Practice question

Archegonium is characteristic flask-shaped female gametangium found in bryophytes, pteridophytes and gymnosperms, absent in angiosperms where eight-nucleate embryo sac replaces function within ovule. Structure comprises basal swollen venter housing single stationary egg plus ventral canal cell, and elongated neck containing neck canal cells that disintegrate forming mucilaginous passage guiding flagellated sperm chemotactically toward egg via malic acid gradients. Fertilization occurs inside venter providing watery protected microenvironment preventing desiccation. After fertilization, venter wall initially protects developing diploid embryo before capsule expands.