Question

2. Which of the following among A-C is false regarding prokaryotic genes and genomes

A. Prokaryotes are generally diploid cell types

B. the structural genes of an operon comprise the regulatory sequences that control gene expression

C. Most prokaryotic genes transcripts are generally polycistronic mRNAs

D. A-C are all true

Answer 1

Q.2. Answer-False statement A. Prokaryotes are generally diploid cell types

Explanation- Prokaryotes are simple unicellular organisms that contain only one single circular chromosome so that we can say that prokaryotes are haploid. Whereas eukaryotes contains more than one copy of chromosomes so that they are diplod or triploid etc. So that it is false that prokaryotes are generally diploid cell types.

True statements-

B. The structural genes of an operon comprise the regulatory sequences that control gene expression - operon in prokaryotes composed of structural gene like promoter, operator, enhancer, silencer that regulates gene expression by affecting RNA polymerase binding to these regulatory genes.

C. Most prokaryotic genes transcripts are generally polycistronic mRNAs- prokaryotes can synthesize more than one protein from one gene that is controlled by single promoter and operator and this type of mRNA is known as polycistronic mRNA. For example in lac operaon lac ZYA synthesizes three proteins regulated by single lac promoter.