being recaptured as unmarked
- marks remain visible
- marks don’t impact survival
carrying capacity meaning
max population size that environment can support
how is the carrying capacity affect by and how is it naturally determined
- resource availability affects size of population (abiotic and biotic)
- as resources become scarce: competition increases
- as population increases: some individuals cannot get resources –> die
what are the 2 factors affecting population size
density-independent factors
density-dependent factors
what are density-independent factors regarding population size
- has same impact on population no matter population size
- ex. forest fires –> kills everything
what are density-dependent factors regarding population size
- impact depends on population size (larger impact when population size is large)
- ex. negative feedback (population controlling mechanisms) more disease + competition + predation w/ large population compared to smaller one
why are population growth curves exponential, when is it seen
- reproduction is exponential
- positive feedback: breeding –> more individuals = more individuals to breed –> more individuals
- seen when populations enter new habitats (many resources, no predators)
why don’t populations just continue to grow forever
density-dependent factors exist to control population size
what are the phases of the sigmoid population growth curve
- exponential phase
- transitional phase
- plateau phase
what occurs in exponential phase of sigmoid population growth
- population increases more and more rapidly (exponential)
what occurs in transitional phase of sigmoid population growth
- population growth slows as limiting factors start to have larger effects
what occurs in plateau phase of sigmoid population growth
- population remains close to carrying capacity
common pattern in predator-prey population graphs
- cyclical oscillations in predator-prey population sizes (high predator = low prey, low predator = high prey)
four main interactions in predator-prey cycle
- increase prey –> increased food for predator –> increase in predator
- increase in predator –> more predation –> decrease prey
- decrease prey –> less food –> decrease predator
- decrease predator –> less predation -> increase prey
what is top-down control in food chains
interactions that act from higher trophic level to lower one
- ex. increase in predator = decrease in prey
what is bottom-up control in food chains
interactions that act from lower trophic level to higher one
- ex. low minerals in soil = producers cannot grow as much
intraspecific relationships meaning
relationships b/w individuals of the same species –> usually within same population
intraspecific relationships - competition + examples
- members of population share same resources
- unless resource = abundant –> competition occurs leading to some individuals suffering and others benefit
- some individuals are more successful –> natural selection
- ex. plants for sunlight, animals for food, flowers for pollinators
intraspecific relationships - cooperation
- occurs less in plants more in social animals (ex. termites)
- all individuals benefit
- ex. communal roosting, parental care
what is herbivory + examples
primary consumers feeding off producers (which may or may not die)
- ex. rabbits, deer
what is predation + examples
one consumer species kills and eats another consumer species
- ex. tigers, lions
what is mutualism + examples
two species living in close association where both benefit from association
- ex. bees + flowers, clownfish + anemones
what is parasitism + examples
one species living in/on another species and obtaining food from them (parasite benefits, host harmed)
- ex. tapeworms
what is pathogenicity + examples
one species pathogen lives inside another and causes disease to host
- ex. infection bacteria, viruses (?)
what is interspecific competition + examples
two or more species use the same resource, one species reducing the resource of others
- ex. woodpeckers vs. squirrels (fight for nesting holes), cheetahs vs. lions (similar diets)
orchid and fungus as example of mutualism
orchid: supplies carbon compounds + sugars (from photosynthesis) to fungus
fungus: absorbs nitrogen, phosphorus, water, carbon from organic compounds from soil –> supplies to orchid
endemic species definition, how are they controlled?
species that occur naturally in an area and only in that area
- density dependent factors
alien species vs invasive species, why aren’t they controlled?
alien species: those introduced by humans to area –> become invasive when they increase in number and spread rapidly
- population isn’t regulated by natural predators
what is the competitive exclusion principle
two species cannot occupy the same role in an ecosystem forever –> too much competition
red lionfish as example of invasive species
- endemic to parts of indo-pacific
- escaped from aquarium in florida in 1992
- spread to corals in florida +caribbean due to lack of predators, aggressive nature
zebra mussels as example of invasive species
- endemic to black sea region (eurasia)
- arrived in great lakes via ballast water on ships
- spread to ontario, quebec, manitoba
- filters plankton out of water, depleting food source for endemic species
how is quadrat sampling/chi-squared used for testing for interspecific competition?
