determining relatedness between species

Question 1

what is the purpose of DNA hybridisation

Answer 1

measures the similarity of genetic material and gives an estimate of the genetic distance between species

• the more closely related 2 species are the more complementary their DNA will be.
• The stronger the hybrid molecule will bind, the higher the melting temperature to seperate them

Question 2

the process of DNA hybridisation

Answer 2

DNA from two species is heated (87 degrees)
DNA is cooled to 55 degrees
DNA will anneal
- some will join to another strand of the same species,
- some will join to the same strand of the other species
The mixture is heated again and a UV light is passed through at the same time
There will be two points at which the amount of UV making it through the solution drops
1. where DNA hybrid separates
2. where the DNA from the same species separates
the lower the temperature at which the hybrid DNA separates, the less similar the DNA strands therefore the less similar the species are
- less hydrogen bonds holding complementary base pairs

Question 3

the molecular clock

Answer 3

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