Introduction (from Wikipedia). The Archaea constitute a domain or kingdom of single-celled microorganisms. These microbes are prokaryotes, meaning that they have no cell nucleus or any other membrane-bound organelles in their cells. Bacteria constitute a large domain of prokaryotic microorganisms.ut it was discovered that archaea have a distinct evolutionary history and biochemistry compared with bacteria. The similarities are that archaea and eubacteria are single-celled organisms that do not have a nucleus or organelles.
cohort noun [C ]. âº a âgroup of âpeople who âshare a characteristic, usually age: About 42% of women in this age cohort have a college degree. This year's cohort of âgraduates will have particular difficulties âfinding âjobs.ohort noun [C ]. âº a âgroup of âpeople who âshare a characteristic, usually age: About 42% of women in this age cohort have a college degree. This year's cohort of âgraduates will have particular difficulties âfinding âjobs.
Now the cohorts were ten permanent units, composed of 6 centuries and in the case of the first cohort 12 centuries each led by a centurion assisted by an optio. The cohorts came to form the basic tactical unit of the legions.