Gene Regulation
What is an operon ?
A group of genes under the control of a single promoter (operator)
Which of the following conditions would cause transcription to be activated
A repressor protein deactivated by an inducer
How can DNA methylation affect transcription ?
It may prevent the binding of regulatory transcription factors
On its chromosome , an E coli cell is lac I (-) , lac Z (+), lac Y (+) and lac A (+) . It has an F factor that is lac I (+) , lac Z (+), lac Y (+) and lac A (+). What is the expected level of expression of the lac operon genes ( lac Z (+), lac Y (+) and lac A (+) ) in the absence of lactose?
Neither lac operon would be expressed
Operons involved with the biosynthesis of molecules such as amino acids, are most likely to be regulated in the following manner :
The product of bio synthetic pathway represses transcription
What is an advantage of alternative splicing ?
The same gene can encode multiple proteins
When the lactose repressor is bound to the lactose operon
access to the promoter by RNA polymerase is blocked and transcription of the operon does not occur
The binding of _____ to the lac repressor can cause the lac repressor to ______ to the operator site and thereby _______ transcription
allolactose: not bind: increases
When tryptophan binds to the trp repressor , this causes the trp repressor to _____ to the trp operator and ____ transcription.
bind: inhibit
According to the histone code hypothesis, the pattern of histone modifications acts like a language that...
influences chromatin structure
A repressor is a _______ that ______ transcription
regulatory protein: inhibits
The process of RNA interference may lead to
the degradation of an mRNA and therefore the inhibition of translation
