Question

Question 59 Not yet answered Which of the listed characteristics is a key difference between prokaryotes and eukaryotes? Points out of 2.50 p Flag question Select one: O a. all of the listed characteristics are shared between prokaryotes and eukaryotes O b. Eukaryotes, but not prokaryotes, undergo DNA replication before cell division O O c. Eukaryotes, but not prokaryotes, perform cell respiration to produce ATP through oxidative phosphorylation d. Prokaryotes, but not eukaryotes, are capable of forming a protective cell wall e. In eukaryotes, but not in prokaryotes, the process of transcription and translation occur in different cellular compartments

Answer 1

Ans 1: In eukaryotes transcription occurs at nucleus and translation occurs at cytosol whereas because of the absence of true nucleus in prokaryotes the transcroption and translation will occur simultaneously at the same position.

Hence option D is the key difference between prokaryotes and eukaryotes.

2: The cAMP Receptor Protein (CRP) is an allosteric protein that is inactive in the free form but is activated by binding to cAMP. The CRP-cAMP complex binds the promoter of inducible operons, increasing the affinity of the promoter for RNA polymerase to stimulate transcription. At high concentration of glucose cAMP levels are low and CRP protein is inactivated which does not increase the transcription level. Thus, the lac operon can only be transcribed at high levels when glucose is absent.

Now here in this case the mutation is preventing CRP protein to bind with cAMP even in the absence of Glucose which means that for this operon the affinity of the promoter for RNA polymerase will not be increased even in the absence of glucose.

So this means these mutants will not express the lac operon genes at a high level.

Hence option B is correct.