True about sex pilus

Ans: a) (Hollow tubular....) Ref: Medical microbiology Jawetz 23nl ed. Baily & Scott's diagnostic microbiology 12th edCONJUGATION* Process where male/ donor bacterium mates or makes physical contact with female/ recipient bacterium & transfers genetic elements into it. 1st described by Lederberg & Tatum in E coli called K12.* Plasmids are the genetic elements most frequently transferred by conjugation. But hostDNA& transposons all can be transferred by conjugation.* Fertility factor carried on plasmid is designated F+. This plasmid confers certain donor characteristics upon cells; these characteristics include a sex pilus: an extracellular multimeric protein extrusion that attaches donor cells to recipient organism lacking F factor.* Plasmid DNA in donor replicates & a copy of it passes from door to recipient along sex pilus. Thus recipient becomes F+& can conjugate with other cells.* Along with plasmid DNA, a portion of host DNA is sometimes transferred.* When F exists in some cells in intergrated state with host chromosome - HFr