Chap11 Biodiversity Flashcards
Biodiversity
Variety of living organisms in an area
Why do we measure biodiversity?
Important role in conservation
Impact of human activity
How do we measure biodiversity?
Species diversity
Habitat diversity
Genetic diversity
Habitat diversity
Number of habitats in an area
Species richness
Number of different species living in area
Species evenness
Abundance of each species in area
Genetic diversity
Variation of alleles that make up species
What do we measure in random sampling?
Density
Frequency
And percentage cover
Advantage of random sampling
Avoids bias
What equipment do we use for random sampling?
Frame quadrats
Point quadrats
Stratified sampling
Different areas of habitat sampled separately
Divided based on characteristics
Systematic sampling
Samples taken at fixed intervals along line transect
Opportunistic sampling
Samples are chosen by investigator
Data will be biased
How is reliability of data reduced?
By chance
By small sample size
Sweep net
Catch insects in long grass
Pooter
Suck insect into jar
Kick sampling
Disturb water current of aquatic insects
Pitfall trap
Pit in ground insects can’t escape
What is the equation for ESTIMATED POPULATION SIZE?
= ( Total n in first sample x Total n in second sample )
/ Number of marked recaptures
Advantages of mark-release-recapture
Fewer deaths and births
No immigration and emigration
Marked individuals from first sample distribute evenly across population
Disadvantages of mark-release-recapture
Easier to notice marked individual by predator so less likely to survive
Under estimate of population size
Genetic variation
Number of different alleles in given species
What are polymorphic genes
More than one allele
What is the equation for PROPORTION OF POLYMORPHIC LOCI?
= polymorphic loci / total loci
Gene flow
Alleles transferred from two populations
How do we reduce genetic diversity?
Selective breeding
Natural selection
Cloning
Rare breeds
How do we increase genetic diversity?
Sexual reproduction
Meiosis
Mutation
Interbreeding
What is genetic bottleneck?
Selecting alleles by chance.
Results in low genetic diversity.
What is the founder effect?
Migration of small proportion of the population with few alleles.
Results in low genetic diversity.
What is selective breeding?
Breeding desired characteristics
Results in low genetic diversity.
Difference between genetic diversity and natural selection
Genetic diversity happens by chance
Genetic diversity happens in small populations
Natural selection is selection pressures
What is genetic drift?
Change in allele frequency due to individual failing to reproduce OR producing more offspring than others
Occurs by chance.
