4A Biodiversity and 5B Climate Change Flashcards
why is little genetic diversity bad?
increases risk of extinction of population through inbreeding depression
- no selective adv. when env. changes
why does biodiversity need to be maintained?
loss of biodiversity = fewer species = loss of endemic species leads to extinction
how is species richness counted?
counting number of species in a known area using quadrat
what needs to be measured in order to compare biodiversity of two diff habitats?
-
species richness
-> for measuring biodiversity WITHIN habitat
-> count no. of different species and no. individuals in each species
-> use index of diversity
how is genetic diversity of a species measured?
- phenotype -> noting observable characteristics you can get an idea of diversity of alleles
- genotype -> samples of organism’s DNA taken and base pairs analysed
->diff order of bases in diff alleles
niche
- role of species within habitat
- interactions with biotic and abiotic factors
how are animals adapted to their niche for a higher chance of survival?
- BEHAVIOURAL -> how it acts eg. plays dead
- PHYSIOLOGICAL -> processes inside body eg. hibernation
- ANATOMICAL -> structural features eg. streamlined body = faster = more prey caught
biodiversity
variety of living organisms in area
how does human activity affect biodiversity?
eg. farming and deforestation
decreases species diversity = decreases biodiversity
climax community
biggest and most complex community at a stable/steady state
ecosystem
all biotic and abiotic factors in area
community
all organisms of DIFFERENT species that live in same habitat and interact with each other
population
all organisms of ONE species in habitat
describe INTERspecific competition
between different species
- competing for same food/habitat
- leads to less resources available for both species
- eg. same food source -> populations limited by this -> less energy for growth and reproduction -> smaller pop.
describe INTRAspecific
within species
- lots of resources = bigger pop. BUT more organisms competing for same amount of food
- limited resources = smaller pop.
- small pop. = less competition -> better for growth and reproduction = bigger pop.
MAX STABLE POP SIZE that ecosystem can support = CARRYING CAPACITY
RA TA TA TAAH in the ghetto the homies stick together
how are prey and predator populations linked?
- more prey = more food for predators = more predators
- more predators = more prey eaten = less prey
- less prey = less food for predators = less predators
distribution
WHERE species is within area
varies due to ABIOTIC factors:
- plants growing on south facing slopes -> where highest light intensity is
- no shoreline plants -> soil too salty
- no large trees in polar regions -> too cold
what is the Net Primary Productivity
rate at which energy is stored in plant biomass
NPP = GPP - R
how do scientists share their data with the scientific community?
- data peer-reviewed by other scientists
- data published in scientific journals
- repeats / checking of evidence to ensure validity -> try to replicate results
how does natural selection lead to adaption and evolution?
M ust
S ell
A ll
C ars
- MUTATIONS -> introduce new alleles = higher genetic variation = variation of characteristics
- SELECTIVE PRESSURES -> eg. predation, disease, competition = struggle for survival
- ADV. CHARACTERISTICS -> increases survival chance -> pass adv. alleles onto offspring
leads to CHANGE IN ALLELE FREQ. (over time) -> adv. characteristics become more common over time
leading to evolution
what conditions are needed for Hardy-Weinberg equation to work?
- no mutations
- random mating
- big population
what is the Hardy-Weinberg equation used for?
to predict
- change in allele freq. in pop over time
- geno/phenotype freq.
p2 + 2pq + q2 = 1
p + q = 1
species richness
no. of DIFFERENT species in one area
explain how breeding programmes in zoos maintain the GENETIC DIVERSITY of captive populations
- animals selected to prevent inbreeding depression
- STUDBOOK used to select individuals for mating
- exchange of animals BETWEEN zoos
what are the problems of captive breeding programmes?
- can have problems breeding outside env. -> hard to recreate
- cruel? to keep in captivity
succession
series of changes of organisms present in area OVER PERIOD OF TIME
climate change
when weather conditions in region change significantly over a long period of time
what is global warming?
increase in global temps due to an increase in GHGs
- GHGs build up in atm -> prevents more long wave / infrared heat radiation from escaping
what are the major problems of global warming?
