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Adaptation and Selection
Organisms adjusting to suit their environment.
Arises from changes in the DNA from genetic recombination and mutation.
Changes in DNA that result in different characteristics.
A difference in the base sequence may result in a different sequence of amino acids being coded
Different amino acids will cause different polypeptides- hence a different protein or no protein at
Proteins are responsible for the characteristics of an organism.
When one bacterial cell transfers DNA to another.
1. One cell produces a thin projection that meets another and forms a conjugation tube
between the two cells.
2. Donor cell replicates plasmid.
3. Circular DNA is broken to be linear to pass along the tube to recipient.
4. Recipient acquires new characteristic.
HORIZONTAL GENE TRANSMISSION
Transmission of gene from one species to another species.
VERTICAL GENE TRANSMISSION
Transmission of genes from one generation down to next in the same species.
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Each strain is unable to synthesize nutrients needed for growth.
STRAIN 1 needed amino acid methionine, vitamin biotin.
STRAIN 2 amino acid theromine and leucine needed.
They mixed the two strains of ecoli together with all the nutrients.
Bacteria was then removed by centrifugation and washed.
Then it was transferred to a medium without all supplements.
1/10000000 bacteria grew a colony, now having the ability to synthesise all nutrients.
HOW ANTIBIOTICS WORK
It prevents bacteria from forming cell walls.…read more