Heterotrichous form:- Presence of more than one type of filament. It becomes multinucleate and a cross wall develops in it. Reproduction in Cladophora: Cladophora reproduces by vegetative, asexual and sexual me­thods. The unit cell parameters obtained with electron diffraction from Cladophora sp. The cell wall of algae is made up of cellulose, hemicellulose, mucilage, pectin and other substances like alginic acid, fucoidin, fucin, calcium carbonate, silica etc. 10, 3O7-3H (1972 30) 7 Printed in Great Britain FINE STRUCTURE OF SWARMER OF S CLADOPHORA AND CHAETOMORPHA II. Taxonomic criteria for the identification Cladophora genera include the following: thallus color, branching types, design and dimensions of the cell, the general structure of the plant, basal cells, and the shape of zoospores (Starmach 1972; Van den Hoek et al. The electron microscopic view of the cell wall reveals that the cellulosic cell wall is made up of cellulose microfibrils which remain variously oriented in a granular matrix. ... Algae attached by well defined root-like structure called a holdfast. Closterium (Closterium sp.) Due to morphological and phenotypical plasticity, many of filamentous algae are difficult to identify. Cell diameter 45-150, length 300 to 1,000 microns. Alternation of generation : A definite alternation of generation occurs in cladophora. Cladophora (Cladophora sp.) Densities of these midges and their effects on Cladophora vary over time (seasonally, over the course of succession, and interannually) and space (down the drainage network). Spirogyra has spiral chloroplasts, but Cladophora does not. 1995). and graze on its algal epiphytes. Many of the cells of the rhizoid become swollen and assume pear-shaped form. Midge larvae (Pseudochironomus richardsoni Malloch) in the South Fork Eel River, California, weave retreats in mats of Cladophora glomerata (L.) Kütz. The total abundance of microalgae and their biomass on Cladophora (per unit area of filaments) varied widely within sampling sites from 3.79 × 10 6 to 5.04 × 10 8 cells … They are both long, rectangular cells that form filamentous colonies. THE CHLOROPLAST D. G. ROBINSON Astbury Department of Biophysics, The University of Leeds, Leeds, LSz gJT, England SUMMARY Freeze-etched chloroplast thylakoid in swarmers s of Chaetomorpha reveal the in situ arrange- The lower cell of the germling acts as rhizoidal cell and the upper develops in a new plant. Cell Set. Good freeze-etch replicas revealing cytoplasm-wall relationships were not however obtained, although with Chaetomorpha the replicas showed J. Cell Sci. E.g.- Spirogyra, Cladophora Cladophora 10. New Cladophora growth is … 9, 581-601 (1971 58) 1 Printed in Great Britain FINE STRUCTURE OF SWARMERS OF CLADOPHORA AND CHAETOMORPHA I. The structure becomes elongated and a wall is secreted around it. Green algae, planktonic (floater) Cladophora forms branched filaments, whereas Spirogyra does not. Green algae, filamentous, attached. structure of a "naked" plant cell, namely the swarmers of the two filamentous green algae Cladophora and C'haetomorpha, with a view to determining how the cellulose microfibrils of the wall are synthesized. In some species during vegetative reproduction the erect por­tion of the thallus dies back, while the rhizoidal system persists. Filament may be branched or unbranched. Filamentous:- Cells arranged one upon the other in a definite sequence forming filament. THE PLASMALEMMA AND GOLGI I APPARATUN S NAKED SWARMERS D. G. ROBINSON AND R. D. PRESTON Astbury Department of Biophysics, The University of Leeds, England SUMMARY J. Siphonous form:- Elongated thallus without septation. E.g.-Draparnaldiopsis Draparnaldiopsis 11.