For the following lac operon haploid genotypes identify the mode of transcription of operon genes and indicate determine whether the strain is lac + or lac- .
Part A:
I+P+O+ Z+Y+
a) is lac- and the genes are inducibly transcribed.
b) is lac + and the genes are not transcribed.
c) is lac- and the genes are not transcribed.
d) is lac + and the genes are constitutively transcribed.
e) is lac+ and the genes are inducibly transcribed.
f) is lac- and the genes are constitutively transcribed.
Part B:
I+P+OC Z−Y+
a) is lac- and the genes are inducibly transcribed.
b) is lac - and the genes are not transcribed.
c)is lac + and the genes are not transcribed.
d) is lac + and the genes are inducibly transcribed.
e) is lac + and the genes are constitutively transcribed.
f) is lac- and the genes are constitutively transcribed.
Part C:
I+P+O+ Z+Y−
a) is lac + and the genes are constitutively transcribed.
b) is lac- and the genes are not constitutively transcribed.
c) is lac- and the genes are inducibly transcribed.
d) is lac + and the genes are not transcribed.
e) is lac- and the genes are not transcribed.
f) is lac + and the genes are inducibly transcribed.
Part D:
I−P+OC Z+Y+
a) is lac- and the genes are constitutively transcribed.
b) is lac- and the genes are inducibly transcribed.
c) is lac + and the genes are inducibly transcribed.
d) is lac+ and the genes are constitutively transcribed.
e) is lac- and the genes are not transcribed.
f) is lac + and the genes are not transcribed.
Part E:
I+P−O+ Z−Y+
a) is lac + and the genes are inducibly transcribed.
b) is lac + and the genes are not transcribed.
c) is lac- and the genes are constitutively transcribed.
d) is lac- and the genes are inducibly transcribed.
e) is lac + and the genes are constitutively transcribed.
f) is lac- and the genes are not transcribed.
Part F:
I+P+OC Z+Y−
a) is lac- and the genes are inducibly transcribed.
b) is lac + and the genes are constitutively transcribed.
c) is lac + and the genes are inducibly transcribed.
d) is lac- and the genes are not transcribed.
e) is lac + and the genes are not transcribed.
f) is lac- and the genes are constitutively transcribed.
Part G:
I+P+OC Z+Y+
a) is lac- and the genes are constitutively transcribed.
b) is lac + and the genes are not transcribed.
c) is lac- and the genes are not transcribed.
d) is lac + and the genes are constitutively transcribed.
e) is lac- and the genes are inducibly transcribed.
f) is lac + and the genes are inducibly transcribed.
I would greatly appreciate an explanation of how to figure out these answers, in addition to the answers themselves, of course. Thank you!