CURRENT AFFAIRS

Detailed explanation-1: -Positive-sense single-stranded RNA (+ssRNA) viruses are one such way and it is a key aspect of the infectious cycle of the virus. Two important examples of +ssRNA viruses are severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and Hepatovirus A, which cause coronavirus and hepatitis A, respectively.

Detailed explanation-2: -At the whole-genome level, the SARS-CoV-2 shares an 87.99% sequence identity with the bat-SL-CoVZC45 and 87.23% sequence identity with the bat-SL-CoVZXC2, less genetically similar to the SARS-CoV (about 79%) and MERS-CoV (about 50%) [17].

Detailed explanation-3: -The SARS-CoV is a novel coronavirus with a large ( approximately 30 thousand nucleotides) positive-sense, single-stranded RNA containing 14 functional open reading frames (ORFs) of which 2 large ORFs constitute the replicase gene which encodes proteins required for viral RNA syntheses.

Detailed explanation-4: -Like other coronaviruses, SARS-CoV-2 has a positive-sense single-stranded genomic RNA, approximately 30 kb in length [13], which is among the largest known RNA genomes.