biodiversity within a community and investigating diversity Flashcards
what is biodiversity
variety of living organisms
can be measured in terms of species diversity (number of species in a community), ecosystem diversity (range of different habitats) and genetic diversity
define community
all the different species that live in one area and interact with each other
how do you calculate index of diversity
d = (N(N-1)) / sum n(n-1)
where N = total number of organisms of all species
where n = total number of organisms of each species
what impact does farming have on species diversity
decreases species richness
- farmland is typically used for only 1 species (monoculture)
- use of pesticides/herbicides
what impact does farming have on genetic diversity
decreases
- farmers select certain characteristics, which reduce number of different alleles in the population
how can biodiversity be increased in areas of agriculture
- use hedgerows instead of fences
- grow different crops in the same area, or rotate crops
- limit use of pesticides and herbicides
name four ways we can compare genetic diversity
- frequency of observable characteristics
- base sequence of DNA
- base sequence of mRNA
- amino acid sequence
what is meant by gene technology
sampling DNA or mRNA in order to read and compare the base sequence of organisms
alternatively the amino acid sequence can be studied as this will also provide information on the organism’s mRNA and DNA sequences
why do scientists prefer to use gene technology instead of observation
simply inferring DNA difference by observing an organism’s characteristics is not reliable; the characteristics could be coded for by more than one gene, or could be influenced by the environment
define interspecific
differences between individuals of different species
define intraspecific
differences between individuals of the same species
what is sampling
selecting a group of individuals to measure that will represent the whole target population
how can a random sample be achieved
create a grid for your sample area, and then randomly generate coordinates where a quadrat or transect can be placed. repeat until required sample size is reached