A Nucleus; inside of a cell; inside of a plant or animal cell; inside of a plant <span>or animal; you can take it from there :) :)</span>
Stem cells because they are compatible of dividing and renewing themselves after long periods
A parasite moving between individuals other than parents and their offspring uses
horizontal transmission.
Horizontal transmission is the transmission of infections between (parasites) that are not in a parent-child relationship (vertical transmission). Horizontal transmission may include the carriers or <span>vectors which are other species. Transmission, in that case, occurs via the bite of the vector (an infected organism), like in malaria.</span>
