Determining relatedness of a species Flashcards
Name two molecules that could be compared to show phylogenic relationships
DNA, Proteins
If two species are closely related they will have more/less differences in their sequences of amino acids.
less
If two species are not closely related they will have more/less differences in their sequences of amino acids.
more
When identifying from a phylogenic tree the two species most closely related the success criteria is …?
Comparative term
Mutations accumluate overtime
Quoted differences
Why are we able to use the number of mutations in DNA to indicate evolutionary relationships
Because mutations accumulate over time, Then the more mutations that have occurred indicates a longer time period since divergence
What could we compare in terms of DNA?
Chromosomes
Diploid number.
Gene loci.
Why is it more accurate to use DNA sequence in preference to Amino Acid sequence.
DNA has three times the amount of information and will identify when a silent mutations has occurred.
What are the steps of DNA hybridisation?
The sources of DNA are heated to 90oC to break the hydrogen bonds and separate the strands.
These are then mixed together.
The sample is cooled.
This will form some hybrid DNA.
The sample is then reheated to measure the temperature required to break the hydrogen bonds between the hybrid strands.
Measure the temperature that is required to break the hybrid DNA into single strands.
A higher temperature will be required to break the hybrid DNA back into single strands between more closely related species.
If two species were closely related what would we expect to see in the result of their DNA Hybridisation?
A higher temperature will be required to break the hybrid DNA back into single strands between more closely related species.
If two species were not closely related what would we expect to see in the result of their DNA Hybridisation?
A lower temperature will be required to break the hybrid DNA back into single strands between less closely related species.