- by recording presence/absence of species in each quadrat, can test for association (chi squared)
- competitive exclusion –> species rarely found in same quadrat
why choose to do experiments vs. observations
experiments: used when factors must be controlled for result
observations: used when observing species in natural environment
meaning of positive association in chi-squared test + examples
- species are found in same habitat (exists together)
- ex. predator-prey, herbivore-plant
meaning of negative association in chi-squared test
- species occur separately in diff habitats (exists apart)
- ex. competitive exclusion
meaning of no association in chi-squared test
- species occur as frequently together as apart (doesn’t matter whether they are together or apart)
primary vs. secondary metabolites
primary: substances produced by shared metabolic processes in organisms
secondary: substances produced by pathways specific to certain species
are secondary metabolite essential for growth of organism? give examples
- no
- ex. antibiotics, allelopathic agents (biochemicals produced by organism that have negative affect on neighbouring organisms)
what is penicillium, overview of antibiotic production
- genus of fungus found in soil, fruit, bread, cheese
- secretes antibiotic penicillin which interferes with peptidoglycan molecules in cell walls –> become weak and die
habitat definition
- place where organisms live (geographical location)
- the physical conditions/ecosystem type/place in ecosystem
examples of abiotic factors of habitat
temperature, rainfall
biomes definition
groups of similar ecosystems w/ similar abiotic conditions
what is convergent evolution
when plants/animals evolve to have similar adaptations to adapt to similar conditions
- distantly related species that face same probs find same solutions
distribution meaning (regarding species)
where species live in the world
what variables affect plant distributions?
- temperature, water availability, light intensity, soil pH etc.
- the adaptations plants can make to accommodate variables
what variables affect animals distribution?
- water availability, temperature
- can be limited by requirements of life cycle
tolerance meaning (regarding species)
range of tolerance an organism has for abiotic factors
- limiting factor
what is a transect
straight line that cuts through a natural landscape so that standardized observations can be made along it
how does a line transect work
tape a line, any organism touching the line is part of the sample
how does a belt transect work
have a line of quadrants, take data from each quadrant
how does an observational transect work
walk along a defined line and record sightings of target species
required conditions for coral reefs
depth, pH, salinity, clarity, temperature
coral reefs and zooxanthellae mutualism
zooxanthellae needs light for photosynthesis so it can provide coral with building blocks of sugars/proteins, giving it needed nutrients
- corals provide them with a protected environment
ecological niche meaning
the role a species plays in its environment
- because every species has a unique role in an ecosystem
what is a fundamental niche
range of tolerance for the species
- ecological role species plays when there’s no competition
- “where COULD they fit?”
what is a realized niche
actual range covered by species in ecosystem
- ecological niche actually occupied by species w/ competition
-“where do they actually fit”
what does ecological theory state
that all species in an ecosystem must have a unique realized niche
how are realized niches exposed
when fundamental niches of two species overlap, competition <– where one species will win over the other
what happens when fundamental niches completely overlap and one species always outcompetes the other?
the underperforming species will be eliminated from the whole ecosystem
adaptation definition
a change/process of change by which organism/species becomes better adapted to its environment
adaptations of lyme grass to sand dunes
- sand dunes have little water + organic matter, high salt –> dehydration occurs
- LG: thick waxy cuticle to reduce transpiration
- leaves roll up during droughts >humid chamber reduces SA
- rhizomes (underground stems) grow upwards as sand accumulates and extend deep into dune obtaining water
adaptation of mangrove trees to mangrove swamps
- mangrove swamps have waterlogged anaerobic soils w/ high salt content
- MT: secretion of excess salt from salt glands in leaf
- root epidermis coated in cork->less permeability to salt
- vertical root branches grow vertically into air to absorb O2
- stilt roots grow downward supporting tree in the mud
- large buoyant seeds –> carried by away currents
abiotic factors of hot deserts
- high daytime temps, colder nights
- low rainfall, long periods of drought
how does saguaro (cactus) adapt to hot desert environment?
- wide spreading + deep root system (max water absorption)
- fat stems w/ storage tissue
- pleated stems to allowing growing in rain shrinking in droughts
- CAM metabolism (open stomata at night to reduce transpiration)
how do fennec foxes adapt to hot desert environment?
- nocturnal +builds den underground (less extreme temps)
- thick hair for insulation
- light coat colour (absorbs less sun)
- large ears (high SA for cooling)
- ventilation rate can be 600 breaths/min (panting = regulated temp)
abiotic factors of tropical rainforests
high temps, high precipitation, light light intensity
how do meranti trees adapt to tropical rainforests?
