IF : Transcriptional activator; when present a gene will be transcribed.
WHILE : Transcriptional repressor; gene will be transcribed until repressor is not present.
as stated, IF and WHILE are equivalent (the WHILE is some variation of a contrapositive of an IF)
secondly, it doesn't make sense that a "repressor" would cause transcription unless it is absent, since "
A transcriptional repressor is a protein that regulates gene expression by inhibiting the initiation of transcription".
It is a repressor's PRESENCE that inhibits expression, not it's ABSENCE. Hence it would make more sense to say "Transcriptional repressor; gene will be transcribed until repressor is PRESENT."
secondly, it doesn't make sense that a "repressor" would cause transcription unless it is absent, since " A transcriptional repressor is a protein that regulates gene expression by inhibiting the initiation of transcription".
It is a repressor's PRESENCE that inhibits expression, not it's ABSENCE. Hence it would make more sense to say "Transcriptional repressor; gene will be transcribed until repressor is PRESENT."