what does a parietal cell form in ovule
Answers
Answer:
Explanation:
Outer layer of secondary parietal cells differentiate to form Endothecium. The inner layer of secondary parietal cells divide to form two layers, one of which forms the middle layers and the other forms the Tapetum. Hence, primary parietal cells eventually form the microsporangial wall inner to epidermis.
Answer:
Explanation:
the ovule is anatropous and bitegmic; the nucellar epidermis is penetrated by the embryo sac; the remaining chalazal part of the nucellus expands, partly due to periclinal divisions in its epidermis; the micropyle is formed by the inner integument only; parietal cells are present; the embryo sac develops according to the Polygonum type; the endosperm is nuclear; after fertilization, the cells of the inner integument enlarge greatly. One difference between the genera is that the inner integument is two cells thick in Dipterostemon , but five to seven cells thick in all Dichelostemma species. In Dipterostemon , embryogenesis is of the Asterad type, and the formation of walls in the endosperm occurs much as in wheat. The absence of variation in embryological characters among the species of Dichelostemma strongly supports the view that these species all belong in one genus, despite differences in gross morphology. Dichelostemma is very closely related to Brodiaea , since species of these two genera show identical embryology. Dipterostemon must be retained as a genus because a deviating inner integument adds to uniqueness in gross morphology. Dipterostemon, Dichelostemma , and Brodiaea , are embryologically quite different from Triteleia. Neither Dipterostemon nor Dichelostemma show any close affinity with Allium.