▁base ▁plate ▁with ▁six ▁tail ▁fib res . ▁The ▁tail ▁fib res ▁are ▁involved ▁in ▁att aching ▁to ▁the ▁host ▁and ▁providing ▁specific ity . ▁ ▁Gen ome ▁The ▁gen ome ▁of ▁the ▁P 1 ▁ph age ▁is ▁moder ately ▁large , ▁around ▁ 9 3 K bp ▁ ▁in ▁length ▁( comp ared ▁to ▁the ▁genom es ▁of ▁e . g . ▁T 4 ▁- ▁ 1 6 9 K bp , ▁lambda ▁- ▁ 4 8 K bp ▁and ▁F f ▁- ▁ 6 . 4 K bp ). ▁In ▁the ▁vir al ▁particle ▁it ▁is ▁in ▁the ▁form ▁of ▁a ▁linear ▁double ▁str and ed ▁DNA ▁mole c ule . ▁Once ▁inserted ▁into ▁the ▁host ▁it ▁circular izes ▁and ▁rep licates ▁as ▁a ▁pl as mid . ▁ ▁In ▁the ▁vir al ▁particle ▁the ▁DNA ▁mole c ule ▁is ▁longer ▁( 1 1 0 K bp ) ▁than ▁the ▁actual ▁length ▁of ▁the ▁gen ome . ▁It ▁is ▁created ▁by ▁cutting ▁an ▁appropri ately ▁s ized ▁fragment ▁from ▁a ▁conc atem er ic ▁DNA ▁chain ▁having ▁multiple ▁copies ▁of ▁the ▁gen ome ▁( see ▁the ▁section ▁below ▁on ▁l ysis ▁for ▁how ▁this ▁is ▁made ). ▁Due ▁to ▁this ▁the ▁ends ▁of ▁the ▁DNA ▁mole c ule ▁are ▁identical . ▁This ▁is ▁referred ▁to ▁as ▁being ▁termin ally ▁redundant . ▁This ▁is ▁important ▁for ▁the ▁DNA ▁to ▁be ▁circular ized ▁in ▁the ▁host . ▁Another ▁consequence ▁of ▁the ▁DNA ▁being ▁cut ▁out ▁of ▁a ▁conc atem er ▁is ▁that ▁a