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SNAB biology hoe > 4A Biodiversity and 5B Climate Change > Flashcards

4A Biodiversity and 5B Climate Change Flashcards

1
Q

why is little genetic diversity bad?

A

increases risk of extinction of population through inbreeding depression

  • no selective adv. when env. changes
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2
Q

why does biodiversity need to be maintained?

A

loss of biodiversity = fewer species = loss of endemic species leads to extinction

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3
Q

how is species richness counted?

A

counting number of species in a known area using quadrat

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4
Q

what needs to be measured in order to compare biodiversity of two diff habitats?

A
  • species richness
    -> for measuring biodiversity WITHIN habitat
    -> count no. of different species and no. individuals in each species
    -> use index of diversity
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5
Q

how is genetic diversity of a species measured?

A
  • 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
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6
Q

niche

A
  • role of species within habitat
  • interactions with biotic and abiotic factors
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7
Q

how are animals adapted to their niche for a higher chance of survival?

A
  • BEHAVIOURAL -> how it acts eg. plays dead
  • PHYSIOLOGICAL -> processes inside body eg. hibernation
  • ANATOMICAL -> structural features eg. streamlined body = faster = more prey caught
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8
Q

biodiversity

A

variety of living organisms in area

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9
Q

how does human activity affect biodiversity?

A

eg. farming and deforestation

decreases species diversity = decreases biodiversity

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10
Q

climax community

A

biggest and most complex community at a stable/steady state

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11
Q

ecosystem

A

all biotic and abiotic factors in area

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12
Q

community

A

all organisms of DIFFERENT species that live in same habitat and interact with each other

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13
Q

population

A

all organisms of ONE species in habitat

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14
Q

describe INTERspecific competition

A

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.
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15
Q

describe INTRAspecific

A

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

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16
Q

how are prey and predator populations linked?

A
  • more prey = more food for predators = more predators
  • more predators = more prey eaten = less prey
  • less prey = less food for predators = less predators
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17
Q

distribution

A

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
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18
Q

what is the Net Primary Productivity

A

rate at which energy is stored in plant biomass

NPP = GPP - R

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19
Q

how do scientists share their data with the scientific community?

A
  • data peer-reviewed by other scientists
  • data published in scientific journals
  • repeats / checking of evidence to ensure validity -> try to replicate results
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20
Q

how does natural selection lead to adaption and evolution?

A

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

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21
Q

what conditions are needed for Hardy-Weinberg equation to work?

A
  • no mutations
  • random mating
  • big population
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22
Q

what is the Hardy-Weinberg equation used for?

A

to predict

  • change in allele freq. in pop over time
  • geno/phenotype freq.

p2 + 2pq + q2 = 1

p + q = 1

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23
Q

species richness

A

no. of DIFFERENT species in one area

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24
Q

explain how breeding programmes in zoos maintain the GENETIC DIVERSITY of captive populations

A
  • animals selected to prevent inbreeding depression
  • STUDBOOK used to select individuals for mating
  • exchange of animals BETWEEN zoos
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25
Q

what are the problems of captive breeding programmes?

A
  • can have problems breeding outside env. -> hard to recreate
  • cruel? to keep in captivity
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26
Q

succession

A

series of changes of organisms present in area OVER PERIOD OF TIME

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27
Q

climate change

A

when weather conditions in region change significantly over a long period of time

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28
Q

what is global warming?

A

increase in global temps due to an increase in GHGs
- GHGs build up in atm -> prevents more long wave / infrared heat radiation from escaping

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29
Q

what are the major problems of global warming?

A
  • 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
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30
Q

dendrochronology

A

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
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31
Q

main GHGs

A
  • CO₂
  • methane
  • water vapour
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32
Q

role of GHGs

A

reduce infrared heat loss from surface of earth

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33
Q

main effects of global warming?

effects = not all bad, some good!!

A
  • 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
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34
Q

what is peat

A
  • 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

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35
Q

what are 4 pieces of evidence for climate change?

A
  • dendronology
  • temp records
  • pollen in peat bogs
  • records of CO₂ levels
36
Q

how can ice cores be used to measure climate change?

A
  • 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
37
Q

what are the causes of anthropogenic climate change? refer to the role of GHGs in the greenhouse effect

A
  • 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

38
Q

how is methane produced? where does it come from?

A
  • 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
39
Q

suggest why climate models aren’t perfect
/ state the limitations of climate models

A
  • 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

40
Q

state 3 human activities that increase atmospheric methane / CO₂ conc

A
  • burning fossil fuels (for industry and cars)
  • farming
  • deforestation
41
Q

what is the greenhouse effect?

A

the increase of global temps caused by the trapping of solar heat by gases in the atm

is this the perfect def??

42
Q

data extrapolation

A
  • process of predicting unknown data using trends in known datasets …
  • … which has many applications eg. predicting changes in climate for future
43
Q

anthropogenic climate change

A

changes in climate caused by human activity

44
Q

kingdom Protoctista

A

eg. algae

  • eukaryotic cells
  • usually live in water
  • single celled or simple multicellular organisms
45
Q

what is the species concept?

A

species in same genus can be v similar

BUT separate species as cannot breed together to produce fertile offspring

46
Q

what are the 3 domains of life based on molecular phylogeny?

A
  • Bacteria (prokary)
  • Archaea (prokary)
  • Eukaryota
47
Q

how is peat used as a source of climate change?

