The host's memory
does not get passed on to the alien. In resurrection some memory traces etc. were passed on because of the genetic mix between Ripley 8 & the queen chestburster during cloning. As a result, the aliens took on a few basic humanlike qualities, like higher level of intelligence, basic memories, etc.
By default though, an alien will only take on the very most basic physical attributes of it's host, ie: bipedal or quadrupedal hosts will produce a bipedal of quadrupedal alien respectively. On occasion, an alien will take on more specific qualities of the host species, mostly hosts with the most unique DNA patterns, such as predators. In this case the alien will take on a few more specific traits, (such as the predalien's mandibles) etc. But an alien is still an alien, & doesn't carry any memories or thoughts from the host.