Paper 2 - Investigating Diversity Flashcards
Comparing the frequency of measurable or observable characteristics
/
Comparing the base sequence of DNA
Members of the same species will have very similar sequences of DNA. Species that have closer evolutionary relationships share a more recent common ancestor will have more similar sequences of DNA in particular gene.
Comparing the base sequence of mRNA
Looking at which part of their genomes are expressed and directly form proteins. This can be used to investigate diversity both between and within species
Comparing the amino acid sequence of the proteins encoded by DNA and mRNA
Organisms that share ardent common ancestor and are more closely related will have similar amino acid sequences when looking at a particular protein.
Uses immunological techniques
Organisms with blood containing similar proteins to humans will result in a greater amount of precipitation when mixed with human antibodies, suggesting they share a more recent common ancestor.
Species richness
The number of different specifies in a habitat
Species diversity
The number of different species and the number of individuals of each species within any community
Index of Diversity
D = N(N-1) / { n(n-1)
D = diversity index
N = total number of organisms of all species
n = total number of organisms of a particular species
{ = sum of
Low Index of Diversity
Few species present and often populations are small
Abiotic (non living) factors are present
Ecosystems are unstable
Only a few species are adapted to survive the harsh conditions
High Index of Diversity
Many species preset and populations are usually large
High diversity of plants and trees = high diversity of insects, animals and birds as there are ore habitats, food source etc
More plants and trees = herbivores colonising the area and then the carnivores will follow
Biotic factors are present.
Ecosystems are stable