- enzymes denature at high temp -> affects resp, p/s and other metabolic processes
- bird migration
- feeding / breeding patterns disrupted
- glacier melt / sea level rising -> loss of habitats, niches, food sources
- ocean acidification -> pH decreases, coral bleaching
- increase in extreme weather events -> flooding, forest fires
dendrochronology
using growth rings on trees as historical data for global warming
- trees increase in width as they get older
-
better climate conditions in early summer
= better growth rate (faster cell ÷ and larger cells)
= growth in cambium (meristematic ring of tissue between xylem and phloem)
= thicker rings
pattern of rings tell us how local climate has varied year by year
- as conditions get more difficult = smaller new cells
- eventually growth stops for the year until next spring
-> gives appearance of rings
main GHGs
- CO₂
- methane
- water vapour
role of GHGs
reduce infrared heat loss from surface of earth
main effects of global warming?
effects = not all bad, some good!!
- rising temp
- rising sea level
- changing rainfall patterns
- changing seasonal cycles
- change in distribution of species
- change in development / lifecycles of organisms
- human society -> competition for land, food, fresh water
what is peat
- under waterlogged and acidic conditions
- partly decomposed dead plant matter so packed with organic material
- accumulates and becomes compacted under own weight over time
preserves pollen grains -> can be analysed and used as source of evidence for climate change
what are 4 pieces of evidence for climate change?
- dendronology
- temp records
- pollen in peat bogs
- records of CO₂ levels
how can ice cores be used to measure climate change?
- water freezes and air bubbles become trapped
- CO₂ conc measured
- ratio of diff O₂ isotopes measured -> gives estimate of average air temp when ice formed
what are the causes of anthropogenic climate change? refer to the role of GHGs in the greenhouse effect
- burning fossil fuels
- farming
- deforestation
-> all release CO₂ and methane / increase atm conc of these GHGs
-> which enhances greenhouse effect
-> and causes rise in average global temp a.k.a global warming
how is methane produced? where does it come from?
- anaerobic decay of organic matter in waterlogged conditions
- decay of domestic waste in landfill
- decomposition of animal waste
- produced in dig systems of cattle when they fart / burp
- incomplete combustion of fossil fuels
suggest why climate models aren’t perfect
/ state the limitations of climate models
- limited and extrapolated data
-> IPCC produced models based on several emissions scenarios
-> do not know which of these scenarios is most likely - limited knowledge of climate system
- limitations of tech -> do not know whether future tech will be successful at removing GHGs from atm
check if accurate enough
state 3 human activities that increase atmospheric methane / CO₂ conc
- burning fossil fuels (for industry and cars)
- farming
- deforestation
what is the greenhouse effect?
the increase of global temps caused by the trapping of solar heat by gases in the atm
is this the perfect def??
data extrapolation
- process of predicting unknown data using trends in known datasets …
- … which has many applications eg. predicting changes in climate for future
anthropogenic climate change
changes in climate caused by human activity
kingdom Protoctista
eg. algae
- eukaryotic cells
- usually live in water
- single celled or simple multicellular organisms
what is the species concept?
species in same genus can be v similar
BUT separate species as cannot breed together to produce fertile offspring
what are the 3 domains of life based on molecular phylogeny?
- Bacteria (prokary)
- Archaea (prokary)
- Eukaryota
how is peat used as a source of climate change?
- pollen grains in peat -> can determine what plant pollen came from then what climate can plant survive in?
