stream Sargassum species are mostly monoecious. Ist year, Paper-I, Sem. The spores develop into haploid male or female gametophytes, which eventually produce the sexual gametes. Fucus female conceptacle VS Padina thallus WM Sargassum thallus (leaf) TS Sargassum male conceptacle TS Sargassum female conceptacle TS Sargassum bladder TS Laminaria Thallus TS Laminaria Receptacle VS Rhodophyceae (Red Algae) Amphiora WM Batrachospermum Veg. Sargassum shows diplontic life cycle without any alternation of generations (Fig. Sargassum shows diplontic life cycle without any alternation of generations (Fig. ensures its survival under all eco-physiological conditions. For example, Lithophyllum incrustans bears asexual, male, female and cystocarpic (strictly, a type of female) conceptacles, discussed below. After meiosis oogonia and antheridia, the female and male reproductive organs, produce egg cells and sperm respectively that are … Scale = 100 ltm. Yeast: Origin, Reproduction, Life Cycle and Growth Requirements | Industrial Microbiology, How is Bread Made Step by Step? 3.119B). Department of Botany, DAV College, Jalandhar (PB.) 3.120C). The sub-genus Sargassum ... 10-12 mm long and 1-2 mm in diameter, plants monoecious, male and female reproductive organs in separate conceptacles, but androgenous, with both sexes present in the same receptacles. I. Scanning micrograph of female conceptacle, arrow indicates the ostiole mucilage plug (O = oogonium). 3.119D). 2008, Xie et al. 10. What is a mushroom shaped gland? The eastern Pacific population has both male and female gametes on a single individual and is capable of self-fertilization. The main axis is generally of 10 to 50 cm in length. In transverse sections of receptacles of S. kjellmanianum, male and female organs were found in distinct conceptacles of the same receptacle (Fig. Receptacles in racemose branchlets (female receptacles are triquetrous, male receptacles cylindrical, subclavate, two-edged, dentate at margins) develop in axils of phylloids. The medulla is round and present in the middle region. Answer Now and help others. 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. dark pink ceramic glaze. The mature female and male receptacles of S. thunbergii were dumpy and acerose, respectively (Figure 2). The plant body is diploid and differentiated into root, stem and leaf-like structures. However, its reproductive characteristics, especially those of oogenesis and the concomitant changes in photosynthetic activities, remained uncertain. endstream What is the significance of transpiration? Sargassum resource is heavily destroyed and scarce in Northern China be- ... appeared in mature female conceptacle. The apical cell of the stalk remains sterile and behaves as paraphysis. 3.121C). The conceptacles bear sex organs. Just after fertilization the zygote undergoes germination (Fig. Every stage of development in both structures is the same, from the appearance of the similar initial cells to the development of paraphyses in the cryptostomata and sexual organs in the conceptacle. Like the outer layer this layer also stores food material. It is flat and differentiated into outer meristoderm, middle cortex and inner medulla like the axis (Fig. Instead it reproduce by vegetative method and the formation of sex organs. Both stem and leaves are differentiated into epidermis, cortex and medulla. Sargassum muticum. • Development of sex organs. 13. Since out-put of eggs is extremely low, 4 - 6 per female conceptacle, Sargassum sp. 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. %���� For male it is called as Antheridia whereas in female it is called Oogonium. Vegetative reproduction takes place by frag­mentation. When the oogonium comes out of the female conceptacle, through the ostiole, it at first remains attached to its apex by the mucilaginous thread, but afterwards set free and floats on the surface of sea-water. 3.121A). Share Your PPT File. 11. 13. Life Cycle Pattern. Conceptacles were distributed in each receptacle. The male and female receptacles had indistinguishable shape in some cases; thus, an immature thallus is impossible to be identified. 3.120B). Zygote germinates directly and produces a new sporophytic (2n) plant. The separated region grows and finally develops into a new individual like the mother. On both surfaces of the leaf there are many sterile conceptacles, the cryptostomata or cryptoblasts (Fig. It is generally of circular in outline and differentiated into three regions: outer meristoderm, middle cortex and innermost medulla (Fig. 3.122). 4 0 obj Diatomaceous earth is obtained from ----- a) Diatom b) Sargassum c) Ulothrix d) Spirogyra 2. What is its function? Fucus monoecious conceptacle. The main axis and primary laterals (long shoots) bear flat’ expanded structures, called secondary laterals or leaves. After coming out, the wall of sporangium gets gelatinised and the antherozoids are liberated. 3.120A). This layer possibly helps in conduction. WM Batrachospermum fruiting WM The conceptales with antheridia or oogonia are called male or female conceptacles. Most of the species of Fucales reproduce sexually except Sargassum natans and Sargassum fluitans, which reproduce only by fragmentation (Lee, 2008).Reproduction is of oogamous type and reproductive structures in Fucales are borne in a special flask-like cavity, which is known as conceptacle. Due to death and decay of the older part, the younger region gets separated. The air bladders help to float them in water (Fig. The holdfast is discoid and serves the func­tion of anchorage with the substratum. 