15. Central Dogma & Gene Regulation

Which of the following statements is true?

PRACTICE:In prokaryotes, as soon as RNA polymerase synthesizes the 5' end of mRNA, ribosomes come in and initiate translation before transcription is completed. This is called ____.

PRACTICE:_____ allows RNA polymerase to recognize a specific promoter sequence of a gene.

PRACTICE:During which stage of bacterial transcription are sigma (σ) factors involved?

PRACTICE:'Cistron' is another word for 'gene'. Which of these answers are characteristics of polycistronic mRNA?
a) Only found in prokaryotes.  
b) Single mRNA strand, carrying multiple genes.
c) Single mRNA strand can be translated into many proteins.
d) All of the above are characteristics of polycistronic mRNA.

You are provided with cultures with the following characteristics:

Culture 1: F^+, genotype A^+B^+C^+

Culture 2: F ̄, genotype A ̄B ̄C ̄

a. Indicate the possible genotypes of a recombinant cell resulting from the conjugation of cultures 1 and 2.

b. Indicate the possible genotypes of a recombinant cell resulting from conjugation of the two cultures after the F^+ has become an Hfr cell.

Why are the terms gene expression and protein synthesis often used interchangeably?