- hard, dense trunks to protect against winds
- enzymes tolerate 35C for optimal performance
- broad oval leaves + smooth trunk to shed rainwater
how do spider monkeys adapt to tropical rainforests?
- long hook-like arms/legs for climbing
- flexible shoulders + long tail
- developed larynx that is louder in dense rainforest
hominidae family
great ape family, includes humans, orangutans, gorillas, cimpanzees
how is the hominidae family and dentition related
- herbivores: large flat molars to grind down plant tissue
- omnivores: flat to grind plant tissue + sharp to tear meat
- can infer diet of extinct species by looking at teeth
what adaptations of beetles+aphids (herbivores) allow them to feed on plants
beetles: jaw-like mouthparts for biting off, chewing, ingesting leaves
aphids: tubular mouthparts for piercing leaves/stems to reach phloem and feed on sap
what adaptations do some plants have to resist herbivory
- tough, sharp pointed spines
- synthesizes toxic substances <– secondary metabolites
- however some herbivores have adaptations to detoxify them
physical/structural adaptations
- take longer to develop
- genetic change
chemical adaptations
- take longest to chance
- new enzymes may be needed/new ways needed to regulate enzymes
behavioural adaptations
- can change relatively quickly
examples of physical/structural adaptations
- teeth shape (vampire bats)
- camouflage (moths)
examples of chemical adaptation
- venom (black mambas)
- accumulation of toxic alkaloids from diet (caterpillars of cinnabar moth)
examples of behavioural adaptation
- ambush strategies to catch migrating salmon (grizzly bears)
- swim in tight groups (snappers)
what are adaptations plants have for harvesting light?
- when water/temp is suitable, plants compete for light
- some trees grow to great heights
- lianas climb up other trees (no trunk)
- epiphytes grow in trunks/branches
- stranger epiphytes climb up tree trunks, outgrowing them
- shade-tolerant shrubs rest on forest floor
what are obligate aerobes? examples?
- organisms that require a continuous oxygen supply so only live in oxic environments
- ex. all animals + plants
what are obligate anaerobes? examples?
- organisms that are inhibited or killed by oxygen so only live in anoxic environments
- ex. tetanus bacteria, methanogenic archaea
what are facultative anaerobes? examples?
- organisms that use oxygen if available to live in oxic or anoxic environments
- ex. e coli, yeast
energy in open ecosystem+ examples
energy and matter enters ad exits
- ex. savannahs, grasslands
energy in closed ecosystem
only energy exits/enters
- ex. aquariums, bottle gardens
how much light is harvested by producers in sahara desert
- little although high light intensity, because little number of producers
how much light is harvested by producers in marine ecosystems
- light has hard time penetrating water so not a lot
- cloudy waters block light more
chemosynthesis meaning
using chemical reactions to create carbon compounds
what producers can obtain energy in dark caves? how?
archaea - gains energy from chemical reactions using methane, sulfides, other inorganic compounds as substrates
what are archaea?
- one of three domains (bacteria, eukarya, archaea)
- prokaryotic cells
- adapted to extreme environments
diversity of nutrition in archaea
can obtain energy by -
chemotrophic: oxidation of inorganic molecules
phototrophic: absorption of light by pigments
heterotrophic: oxidation of carbon compounds obtained from other organisms
what is the first law of thermodynamics
energy cannot be created or destroyed, only transferred or transformed
what are laws? what are they based on? what are they used for?