3.Sketch label and describe female conceptacle of Sargassum. TOS4. Vegetative reproduction : FRagmentation is the only known method of reproduction in the free floating species of sargassum. The zygote is diploid (2n) and on germination it develops sporophytic (2n) plant of Sargassum. Sargassum muticum. Features 5. The diploid (2n) nucleus undergoes first meiotic (Fig. Fertile cavities, the conceptacles, containing the reproductive cells are immersed in the receptacles near the ends of the branches. The free floating members like S. hystrix and 5. natans, multiply only by this method. The antherozoids and eggs i.e., the gametes, represent only the haploid (n) stage. The oogonial cell becomes enlarged and forms a spherical structure. This layer can store food material. Share Your PDF File 3.119C). Find sargassum stock images in HD and millions of other royalty-free stock photos, illustrations and vectors in the Shutterstock collection. Reproduction takes place by vegetative and sexual means. Development of conceptacle. The Female Conceptacle and Young Sporeling of the Four New Zealand Species of Carpophyllum By Margaret Naylor, Otago University [Read by title before Otago Branch on July 14, 1953; received by Editor July 27, 1953.] Each one divides by a transverse wall into two cells. 303_1.tifAdministrator Privacy Policy3. endobj female conceptacle devt. This website includes study notes, research papers, essays, articles and other allied information submitted by visitors like YOU. - At maturity, it is discharged through ostiole. 2. But no matter how much money is forked out, the sargassum keeps coming. Asexual reproduction is absent. The antherozoids and eggs i.e., the gametes, represent only the haploid (n) stage. Our mission is to provide an online platform to help students to share notes in Biology. 2. Botany, Practical of Algae, B.Sc. 3.119). �@�G�@��0�w��]��d:�� ���Z'䃴�M����ѱ��/���x������iWY+\�j���S�C�ӆ>��x�;���?��w�YZ�`���*��. These dots are the ostioles i.e., openings of the sterile conceptactes. of . Chapter: 6 Economic Importance of Algae 2 Marks Questions: 1. What are the general characters of bryophytes? The genus Sargassum (Spanish sargazo, sea­weed) is represented by about 150 species, out of which 1 6 species are found in India. Reproduction 7. 3.117B). Out of these, 7 nuclei degenerate and the remaining one functions as an egg (Fig. The cells are smaller in size than meristoderm. Asexual reproduction is absent. • Fertilisation. Some of the cells of this layer function as an oogonial initials (Fig. 3.120E). It serves the function of anchorage, photosynthesis, storage, conduction and support. The zygotic cell settles down and germinates to form a new diploid thallus. Sketch, label and describe T.S. 3.119H). The remaining antherozoids get separated and gradually dege­nerate, Initially after fertilisation both the nuclei remain side by side (Fig. <>stream 3.118A). The antheridial cell develops into an antheridium (Fig. The medulla i.e., the inner layer consists of narrow, thick walled elongated cells. The Conceptacles. Thousands of new, high … Sometimes, the leaves growing towards sun­light show many dots on both the surfaces. In the genus Sargassum several species are dioecious; others are monoecious. 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. After fusion zygote is formed. The tongue cell elongates and gradu­ally disappears. 3.117A). 7. 3.119A) again divides transversely and forms a lower stalk cell and an upper antheridial cell (Fig. 3.117C). Sargassum,section Malacocarpicae,sous-section Cymosae. After fusion zygote is formed. The zygote then divides transversely and forms lower and upper cell. The nuclei then accumulate some cytoplasm and form many uninucleate bodies. 3.119D, E). Fig. Which organelle is known as “power house” of the cell? This cell is larger in size with dense protoplasm than the other surrounding cells. 8. The cells are meristema- tic in nature. These are flask-shaped with many sterile unbranched filaments, the paraphyses developed from the base. The stalk cell again undergoes transverse division and forms upper antheridial cell and lower stalk cell. x��Xˎd5��W�qޑ�H�D�Zb�X~۱�ܪ� 4��ҕ���籓?`�}B?5��������h�)1����|8=>��f�yz?�C|n-�d��!�֚����|��s�9Gl��\���;���Y��� GhY�٫��j�E�'l�6˯����7���ޘ~]hDž^����O���i��ɹ�- Z����ӗ�Z��>��J5���B� ۱7ߴ�3ё�ܵ�^%]E��_�z��5ㅪh�A�4��td��]��-�ź�[Z^��Vu���; �{��E|�������l����:'� }�E�G,@B��g�C^�~�-����t�S�/C��o��u%&�}�t~4��up��,'~�R6oki4���G�p6���,��_Ǫ��A��-�����׷� � +K� ࣸ���+����R �^惸m��]w���@��zϻG�(dgW�w ���$$���4�= 1 0 obj The wall of the oogonium consists of three layers, the outer exochite, the middle mesochite and inner endochite (Fig. It consists of compactly arranged parenchyma cells of poly­gonal shape, rarely with intercellular spaces. variations occur in other members of fucales conceptacles bisexual: fuci-js conceptacles unisexual: sargassum turbinaria antheridia : each with 64 antherozoids oogonia with 8 eggs > fuci-js 4 eggs > ascophyllum 2 eggs > pelvetia 1 egg > sargassum, In homothallic or monoecious species the male conceptacle and female conceptacles are produced on same receptacle, but antheridia and oogonia are not produced in same conceptacles. 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