Def­i­n­i­tion: The endomem­brane sys­tem includes a group of mem­bra­nous organelles that work togeth­er in a coor­di­nat­ed man­ner to per­form spe­cif­ic […] [...]

Key Con­cept: All organ­isms, no mat­ter how large, begin life as a sin­gle cell. Growth and repro­duc­tion are fun­da­men­tal char­ac­ter­is­tics […] [...]

Overview: The cell cycle varies in dura­tion depend­ing on the organ­ism and cell type. Human cells: ~24 hours. Yeast cells: […] [...]