Biodiversity

• What is meant by biodiversity?

  The variety of living organisms in an area, including the range of species in an area and the genetic variety within the species
• what are the two sub factors that determine biodiversity of an area?

  1, species diversity

  2, genetic diversity
• what is meant by species diversity 


  the number of different species, and the abundance of each species within an area
• what is meant by genetic diversity within a species 


  the variation of alleles within a certain species
• what is meant by endemism?

  when a species is unique to a particular place/ area
• what is natural selection 


  the mechanism by which evolution occurs
• what is meant by a habitat 


  The area where a particular organism lives.
• how has species diversity changed as human population increased?

  It has decreased due To the destruction of habitats
• why is conserving biodiversity important? 


  - all organisms are interdependent, so loss of biodiversity in a habitat can affect the balance of food chains

  • genetic diversity is important for adaptation
  • Plants in biodiverse areas are used by humans to produce medicine
  • economic value for tourism
  • indigenous populations depend on biodiversity to maintain their way of life
• what are keystone species? 


  species which have a particularly important impact on the habitat they live in
• what are biodiversity hotspots

  areas which have a very high species richness and contain a large amount of endemic species
• why are biodiversity hotspots usually geographically isolated? 


  1- lack of gene flow allows the evolution of a species which cannot be found anywhere else due to the barrier to gene flow

  2- lack of human disturbance means less habitat destruction

  3-isolation produces a unique habitat leading to different selection pressures and speciation
• why are endemic species vulnerable to extinction 


  they are unable to adapt to new environments or migrate as they are only adapted to one place
• what factor causes endemism?

  isolated land mass
• what types of isolated land masses can form resulting in endemism?

  1 plate tectonics

  2 lakes

  3 islands which form by volcanoes
• what is meant by a species 


  a group of organisms which are able to interbreed to produce fertile offspring
• what is species diversity used for?

  to compare diversity between habitats over time
• what factors is species diversity made up off 


  1- species richness

  2- species evenness
• what is species richness

  the number of different species within an area
• what is species evenness? 


  the abundance of each species in relation to each other within the habitat
• describe how sampling can be used to measure species diversity 


  A random number generator is used to generate coordinates after the area is split into a grid. This is done to avoid bias

  place a quadrant to define the sampling area

  count the number of different species (speciies richness) and the number of individuals of each species

  repeat and repeat using many placed quadrats
• how is the number of species in the total area found using quadrats using an equation?

  total area/ area of one quadrat x mean number in one quadrat
• How can genetic diversity be measured? 


  Using heterozygosity index
• what is the equation for heterozygosity index?

  number of heterozygotes / number of individuals in the population
• How is genetic diversity increased in a population? 


  increase in the different number of alleles in a population, which occurs due to mutations, new individuals entering the population.

  This increases the size of the gene pool
• What is meant by a niche? 


  The specific role that an organism has within it’s environment, including it’s abiotic and biotic interactions
• how many species occupy a single niche?

  one
• what happens when more than one species tries to occupy a single niche? 


  they compete for the same abiotic and biotic factors (resources). the more competitive species is more likely to outcompete the other species and survive and reproduce.
• what happens to the less competitive species occupying the same niche as a more competitive species?

  1- extinction

  2- moving to a slightly different niche in the same habitat

  3- moving to another ecosystem
• what are adaptations? 


  features which allow an organism to carry out it’s niche, and increases the rate of the organism‘s survival and reproduction
• what is a behavioral adaptation? 


  The way an organism acts which increases its Rate of survival and reproduction
• what is a anatomical adaptation 


  structural features which increase chance of survival
• what is a physiological adaptation 


  processes which occur inside the organism‘s body allowing survival and reproduction
• what type of adaptation are courtship actions 


  behavioral (allows to reproduce)
• what type of adaptation are claws and feathers

  anatomical
• what type of adaptation is venom production and ability of cellulose digestion

  physiological
• what is natural selection? 


  the mechanism by which evolution occurs
• what is variation 


  the differences between organisms within a population
• what are selection pressures? 


  changes in the environment which have an impact on the organism‘s survival
• what are examples of selection pressures? 


  1. Predation

  2. Disease

  3. Competition