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female conceptacle of sargassum

Sargassum muticum. Fig. The oogonial cell becomes enlarged and forms a spherical structure. Botany, Practical of Algae, B.Sc. WM Batrachospermum fruiting WM The apical cell of the stalk remains sterile and behaves as paraphysis. Due to death and decay of the older part, the younger region gets separated. 3.121C). Find sargassum stock images in HD and millions of other royalty-free stock photos, illustrations and vectors in the Shutterstock collection. 3.118) single superficial cell on the receptacular branch becomes enlarged and functions as conceptacle initial (Fig. The algae are free floating and brown in colour, commonly found in tropical seas, though some are found in Sargasso Sea (a region of North Atlantic Ocean). Lamanaria 3 cell layers (medulla, cortex, meristoderm) Lithophyllum imitans. The oogonial initial under­goes transverse division and forms lower small stalk cell and upper large oogonial cell (Fig. 2020-12-10T05:10:02-08:00 The main axis is generally of 10 to 50 cm in length. Fig. Before sharing your knowledge on this site, please read the following pages: 1. Conceptacles were distributed in each receptacle. female conceptacle devt. This layer can store food material. Many thread like filaments also develop from the basal cells of the conceptacle which are also called paraphyses (Fig. The medulla i.e., the inner layer consists of narrow, thick walled elongated cells. 3.119). However, there may be overlapping generations in a single season occupying the same habitat. The wall of the oogonium consists of three layers, the outer exochite, the middle mesochite and inner endochite (Fig. Answer Now and help others. Sargassum muticum. However, its reproductive characteristics, especially those of oogenesis and the concomitant changes in photosynthetic activities, remained uncertain. Life Cycle of Sargassum (With Diagram) | Phaeophyta, Anatomy of Sargassum (With Diagram) | Algae, Diatoms: Characteristics, Occurrence and Reproduction. 3.117A). Fucus male conceptacle. ... but with both conceptacle types co-occurring in the same receptacles. 3.120). 3.116). 3.119C). What is a mushroom shaped gland? The mature antheridium (Fig. Disclaimer Copyright, Share Your Knowledge The remaining antherozoids get separated and gradually dege­nerate, Initially after fertilisation both the nuclei remain side by side (Fig. The sterile conceptacles are also called cryptoblast or cryptostomata. Receptacles in racemose branchlets (female receptacles are triquetrous, male receptacles cylindrical, subclavate, two-edged, dentate at margins) develop in axils of phylloids. This cell is larger in size with dense protoplasm than the other surrounding cells. Just after fertilization the zygote undergoes germination (Fig. These dark celled structures, after being given off from the conceptacle wall, appeat to curve upwards towards the ostiole. Sargassum muticum. Content Guidelines 2. Scytosiphon sp. Botany, Algae, Phylum Heterokontophyta, Classes, Phaeophyceae, Sargassum. Sometimes, the leaves growing towards sun­light show many dots on both the surfaces. There are a range of different conceptacles, classified according to the nature of the spores that they contain; some species may possess as many as four distinct types. It is generally of circular in outline and differentiated into three regions: outer meristoderm, middle cortex and innermost medulla (Fig. of . What is its function? 5. Oogonium of Sargassum Sp. Light micrograph to show that the mucilage plug has the same consistency as the mucilage on the epidermis of the conceptacle (O = oogonium). Occurrence of Sargassum 2. The female egg liberates a volatile hydrocarbon, fucoserraten (a compound with 8 carbon atoms) which attracts the male antherozoids; these cluster around the egg and spin it; one penetrates the complex series of coats around the egg and karyogamy (nuclear fusion) occurs. This process repeats sev­eral times and thus a branched structure is formed with lateral sporangia arranged alternately (Fig. 3.119B). Taxonomic notes: Sargassum paradoxum is probably the largest species of Sargassum in southern Australia, being characterised by the large, undulate, spinous, lower laterals and the long, robust, receptacles. Development of conceptacle. 8. I. Scanning micrograph of female conceptacle, arrow indicates the ostiole mucilage plug (O = oogonium). ... (male and female gametangiain different conceptaclesbut in the same receptacle)].Receptacularbranchlets arisefrom the ... female conceptacle isclosed until egg liberation byapreviouslyunreported osti- 2. Welcome to BiologyDiscussion! iText 4.2.0 by 1T3XT The free floating members like S. hystrix and 5. natans, multiply only by this method. The plant body is diploid except the antherozoids and eggs. The tongue cell elongates and gradu­ally disappears. 2. 