Ovules have been separated into six categories based on their shapes:
Orthotropous (Atropous): Ovules is straight so that the chalaza, the funicle and the micropyle are all aligned.
Anatropous: Ovules become completely inverted during development so that the micropyle lies close to the hilum.
Hemi-anatropous: Ovules becomes at a right angle in relation to the funicle.
Campylotropous: ovule is bent and the alignment between the chalaza and micropyle is lost.
Amphitropous: ovule is very much curved that the embryo sac and is horseshoe shaped.
Circinotropous: The funicle is especially long that it creates a nearly full circle around the ovule whose micropyle is ultimately pointing upwards.
(Ref. to Fig. 28.2)


pollen tube down through the style. This tube then enters the ovary and reaches the ovule of the plant. Once that occurs, fertilization can arise as the nucleus of the pollen grain is sent
down the tube to merge with the nucleus in the embryo sac. Note that the male alternative to the ovule is pollen, which contains the male gametophytes.