Aconceptual approach 6th edition mhe/freeman malaria is a life-threatening illness caused by plasmodium parasites that are transmitted to humans by infected anopheles mosquitoes. freitas-junior et al. (2005) describe how multiple plasmadium species evade host immune systems via antigenic variation, wherein the parasites regularly change the antigens on their surfaces to evade detection by host immune cells the mechanism that varies antigen expression is epigenetic: histone proteins associated with a suite of antigen-coding genes are repeatedly chemically modified, such that chromatin structure changes over time, producing variation in expression of particular antigen-coding genes what chemical changes in histone proteins are responsible for changes in gene expression? o o o o a. addition of acidic groups and removal of alkaline groups within the tail domains of histones.
b. removal of electrically-charged functional groups from the tail domains of histones.
c. addition or removal of methyl and acetyl groups within the tail domains of histones.
d. addition or removal of methyl and acetyl groups within the globular domains of histones.
e. proteolytic cleavage of the globular and tail domains of histone proteins into oligopeptides.