- deeper the pollen is found = longer ago (in geological time) plants were present
what are the specific climate conditions needed for lots of growth in trees?
to do with denrochronology
- higher temp -> affects enzyme activity
- more water -> turgidity, p/s
- mineral ions
- higher CO₂ conc -> p/s
- higher light intensity -> p/s
suggest ways of reducing carbon emissions that lead to climate change
to reduce Carbon emissions:
- burn biofuels instead of fossil fuels
-> recently living plant biomass eg. sugar cane
-> are carbon neutral -> don’t release carbon stored away for millions of years like fossil fuels do - use of other renewable energy resources
-> wind, solar, geothermal, and tidal energy
-> cheaper to use
-> no CO₂ released
evaluate the use of biofuels in reducing climate change
PROS
- cheaper than oil
- carbon neutral -> don’t release carbon stored away for millions of years like fossil fuels do
- renewable source
CONS
- still release CO₂ into atm -> as burned same way as fossil fuels
- lots of land needed to grow biofuels -> could be used for food production-> so less food produced
- clearing land for biofuel growth leads to loss of habitats / burning produces CO₂
-> bad for biodiversity
suggest some management strategies for climate change
management of conflict between human needs and conservation
-
reforestation -> remove CO₂ from atm via p/s
-> increases p/s
-> carbon captured and converted into carbon compounds and stored in plant tissues in trees -
biofuels
-> produced from biomass -> can be replanted so sustainable
-> carbon neutral
-> use as alternative to fossil fuels (which increases atm CO₂)
outline the stages of primary succession
-
pioneer species colonise new land
-> seeds / spores blown by wind and grow
-> abiotic factors are harsh (no soil) so pioneer species change these by dying and decomposing = humus = basic soil with nutrients - basic soil = less hostile = more organisms can grow
-> they die and decompose = leads to soil richer in minerals - richer soil = larger plants growing
- at each stage = diff plants better adapted = out-compete existing plants -> making them dominant
- leads to climax community (biggest and most complex) in a steady state now
molecular phylogeny
- molecular diff / similarities in seq of bases in DNA and seq of a.a in proteins (molecules)
- to determine how closely related species / organisms are
examples of this: look at …
- size of ribososmes
- structure of cell membrane
explain the difference in primary and secondary succession
- secondary succession already has soil
- so pioneer species are larger plants
explain how peat bogs can be used as evidence of climate change
- pollen preserved in peat bogs
- peat bogs accumulate in layers -> so age of pollen increases with depth
- pollen only produced by mature plants -> so samples only show species that survived the climate
- can extract pollen in peat bogs to see which plants they came from
- climate (eg. temp) affects type of plants growing
- changes in pollen over time indicate change in climate
explain how geographical isolation of a population can lead to 2 diff species
- allopatric speciation
- reproductively isolated -> reduces gene flow / no genetic exchange between pop
- pop will experience slightly diff conditions (eg. climates) on each side of physical barrier
- pop experience diff selection pressures too -> leads to change in allele freq -> change in phenotype freq -> diff characteristics adv on each side
- over time, diff pop beome genetically distinct -> so cannot breed to produce fertile offspring
- 2 pop now diff species
suggest why reproductive isolation may occur
- geographical isolation (allopatric speciation)
-
random mutations -> result in changes below
-> cause changes to alleles and phenotypes that prevent populations successfully breeding (sympatric speciation) -
seasonal changes
-> diff flowering / mating seasons OR become sexually active at diff times -
mechanical changes
-> to genitalia prevent successful mating -
behavioural changes
-> group of individ develop courtship rituals that aren’t attractive to main pop
explain how reproductive isolation (with no geographical barrier present) of a population can lead to 2 diff species
-
diff env in same area (eg. soil pH)
-> ecological - behavioural (eg. diff in feeding, communication or social->mating behaviour)
eg. diff feeding grounds (behavioural) = diff selection pressures = so over time: diff species
genomics
- branch of science -> uses DNA tech to …
- determine base seq of organisms genome
- and functions of its genes
allows scientists to make comparisons between diff organisms’ DNA
proteomics
- study of proteins (size, shape, a.a seq of proteins)
- seq of a.a in protein is coded for by DNA seq in gene
- related organisms have similar DNA seq so similar a.a seq in proteins
what have scientists learnt through proteomics and genomics research that supports the accepted scientific theory of evolution?
