Biodiversity Flashcards
Define genetic diversity
Number of different alleles of a gene in a population/habitat/community
Define community
All populations of different species in a habitat
Habitat
Places where an organism lives
Define species richness
Number of different species in a community
Define the index of diversity
Describes the relationship between number of species in a community (species richness) and the number of individuals in each species.(population size)
Why is the index of diversity a more useful measure than species richness
Takes into account number of individuals in each species and that some species may have small or high numbers
What does a high index of diversity show?
High species richness
All species evenly represented ( high species evenness)
Ecosystem is more stable and resilient to change.
What does a low index of diversity show?
Habitat is dominated by a few species.
Unstable and less likely to cope with change.
Farming techniques that reduce biodiversity
Removing woodland and hedgerows.
Monoculture.
Use of herbicides and pesticides
Draining ponds and marshes
Overgrazing
How does farming techniques reduce biodiversity?
Reduces variety of plants
Fewer habitats and niches
Less variety of food sources
Balance conservation and farming
Reintroduce hedgerows
Reduce use of pesticides
Rotation of crops and animals
What can farmers use instead of pesticides
Competing species and genetically modified crops
How to investigate diversity of an area?
Separate area into grids
Generate random coordinates
Use a quadrant
Represenative= large sample
Reliable= repeat method and calculate average
How to find population size from quadrants?
Mean no. Of individuals in a quadrant x no. Of quadrants to cover whole area.
How to investigate genetic diversity between or within species.
Compare:
Frequency of measurable or observable characteristics
Base sequence of DNA
Base sequence of mRNA
Amino acid sequence of the proteins encoded by DNA and mRNA
