Question

(1.) Describe the structure and replication cycle of T4 Bacteriophage.

(2.) Describe three methods to determine virus concentration other than plague assay and TCID50 assay.

Answer 1

Page No - ☺ Ans - Lilin L structure and replication cycle of T4?- Bacteriophage. - Bacteriophage i sinonimi rolina part bacteriophiaqe is a type of virus that infects bacteria.com | Structure of 74 Bacteriophage - Bikini → Head collar din UAE' isl justice sheath 107.com ili isinii A Tara lb i t o Basal plate in tail fibre. but I iBacteriophageal titi siis i ujin 1 The componenant of The bacteriophage is nucleic acid, either t DNA or RNA and they may be single-stranded or double stranded surrounding by protein structure, 422 Their are three basic structura forms of + phage.

Page - 0 an icosahedral. (20 sided) - Head with tail. © an icosahedral : - Head without tail. | © filamentous form hain 2) The Th bacteriophage iselongated, |: 120 nm long and 86 nm widely 4) is build 3 essential proteins 9223*,qp24 and gp 204. 5) Head also called capsid which contains plasmid contains subunit (protein). (6) 'sheath which contains viral DNA tail fibres. for attachement to the hosts cell.

Page Replication_cycle of Ty Bacteriophage - - Baderiophage initicites DNA .Keplication. in genome During infection a phage attaches to a bacterium of inserting genetic material into the host cell.. phage usually follows two life cycles Lolytic or (virulent) cycle who e lysogenic or temperată cycle - olytic cycle - . these are virulent ic Virus replication: - In the lytic cycle Viral DNA exists. as separåde:free floating molecule in bacterial cell: and replicating seperately from the host bacterial DNA lysogenic cycles In the cycle, within the host DNA : viral DNĂ is located In the lysogenic Gydé attachement Land DNA injecion OCLUIS. -phage DNA not ėmmediately copied or pxpressed to make proteins, viola

steps of 14_life cy de Page ① u Adsorption 2) penetration 2) Transcription 42 Replication s) Assembly 16) Release! celli more than one virus particle adsorb to a single protective coat. viral shii Adsorption a chromosomer e Entrance of the viral chromosome into the host celti penetrazioni Release new particles Tysis of host .المه لما لا thesis of early proleiñ ; Replica of viral DNA. NE l synthesis of a piate proteins / viral DNA covering protective Assembly - multiplication of the Viral chromosome. ப புட்ட