Questions 19 through 21 are based on the merodiploids below. Consider the merodi
ID: 300849 • Letter: Q
Question
Questions 19 through 21 are based on the merodiploids below. Consider the merodiploids below and select all that apply for the question tht e. None of the above Question 19. In the absence of glucose, in which of the above merodiploids is the production of both beta- galactosidase and permease inducible? Question 20 In the absence of glucose, in which of the above merodiploids is the production of beta- galactosidase constitutive while the production of permease is inducible? Question 21 In the absence of glucose, in which of the above merodiploids is the production of beta- galactosidase inducible while the production of permease is constitutive?Explanation / Answer
19) In absence of glucose: There is no merodiploid in which production of both beta galactosidase and permease inducible.
In merodiploid a,there is production of beta galactosidase constitutive and permease inducible.
Here,operator is constitutive,it means there is mutation in operator in such a way that repressor is unable to bind to operator, irrespective of glucose present or absent.So gene Z which code for beta galactosidase costitutively express. There is mutation in Ygene (code for permease) so not express but cell is merodiploid so in another chromosome I+ O+ Z+ Y+ condition which is normal so here production of permease is inducible.
In merodiploid b:Costitutive production of beta galactosidase and production of permease is inducible.Reason similar to above.
In merodiploid c: Production of permease is constitative and there is no production of beta galactosidase.Here in one of the operon, promoter is mutated so no expression of beta galactosidase and permease but in same cell on another operon, operator is constitutive and Y+ is normal so there is constituve expression of permease, but Z is mutated so no expression of beta galactosidase.
In merodiploid d: No production of permease and beta galactosidase because here repressor (is trans acting) is super repressor which binds to operator whether glucose present or absent and inhibit expression of both beta galactosidase and permease.
20) In absence of glucose: In merodiploid a and b,production of beta galactosidase is constitutive and production of permease is inducible.
21) In absence of glucose: There is no merodiploid in which production of beta galactosidase is inducible and production of permease is constitutive.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.