- generalized principles made to describe patterns observed
- based on repeated observations
- more obs = more supported law
- used for making predictions
difference b/w laws and theories
laws describe, while theories explain
how do autotrophs synthesize carbon compounds
- using external energy sources (light/chemical reactions)
- use CO2 or HCO3 as carbon source to create all required carbon compounds
what do oxidized substrates do, what are they involved in
release energy that drives endothermic reactions
- calvin cycle in photosynthesis, condensation rxns
photoautotroph vs. chemoautotroph
uses light energy vs. uses chemical rxns (oxidation rxns) as external energy sources
how do heterotrophs synthesize the carbon compounds they require
- obtains carbon compounds from other organisms
- digests those carbon compounds + uses product of digestion to build necessary carbon compounds
assimilation meaning
process of absorbing carbon compounds into cells and making them part of the body
what are holozoic heterotrophs
- digestion occurs internally
- includes most animals
process of nutrition in holozoic heterotrophs
ingestion, digestion, absorption, assimilation, egestion
consumers meaning
feeding on living/recently killed organisms (includes herbivores, carnivores)
detritivores meaning
feeds on dead organic matter (ex. worms, millipedes)
what are mixotrophic heterotrophs + 2 types
organisms that are both heterotroph and autotroph
- facultative mixotrophs vs. obligate mixotrophs
what are facultative mixotrophs + example
- organisms that can be entirely autotrophic, entirely heterotrophic or both
- ex. euglena <- contains both chloroplasts for photosynthesis and performs endocytosis for consumption
what are obligate mixotrophs + example
- organisms that must use both autotrophic and heterotrophic nutrition
- ex. carnivorous plants <-protists that can photosynthesize but not photosynthesize all carbon compounds
how do saprotrophs (decomposers) obtain nutrition + examples
- secretes digestive enzymes onto dead organic matter -> digests externally then absorbs the products of digestion
- ex. many types of bacteria, fungi
what organisms need ATP? 4 reasons
- all organisms require cellular energy
- to synthesize molecules
- for active transport
- for moving cellular structures
- for maintaining body temp
how is ATP produced from cell respiration
carbon compounds oxidized to release energy-> phosphorylates ADP into ATP
food chain definition
sequence of organisms which each feed on the previous one
where are producers/consumer located on food chain, what are arrows used for
1st: producers
everywhere else: consumers
- to show the flow of energy
what are trophic levels
where organisms are positions in a food chain
what is a food web
summarizes all possible food chains in a community
what are energy pyramids
- shows amount of energy gained per year by each trophic level
formatting of energy pyramid
- title
- units: kJ/m^2yr (energy per unit area per year)
- stepped shape
- producers @ bottom
- labelled by trophic level
- if scale used, bars = proportional
what is primary production
accumulation of carbon compounds in biomass by autotrophs
- primary producers convert light + inorganic nutrients->organic biomass
what is gross primary production (GPP)
total biomass of carbon compounds made by plants in photosynthesis
what is net primary production (NPP)
gross primary production – biomass lost due to cellular respiration
what is secondary production
accumulation of carbon compounds in biomass by heterotrophs
- carbon compounds ingested -> converted into macromolecules
- decreases at each trophic level
how much energy is reduced b/w trophic levels, 3 reasons why?
- 10% energy is passed down from each trophic level
- cell respiration: carbon compounds consumed and turn into waste product
- incomplete consumption: not all parts of organism are eaten b/w levels -> remains consumed by saprotrophs = leaves food chain
- incomplete digestion - not all ingested food is digested/absorbed, some is egested and leaves food chain
heat loss to environment in autotrophs and heterotrophs
- ultimately, energy in food chains converts to heat
- all organisms convert some chem energy -> heat to maintain body temp, side-effect of cell respiration, heat generated from ATP usage
- heat lost to environment cannot be converted back into chemical energy and recycled
how are number of trophic levels restricted due to energy loss
- less biomass available to consumers at higher trophic leves <- hard to find prey,- limits pop size
pool meaning - carbon cycle
reserve of carbon
flux meaning - carbon cycle
transfers from one pool to another (ex. photosynthesis, feeding, respiration)
carbon sink vs. carbon source
ecosystem has net uptake of CO2 vs. ecosystem has net release of CO2
carbon sink: natural gas and oil, when + how was it formed
- when: over 550M years ago
- how: deep buriment of partially decomposed organic matter <- high temp cause chem changes
carbon sink: coal, when + how was it formed
- when: 250-325M years ago
- how: accumulation of wood+ other plant material from swaps<- buried under other sediments
carbon sink: peat, when + how was it formed
- when: 10,000 years ago
- how: incomplete decomposition of dead plant matter<- due to acidic + anaerobic condition in swamps/bogs
carbon sink: biomass when + how was it formed
- when: accumulated over past thousands of years
- how: plant biomass derived from photosynthesis with transfer along food chains giving animal biomass
what does keeling curve do, what causes fluctuations
tracks the atmospheric CO2 levels
- changes in abiotic factors (temp, weather, rainfall) <- ultimately affecting carbon cycle
relationship b/w photosynthesis and aerobic respiration, what does this mean?
- positive feedback loop
- originally O2 levels on Earth = low
- evolution of photosynthesis-> inc O2 levels on earth
- allowed evolution of aerobic respiration -> inc. CO2 levels
- allowed more photosynthesis
- means: autotrophs and heterotrophs rely on each other for O2 and CO2
