منابع مشابه
Origin of Alternation of Generations
Alternation of generations is a common component of all land plants, vascular and nonvascular; it does not express itself in the same manner in any other organisms. Given the other overwhelming similarities in land plant biochemistry, photosynthetic pigments and tissue organization, it seems that the easiest assumption is that they are derivatives of a common ancestor. The origin of alternation...
متن کاملSexual conflict and the alternation of haploid and diploid generations.
Land plants possess a multicellular diploid stage (sporophyte) that begins development while attached to a multicellular haploid progenitor (gametophyte). Although the closest algal relatives of land plants lack a multicellular sporophyte, they do produce a zygote that grows while attached to the maternal gametophyte. The diploid offspring shares one haploid set of genes with the haploid mother...
متن کاملAlternation of generations - unravelling the underlying molecular mechanism of a 165-year-old botanical observation.
Characteristically, land plants exhibit a life cycle with an 'alternation of generations' and thus alternate between a haploid gametophyte and a diploid sporophyte. At meiosis and fertilisation the transitions between these two ontogenies take place in distinct single stem cells. The evolutionary invention of an embryo, and thus an upright multicellular sporophyte, in the ancestor of land plant...
متن کاملcausative alternation in persian
in this article, the causative alternation in persian is discussed. first, it is shown that persian anticausative verbs involve a cause component and an implicit external argument. second, we claim that causative alternation arises when a single change-of-state verb invokes more than one semantic frame (fillmore, 1985): causative frame and anticausative frame. these semantic frames are the resu...
متن کاملManner in Dative Alternation
There are a number of well-known restrictions for the Dative Alternation (cf. Green (1974), Oehrle (1976), Gropen, Pinker, Hollander, & Goldberg (1989), Pinker (1989), Pesetsky (1992), Levin (1993). I will show that several of the low-level semantic restrictions are consequences of a more general one involving the incorporation of a manner component into the meaning of the verb. These restricti...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Botanical Gazette
سال: 1906
ISSN: 0006-8071
DOI: 10.1086/328850