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Flashcards in Determining Relatedness Between Species Deck (13):

What is DNA sequencing?

Determining the exact order of nucleotides in a section of DNA


How is DNA sequencing used to determine relatedness between species?

Sections from 2 organisms similar genes are sequenced and compared, with a number of differences indicative of how related the 2 are.


Why are organisms Mitochondria useful in determining relatedness?

Mitochondria contain their own circular DNA which mutates at a known rate. Only mothers can pass down their mitochondria.


How does the molecular clock work?

As we know the rate at which mitochondrial DNA mutates if we compare 2 organisms mitochondrial DNA the amount of differences/mutations that have accumulated will tell us how long ago the 2 species diverged from one another


How does DNA hybridization determine relatedness between species?

2 samples of DNA are denatured and then mixed and combined together to form a single strand. The strands are then re heated and the temperature at which they denature indicates how many similarities there are in each strands base sequence


What does a high Tm mean?

stronger bonds = less difference between strands = more related


What does a low Tm mean?

Weaker bonds = more difference between strands = less related


What difference in melting temperature corresponds to a one per cent difference in DNA sequence?

1-degree Celsius


What temperature is DNA heated to so the strands separate in DNA hybridization?

87 degrees Celsius


What bonds hold together DNA?

Hydrogen bonds


What does a phylogenetic tree show?

The evolutionary relatedness between species


What is the protein that's level of production affects the Galapagos finches beak formation?



What techniques can be used to make a phylogenetic tree?

Molecular techniques such as DNA sequencing, molecular clocks and hybridisation