-> closely related species diverged more recently
-> evolution caused by gradual changes in base seq of DNA
proteomics
- organisms that diverged away from each other more recently have more similar proteins as less time has passed for changes to occur
genomics
- organisms that diverged more recently have more similar DNA as less time has passed for changes in DNA seq to occur
assess the use of seed banks in conserving biodiversity and genetic diversity
adv.
- cheaper to store seeds than fully grown plants
- so large no. seeds stored than grown plants as need less space
- less labour to look after seeds than plants
- seeds can be stored anywhere as long as cool and dry -> plants would need specific conditions from o.g habitat
- less likely to be damaged by disease / natural disaster / vandalism than plants
disadv.
- testing seeds for viability -> expensive and time consuming
- too expensive to store all types of seeds and regularly test for viability
- may be difficult to collect seeds from some plants as may grow in remote locations
describe how seed banks contribute to scientific research and the conservation of endangered species and their genetic diversity
- store lots of seeds from lots of diff species of plant
- conserve biodiversity by storing endangered plants’ seeds
- so if plant becomes extinct in wild: stored seeds used to grow new plants
- conserve genetic diversity by storing range of seeds for some species with diff characteristics (so diff alleles)
- seed banks create cool, dry conditions for storage so seeds can store for long time
- seed banks test seeds for viability (ability to grow into plant)
-> seeds are planted, grown and new seeds harvested to put back into storage
describe how reintroduction programmes in zoos and seed banks can conserve biodiversity and genetic diversity
adv of reintroduction
- increases no.s in wild -> conserving numbers OR bring species back from brink of extinction
- could also help organisms that rely on these plants/animals as food OR as part of their habitat
- also contributes to restoring lost habitats eg. rainforests that have been cut down
suggest some problems with reintroduction programmes in seed banks and zoos
- reintroduced organisms could bring new diseases to habitats -> harming other organisms living there
- reintroduced animals may not behave as they would’ve if they’d been raised in wild
-> eg. problems finding food / communicating with wild members of their species
describe how seedbanks contribute to scientific research
- study how plant species can be successfully grown from seeds -> helps in reintroducing them to wild
- used to grow endangered plants used in medical research (as new crops / materials)
-> so we don’t have to remove endangered plants from wild
disadv.
-> data may not be representative of wild plants …
-> as only studying plants from seeds in seedbank limits data to small interbred pop
describe how zoos contribute to scientific research
- increases knowledge about behaviour, physiology and nutritional needs of animals …
- contributes to conservation efforts in wild (eg. nutritional / reproductive studies)
disadv.
-> animals in captivity may act diff to those in wild
describe how zoos and seedbanks help to educate people about conserving biodiversity
educating ppl about endangered species and reduced biodiversity helps raise public awareness
- zoos let ppl get close to organisms -> increasing enthusiasm for conservation work
- seedbanks provide training and set up local seedbanks all around the world
-> eg. Millenial Seed Bank Project aims to conserve seeds in o.g country
describe how the genetic diversity of a species can be measured using genotypes
- sample of organism’s DNA taken and base pair seq analysed
- diff order of bases for diff alleles
- by sequencing DNA of individ of same species -> look at similarities / diff in alleles within species
- measure no. diff alleles species has for one phenotype -> to see how genetically diverse species is
-> more diff alleles = greater genetic diversity - also look at heterozygosity index
= no. heterozygotes ÷ no. individ in pop
how is species diversity in a habitat measured?
(4 marks)
RANDOM SAMPLING -> measuring distribution of organism in area
- sample of pop taken
- to avoid bias: sample must be random (use rando no. generator for coordinates)
- count no. diff species (species richness) and no. individ of each species in sample area …
-> plants: quadrat (% cover to measure abundance)
-> flying insects: sweepnet
-> ground insects: pitfall trap
-> aquatic animals: net
- use index of diversity to calc species diversity
- repeat process -> take as many samples as possible (gives better indication of whole habitat)
explain how the niche concept accounts for distribution and abundance of organisms in a habitat
(2 marks)
abundance
- 2 species occupy similar niches will compete (eg. for food) = ↓ individ of each species able to survive in area
distribution
- organisms can only exist in habitats where all conditions that make up their role (niche) exist
sampling can be random or non-random. random sampling removes bias from results.
suggest why non-random sampling is used.
