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?
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- 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