Biodiversity

• What is biodiversity 


  The amount of species and relative abundance in a community
• importance of biodiversity 


  important for resilience of ecosystems and sows them to resist changes
• what is ecosystem and habitat diversity

  the range of different ecosystems or habitats within a particular area or region. larger number of habitats within a area then area has a higher biodiversity
• what is species diversity 


  mix of different species that exist within a particular area/ community and can be measured to indicate levels of biodiversity
• what is species richness

  number of species within a community
• what is index of diversity

  the relationship tween the number of species In a community and the number of individuals in each species
• what does a high species diversity produce

  Ecosystems with higher species diversity are more stable than those with lower diversity and more resilient to enviromental changes
• reasons for maintaining biodiversity

  moral and ethical : humans have a responsibility to preserve organisms from going extinct

  ecological : biodiversity increase ecosystem stability

  environmental: organism provide environmental services (absorption of co2 , water and nutrient cycle )

  economic: range of organisms can contribute to medicine ecotourism , science and technology

  agriculture: Diversity can reduce crops from disaster

  Aesthetic : visual effects of diversity nice to look at
• why can species richness be misleading

  as it does not take into account the number of individuals of each species
• equation for index of diversity

  d=N(N-1)/total sum of all n(n-1)

  n= total number of organisms for single species in community

  N=number of organisms in a community

  larger number obtained greater diversity
• Effects of modern farming methods on biodiversity

  have reduced biodiversity as removed hedgerows for more land

  grow monocultures as easier to farm and produce profits

  pesticides and fertiliser reduced biodiversity

  land made arable (able to grow crops) by draining wetland and filing in ponds
• Why do farmers prefer monocultures

  As it provides a higher yield for higher profits
• how can genetic isolation create different species

  two groups of organisms becomes reproductively isolated due to being genetically isolated

  two groups no longer reproduce so do not interchange genes when producing offspring

  changes that occur in allele frequencies of each group not shares so they evolve differently and produce two groups that can no longer successfully interbreed to produce fertile offspring
• what are characteristics that can be measured to classify organisms to investigate diversity

  number of legs

  number of seeds

  number of petals

  colour

  patterns

  habitats

  prescience of wings, hair, fins
• problems of using characteristics to investigate diversity

  Not precise enough as only one characteristic looked at
• why is mitochondrial DNA used to investigate diversity

  no crossing over occurs as all DNA from maternal egg so all mitochondrial DNA in zygote maternal

  no crossing over so base sequence can only be changed by mutation

  scientist can use it to research origins of species , genetic drift and migration

  relies on molecular clock theory which assumes there is constant rate of mutation overtime

  greater differences in nucleotides longer ago common ancestor lived
• How is mRNA used to compare genetic diversity

  Easier to isolate than DNA as found in cytoplasm and multiple clones

  used as template to create complimentary DNA

  unlike DNA cDNA contains only coding regions of gene

  must compare same mRNA between species
• how is amino acid sequence used to investigate genetic diversity

  proteins isolated and amino acid sequence compared

  sequence must be compared between same protein in species

  amino acid sequence of proteins evolve much slower than DNA especially if important proteins
• how is DNA used to compare genetic diversity

  DNA extracted from cell nucleus and base sequence of nucleotides produced

  base sequence compared to other organisms to determine evolutionary relationship

  more similar sequence more closely related
• two methods of sampling to investigate genetic diversity

  Random and systemic
• benefits of random sampling

  mens no bias occurs as points generated at random
• downside of systemic sampling

  points not chosen by random

  individuals could affect results

  does not represent whole area
• why is sampling used

  to estimate distribution and abundance of species in a area

  distribution of a species describes how it is spread through a ecosystem

  abundance of a species is number of individuals of that species
• use of quadrants for sampling

  quadrants laid randomly to avoid as sample bias

  random sampling done by converting area into grid format and giving each grid a number . the use random number generator to get a number

  lay down quadrant and abundance of species can be observed . repeat and scale up results to find estimate of whole area
• limitations of quadrants 


  can only be uses on sessile and immobile species
• what does it mean if a species has a high percentage cover but low frequency 


  species live in groups in preferred areas of habitats
• what is a mean

  average value of data set
• what is mode 


  most common number in results
• what is median 


  middle value in results
• what is range 


  the difference between higher and lowest result
• what Is standard deviation

  measure of spread or dispersion of data around the mean

  small deviation result lie closer to mean

  large deviation results more spread out
• overlaps in standard deviation

  if overlap in standard deviation of results then no significant difference

  in no overlap in deviation then results significantly different
• formula for calculating standard deviation 


  Equation

  
• definition of evolution 


  formation of new species from pre existing species overtime as a result of changes to gene pools from generation to generation