A
  • 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
48
Q

what are the specific climate conditions needed for lots of growth in trees?

to do with denrochronology

A
  • higher temp -> affects enzyme activity
  • more water -> turgidity, p/s
  • mineral ions
  • higher CO₂ conc -> p/s
  • higher light intensity -> p/s
49
Q

suggest ways of reducing carbon emissions that lead to climate change

A

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
50
Q

evaluate the use of biofuels in reducing climate change

A

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
51
Q

suggest some management strategies for climate change

management of conflict between human needs and conservation

A
  • 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)
52
Q

outline the stages of primary succession

A
  1. 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
  2. basic soil = less hostile = more organisms can grow
    -> they die and decompose = leads to soil richer in minerals
  3. richer soil = larger plants growing
  4. at each stage = diff plants better adapted = out-compete existing plants -> making them dominant
  5. leads to climax community (biggest and most complex) in a steady state now
53
Q

molecular phylogeny

A
  • 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
54
Q

explain the difference in primary and secondary succession

A
  • secondary succession already has soil
  • so pioneer species are larger plants
55
Q

explain how peat bogs can be used as evidence of climate change

A
  • 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
56
Q

explain how geographical isolation of a population can lead to 2 diff species

A
  1. allopatric speciation
  2. reproductively isolated -> reduces gene flow / no genetic exchange between pop
  3. pop will experience slightly diff conditions (eg. climates) on each side of physical barrier
  4. pop experience diff selection pressures too -> leads to change in allele freq -> change in phenotype freq -> diff characteristics adv on each side
  5. over time, diff pop beome genetically distinct -> so cannot breed to produce fertile offspring
  6. 2 pop now diff species
57
Q

suggest why reproductive isolation may occur

A
  • 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
58
Q

explain how reproductive isolation (with no geographical barrier present) of a population can lead to 2 diff species

A
  • 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

59
Q

genomics

A
  • 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

60
Q

proteomics

A
  • 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
61
Q

what have scientists learnt through proteomics and genomics research that supports the accepted scientific theory of evolution?

A

-> 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
62
Q

assess the use of seed banks in conserving biodiversity and genetic diversity

A

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
63
Q

describe how seed banks contribute to scientific research and the conservation of endangered species and their genetic diversity

A
  • 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
64
Q

describe how reintroduction programmes in zoos and seed banks can conserve biodiversity and genetic diversity

adv of reintroduction

A
  • 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
65
Q

suggest some problems with reintroduction programmes in seed banks and zoos

A
  • 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
66
Q

describe how seedbanks contribute to scientific research

A
  • 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

67
Q

describe how zoos contribute to scientific research

A
  • 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

68
Q

describe how zoos and seedbanks help to educate people about conserving biodiversity

A

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
69
Q

describe how the genetic diversity of a species can be measured using genotypes

A
  • 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
70
Q

how is species diversity in a habitat measured?

(4 marks)

A

RANDOM SAMPLING -> measuring distribution of organism in area

  1. sample of pop taken
  2. to avoid bias: sample must be random (use rando no. generator for coordinates)
  3. 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

  1. use index of diversity to calc species diversity
  2. repeat process -> take as many samples as possible (gives better indication of whole habitat)
71
Q

explain how the niche concept accounts for distribution and abundance of organisms in a habitat

(2 marks)

A

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
72
Q

sampling can be random or non-random. random sampling removes bias from results.

suggest why non-random sampling is used.

A
  • 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
73
Q

describe systematic sampling and when to use it

A

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)
74
Q

how to measure diff abiotic factors in a habitat

A
  1. climate
    -> rainfall: rain gauge vol of H₂O collected over period of time
    -> humidity: electronic hygrometer
  2. O₂ availability: O₂ sensor (aquatic env)
  3. light inensity: light sensor
  4. soil conditions
    -> pH: indicator with colour change
    -> moisture content: mass soil before and after being dried out in oven
  5. topography (earth’s surface)
    -> height reading using GPS
    -> slope angle: clinometer
    -> aspect (direction slope facing): compass
75
Q

describe how the scientific community critically evaluates new theories

A
  • scientific journals
  • peer review
  • repeat experiments to ensure validity
76
Q

explain why diff ecosystems have diff climax communities

(3 marks)

A

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
77
Q

suggest how succession can be prevented and the name of this type

A

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

78
Q

suggest why NPP might be lower than normal

A
  • when its cold / not lots of light (usually winter) …
  • as p/s is slower
79
Q

NPP also referred to as …

A

energy fixed as biomass

80
Q

% efficiency from one trophic level to the next

A

NPP of next trophic level

÷

energy received (NPP first level)

and x100

81
Q

explain why measuring the diff in energy between 2 trophic levels is not always accurate, including steps to make it more accurate

A

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

82
Q

explain how you would measure energy transfer between trophic levels

(4 marks)

A
  • 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
83
Q

how to calc the average growth rate of seedlings?

cm / day

A

av. change in height in each tray

÷

incubation period

84
Q

Q₁₀

A

rate of reaction at ↑ temp (40℃)

÷

rate of reaction at ↓ temp (30℃)

85
Q

describe a procedure for measuring the initial rate of a catalase-catalysed reaction

(4 marks)

A
  1. boiling tubes with same vol + conc H₂O₂ (+ same vol buffer sol for neutral pH)
  2. set up equipment -> boiling tube + water trough with upside down measuring cyclinder connected with delivery tube
  3. 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
  4. use pipette to add same vol + conc catalase to each boiling tube -> quickly attach bung + delivery tube
  5. record how much O₂ produced (in measuring cyclinder) every 10 secs for 1st min

SNAB biology hoe (15 decks)

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