The trait that would be least useful in a phylogenetic analysis would be one that a) is detectable only in observations of early development. b) involves genetically inherited behaviors. c) is altered easily by small changes in diet. d) can be studied only in museum specimens. e) is heritable but is determined by many genes.
many human illnesses are caused by infection with either bacteria or viruses. most bacterial diseases can be treated with antibiotics, although antibiotic-resistant strains are starting to emerge. viruses pose a challenge to the body's immune system because they hide inside cells.
it is called periapical abscess