Question

1.Which of the following describes how prokaryotes organize the genes they need to complete a specific task?

		the genes for the task are all located one right after each other on the chromosome; one promoter and one "switch" turns on all the genes at the same time.
		the genes for the task are located on different chromosomes; they all have the same promoter and "switch" located upstream of the genes

2. Which of the following things must happen to a eukaryotic RNA molecule before it can leave the nucleus and be translated into a polypeptide? Choose all that apply.

		introns removed and exons spliced together
		nucleotide cap and tail added
		regulatory RNA binding
		reverse transcription
		translation

Answer 1

1. First option

The genes arranged a prokaryotic chromosome arranged one after the other. They are regulated by a single operator and single promoter. This type of gene arrangement is called as operon. The all the genes are transcribed and translated simultaneously. The messenger RNA form is called as polycistronic because it carries more than one gene.

Second option is incorrect because most of the genes are regulated in unit as operon by a single promoter and they are located on single chromosome. Bacteria is haploid and contains only one chromosome.

2. 1st and 2nd option

The messenger RNA formed after transcription is primary transcript. It is converted into mature messenger RNA before undergoing translation by RNA processing. It includes three steps -

A. Capping - addition of 7-methyl guanosine residue at 5' end by capping enzyme.

B. Tailing - addition of polyadenine tail at 3' end by polyA polymerase enzyme.

C. Splicing - removal of introns and joining of exons.

After the formation of mature messenger RNA, it is ready to enter cytoplasm from nucleus and undergo translation.

Please give a good rating.