- used in habitats when there is lot of variety in abiotic factors and/or distribution of species …
- so want to make sure all diff areas/species are sampled
describe systematic sampling and when to use it
samples taken at fixed intervals, along a line (using transect) - interrupted transect
to see how organisms (plants) are distributed across an area
- line transects -> taper measure placed along transect and species that touch tape recorded
- belt transects -> data collected along transect using frame quadrats next to each other
- interrupted transects -> measurements at set intervals (eg. point quadrats every 2m)
how to measure diff abiotic factors in a habitat
- climate
-> rainfall: rain gauge vol of H₂O collected over period of time
-> humidity: electronic hygrometer - O₂ availability: O₂ sensor (aquatic env)
- light inensity: light sensor
- soil conditions
-> pH: indicator with colour change
-> moisture content: mass soil before and after being dried out in oven - topography (earth’s surface)
-> height reading using GPS
-> slope angle: clinometer
-> aspect (direction slope facing): compass
describe how the scientific community critically evaluates new theories
- scientific journals
- peer review
- repeat experiments to ensure validity
explain why diff ecosystems have diff climax communities
(3 marks)
temperate climate
- lots of water, mild temp and not much change in seasons
- climax community: large trees as they can grow in these conditions once deep soil developed
polar climate
- not much water available, low temp and extreme changes in seasons
- large trees cannot ever grow in these conditions -> so climax community only herbs/shrubs
suggest how succession can be prevented and the name of this type
human activities
-> when succession stopped ARTIFICIALLY like this = climax community is called a plagioclimax
eg. mowing grass
-> larger plants cannot establish themselves
-> longer interval between mowing = further succession can progress = ↑ diversity
-> only grasses can survive mowing
suggest why NPP might be lower than normal
- when its cold / not lots of light (usually winter) …
- as p/s is slower
NPP also referred to as …
energy fixed as biomass
% efficiency from one trophic level to the next
NPP of next trophic level
÷
energy received (NPP first level)
and x100
explain why measuring the diff in energy between 2 trophic levels is not always accurate, including steps to make it more accurate
consumers (eg mice) might have taken in energy from other sources than producer measured (eg. wheat)
more accurate? -> include all individ organisms at each trophic level
explain how you would measure energy transfer between trophic levels
(4 marks)
- calc diff between NPP of each level
- find NPP by measuring dry mass (biomass) of organisms
-> as energy stored as biomass so indicates how much energy organism contains - dry organisms in oven at low temp -> weigh sample every day until mass is constant = all H₂O removed
- multiply results from sample by size total pop
- diff energy between trophic levels = amount energy transferred
how to calc the average growth rate of seedlings?
cm / day
av. change in height in each tray
÷
incubation period
Q₁₀
rate of reaction at ↑ temp (40℃)
÷
rate of reaction at ↓ temp (30℃)
describe a procedure for measuring the initial rate of a catalase-catalysed reaction
(4 marks)
- boiling tubes with same vol + conc H₂O₂ (+ same vol buffer sol for neutral pH)
- set up equipment -> boiling tube + water trough with upside down measuring cyclinder connected with delivery tube
- put each boiling tube in diff temp water bath (10, 20, 30, 40, 50℃) along with another tube with catalase (enzyme that catalyses breakdown of H₂O₂ -> H₂O + O₂) wait 5 mins
- use pipette to add same vol + conc catalase to each boiling tube -> quickly attach bung + delivery tube
- record how much O₂ produced (in measuring cyclinder) every 10 secs for 1st min
