The onset of menstruation is triggered by .

Which of the following accounts for someone who has had regular herpesvirus-mediated cold sore or genital sore flare-ups? a) re-infection by a closely related herpesvirus of a different strainb) re-infection by the same herpesvirus strainc) copies of the herpesvirus genome permanently maintained in host nucleid) copies of the herpesvirus genome permanently maintained in host cell cytoplasm

The consists of a mixture of gases and particles, including oxygen, nitrogen, hydrogen, carbon dioxide, water vapor, and dust.

Which action occurs in the third stage of cell division? a. the nuclear material of cell is copied exactly. b. the nuclear membrane disappears. c. the cell forms two nuclei d. the nuclear material separates, with half moving to either side of the cell.