In the text book for alevel biology A2 on the topic of enzyme marker genes it says:
“If a plasmid with a required gene (DNA fragment) is present in bacteria cell, the colonises grown won’t produce lactase therefore unable change colour. When the gene (DNA fragment) has NOT been taken up my bacteria it will not turn substrate blue”
Surely the bacteria that doesn’t contain the dna fragment will turn blue as the gene is there and the dna fragment isn’t interfering or cutting between that gene of lactase so when it’s put in a substate medium it would turn blue?????
Recombinant DNA technology watch
View Poll Results: Enzyme markers- does no dna fragment in the bacteria mean the lactase will turn blueWhen dna fragment is in bacteria then it doesn’t change to blue but when there isn’t any dna fragment it changes to blue00%Any other suggestion00%