(n.) The pistillidium or female organ in the higher cryptogamic plants, corresponding to the pistil in flowering plants.
Example Sentences:
(1) It moves down the neck of the archegonium into the cavity above the egg.
Oogonium
Definition:
(n.) A special cell in certain cryptogamous plants containing oospheres, as in the rockweeds (Fucus), and the orders Vaucherieae and Peronosporeae.
Example Sentences:
(1) This immunocytochemical evidence supports the hypothesis that the DNA of the inactive X-chromosome of the human 17-week gestation oogonium is methylated.
(2) In situ nucleic acid hybridization showed that the synthesis of nucleolar DNA begins in oogonium and proceeds slowly through leptotene and zygotene when a small amount of extrachromosomal nucleolar DNA is produced.
(3) These vesicles (V1) are formed originally in unfertilized eggs by smooth endoplasmic reticulum (SER) after release of the eggs from the oogonium.
(4) In connection with this, it is suggested that the term "oogonium" (which is used to designate such cells in the literature) be retained only for proliferating i-cells containing finely filamentous nuclear material in the cytoplasm in the genital zone of the hydra.
(5) In this way, in vitro development from oogonium to larva has been maintained for several generations.
(6) P. diclinum (synonymous with P. gracile sensu Middleton) showed minor differences in vesicle, oospore and oogonium size from P. destruens.
(7) Prior to meiosis in triploid gynogenetic all-female forms of Poeciliopsis, the chromosome number of the nucleus of the triploid oogonium is raised endomitotically to hexaploid.