Nghĩa của từ perisperm bằng Tiếng Việt
@perisperm /'perispə:m/
* danh từ
- (thực vật học) ngoại nhũ
Đặt câu có từ "perisperm"
1. Seeds in which endosperm or perisperm or both exist are commonly called Albuminous or endospermic, those in which neither is found are termed ex Albuminous or exendospermic
2. In the micropylar end of the seed, there are two separate membranous structures; the one closely adhering to the sclerotesta is the unvascularised part of the pleurotesta, derived from the inner layers of the integument whilst the other one represents the remains of the nucellus (perisperm), firmly attached to the female gametophyte and covering the Archegonium chamber.
3. Stevenson (1990, page 20), however, is of the opinion that a tree Coleorhiza is unique to the grasses and that cycads do not have a true Coleorhiza. During germination, the elongating embryo rips a circular segment from the perisperm which can sometimes be seen as a cap on the apex of the ' Coleorhiza ' as it emerges from the sclerotesta (Fig.