Form (botany) group with a noticeable morphological deviation. The usual taxonomic practice is that the individuals classified within the form are not necessarily known to be closely related (they may not form a clade). For instance, white-flowered plants of species that usually have coloured flowers can be grouped and named (e.g., as "f. "alba""). Formae apomicticae are sometimes named among plants that reproduce asexually, by apomixis. There are theoretically countless numbers of forms based on minor genetic differences, and only a few that have particular significance are likely to be named. Form (botany) In botanical nomenclature, a form ("forma", plural "formae") is
Calyx of Held embryonic calyx formation. One characteristic that distinguishes Eph proteins and their receptors from other signaling systems is their ability to transmit information bidirectionally. Forward and reverse signaling in VCN and MNTB cells is essential for the proper number and formation of VCN and ipsilateral MNTB projections in the calyx. Eph proteins also ensure that while axons pass through the ipsilateral MNTB, branching and final termination of these projections only occur in the contralateral MNTB, possibly because the proteins are only targeted towards specific regions on the axons. Overall, there are two ultrastructural changes that occur in the calyx of Held.