Final answer:
The embryo sac in angiosperms is homologous with the female gametophyte in ferns and mosses, both being responsible for sexual reproduction and protection of the early embryo, albeit with structural differences.
Step-by-step explanation:
The embryo sac in angiosperms is homologous with the female gametophyte in ferns and mosses. In angiosperms such as flowering plants, the female gametophyte, also known as the embryo sac, develops within the ovule's megasporangium through a process called megasporogenesis followed by megagametogenesis, resulting in an eight-nucleate, seven-cell structure. This includes the egg cell, synergids, antipodal cells, and a central cell that upon fertilization results in the formation of a zygote and endosperm. In ferns and mosses, the female gametophyte is an independent entity that produces egg cells within structures called archegonia. Despite these structural differences, both the embryo sac of angiosperms and the gametophytes of ferns and mosses perform the function of producing the next generation through sexual reproduction and protecting the early stages of the embryo.