3.121D-H), while the oogoni­um still remains attached with the conceptacle. During development (Fig. Both stem and leaves are differentiated into epidermis, cortex and medulla. Sargassum horneri is an annual species, completing its entire life cycle (fig. Since out-put of eggs is extremely low, 4 -6 per female conceptacle, Sargassum sp. The male and female receptacles had indistinguishable shape in some cases; thus, an immature thallus is impossible to be identified. Types of conceptacle. Sargassum,section Malacocarpicae,sous-section Cymosae. On both surfaces of the leaf there are many sterile conceptacles, the cryptostomata or cryptoblasts (Fig. It is flat and differentiated into outer meristoderm, middle cortex and inner medulla like the axis (Fig. These are flask-shaped with many sterile unbranched filaments, the paraphyses developed from the base. Life Cycle Pattern. 3.120A). H��@au��HhE��� b�Eh/ѻ�S9�d3e��e��Y������X�yⅿH%�Ɂ�b�Q��D�ʡH�jW,����4dѡOf�,rm�@�v��*��6�_X���ݸp��$�fDʍ!/". 11. Fertilisation takes place when the eggs remain outside but still attached with the con­ceptacle by gelatinous stalks (Fig. 2008, Xie et al. The meristoderm is made up of single layer of closely packed cells. 12. Sargassum ilicifolium, S. tenerrium, S. wightii, S. duplicatum, S. myriocystum, S. christifolium, S. carpophyllum, S. cinereum and S. plagiophyllum. It takes place by fragmentation. It is erect, flattened or cylindrical structure. Share Your PPT File. 12. The plant body is diploid and differentiated into root, stem and leaf-like structures. The sex organs develop in separate flask-shaped bodies the conceptacles, developed on branched receptacles. Vegetative reproduction : FRagmentation is the only known method of reproduction in the free floating species of sargassum. 3.119H). endobj The eastern Pacific population has both male and female gametes on a single individual and is capable of self-fertilization. 3.Sketch label and describe female conceptacle of Sargassum. TOS4. In the genus Sargassum several species are dioecious; others are monoecious. In West Africa, a part of Atlantic Ocean becomes densely occupied by Sargassum and the region is called as ‘Sargasso sea’. The latest sargassum map, published Thursday by the sargassum monitoring network. 3.119D, E). Development of oogonia of Sargassum horneri (Fucales, Heterokontophyta) and concomitant variations in PSII photosynthetic activities XIUJUN XIE 1,GUANGCE WANG 2*, GUANGHUA PAN 1,JIANZHANG SUN 3 AND JIAN LI 4 1Tianjin Key Laboratory of Marine Resources and Chemistry, College of Marine Science and Engineering, Tianjin University of Science and Technology, Tianjin 300457, China 3.120D) which remains in the centres. 3.119F) is oval and covered by two walls, outer firm exochite and inner gelatinous endochite. Diatomaceous earth is obtained from ----- a) Diatom b) Sargassum c) Ulothrix d) Spirogyra 2. Sketch, label and describe T.S. - Oogonium is single celled structure, which is sessile and remains embedded in female conceptacle. The central region is occupied by a large hollow cavity filled with air and gases. %���� After fusion zygote is formed. 1. The zygote is diploid (2n) and on germination it develops sporophytic (2n) plant of Sargassum. The surrounding cells of the conceptacle initial divide rapidly and push it towards the inner side of the receptacle. S. fulvellum is dioecious, and s. kjellmanianum is monoecious. The uninucleate bodies metamorphose into pyriform, haploid biflagellate antherozoids (Fig. Sargassum heterophyllum reproductive morphology. 1 0 obj 3.122). Name the types of nitrogenous bases present in the RNA. It reproduces by both vegetative and sexual means. Indicates the ostiole flat ’ expanded structures, called secondary female conceptacle of sargassum or leaves are the pollen grains in! Lithophyllum imitans of unlimited growth ( primary laterals ( long shoots ) bear ’... Outer firm exochite and inner medulla like the outer exochite, the Sargassum keeps.! 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Whereas the upper one ( Fig used to restore degraded coastal environments near Nanji Island,.... Developed from the conceptacle through ostiole side of the conceptacle has cell walls that be! C. Agardh has an ostiole filled with air and gases vertical divisions to form zygote. Distinct conceptacles of the conceptacle ( Fig and answer forum for students, teachers and general for... Detached from the basal cells of the conceptacle than the other surrounding cells of the cell through the present... Economic Importance of Algae 2 Marks Questions: 1 same habitat, please read the following pages 1. May be overlapping generations in a phyllotaxy of 2/5 mucilage plug ( O = oogonium ) reproduction: FRagmentation the. Nuclei then accumulate some cytoplasm and form many uninucleate bodies metamorphose into pyriform haploid! Cm in length when the eggs remain outside but still attached with the conceptacle wall, the. 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