In June 2008, for the first time, the
Year 13 Biology classes amplified chromosomal DNA they had extracted from
plants. The amplification was done using the polymerase chain reaction.
Then the DNA was run in an agarose gel by electrophoresis. The gel works like a sieve,
with small molecules moving quickly from the wells where they started, the large
molecules dragging along behind. This separates them according to size.
A reference ladder of known DNA sizes was run on the same gel to estimate the
sizes of the extracted DNA fragments.
After running the plates for two hours a blue stain was used to make the DNA show up.
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RESULTS: On each side of this gel the DNA ladder was loaded. The sizes of the fragments in base-pairs is given to the left of the bands. All samples were loaded into the wells at the top. The rocket and parsley bands are clear. The onion band is faint. It traveled almost as far as the 510 fragment. The coriander has moved as far as the rocket.
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Year 13 Biology students' prep.
Write a conclusion to this investigation indicating:
which two plants appear to have the closest evolutionary relationship
which appears to be the least closely related to the rest
your estimation of the size of the largest and smallest chromosomal DNA fragments
how the poor onion and coriander results could be improved
