In spirogyra, the sexual reproduction involves a cycle alternation between a haploid vegetative filament gametophyte plant and a diploid zygospore, towards the. Asexual reproduction can occurs by fission, fragmentation, or zoospores. This file is licensed under the creative commons attributionshare alike 4. The sexuality of pteridophytic gametophytes can be classified as follows. The pathogenesis of bacillus anthracis microbewiki. The concept is closely related to those of the life history, development and ontogeny, but differs from them in stressing renewal. Articles and drawings on protoctista, protista, amoeba, paramecium, spirogyra, chlamydomonas, euglena, malaria, resources for biology education by d g mackean. Class 8 tamilnadu board life cycle of spirogyra videos. Cells are similar to those of spirogyra in containing 210 parietal, ribbonlike chloroplasts. May 10, 2017 algae are the simplest multicellular plants. Algal life cycl es include gametic, zygotic, and sporic types. While studying the mode of encysting shown by large forms of the unicellular animal of the genus stentor 500 microns we were able to consistently demonstrate the appearance of dwarf forms, not previously described, which arose from nuclei released from the disrupted larger cells. After fertilization, zygospores are released into the surrounding environment, which remain dormant in harsh conditions.
Eight species of spirogyra such as spirogyra aplospora,spirogyra kanalae form aplanospores during asexual reproduction. It is commonly found in freshwater habitats, and there are more than 400 species of spirogyra in the world. Life processes types of life processes in plants and animals. Bacillus anthracis has the ability to make atp in the presence or absence of oxygen and cannot be seen unless with a microscope.
In what ways does chlaydomonas resemble sperm cells. In biology, a biological life cycle or just life cycle or lifecycle when the biological context is clear is a series of changes in form that an organism undergoes, returning to the starting state. Spirogyra sposnowflake vegetative cells, showing tightly. Pteridophyta characteristics, life cycle, classification. The larger family zygnemataceae, with wellknown genera such as zygnema and spirogyra, includes members that grow as unbranched filaments, which grow longer through normal cell division. However, the chloroplasts are either parallel to the cell axis or, if spiralling, rarely. The life cycle of algae is also described in another term known as life history. However, in some other brown algae the oosphereproducing oogonia and the sperm cells producing antheridia are either together in the same receptaculum e. Algaegeneral characteristics and classification online. General structure of chlorophyta 3 reproduction and life cycle chlorophyta reproduce both sexually and asexually, but usually sexually. Spirogyra structure and asexual reproduction duration. The group is a heterogeneous one in which the members, although superficially similar, show a wide diversity in their life cycle and modes of reproduction.
A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Spirogyra and sirogonium are reported to produce diploid gametes with synapsis of homologous chromosomes before fusion of gametic nuclei. In spirogyra, 3 types of life cycle can be seen vegetative and sexual cycles are most common. In many cases, however, asexual reproduction by cell division, fragmentation of filaments, or mitospores is more common than sexual reproduction. Life cycle of algae is defined as the sequence of different phases, both morphological and cytological, through which an alga completes its cycle. Learn vocabulary, terms, and more with flashcards, games, and other study tools.
Spirogyra is a filamentous algae, commonly found in freshwater ditches and ponds. Similar to the life cycle of seed plants, the pteridophytes also involves the alternation of generations in its life cycle. General characters gametophyticplantbody vegetativestructure. Algae are usually aquatic, either freshwater or marine and some are terresterial. Algae are photosynthetic organisms belonging to the kingdom protista. Eight species of spirogyra such as spirogyra aplospora, spirogyra kanalae form aplanospores during asexual reproduction. Spirogyra is also known as pond silk, as its filaments shine like silk due to the presence of mucilage. During adverse environmental conditons, the cells produces nearly identical gametes. Conjugation refers to the process where gametes are transferred from one individual to another by a connection between the two. In fact, the cylindrical cells assembled in the form of filaments are haploid.
Under suitable light and temperature, the complete life cycle is completed in 56 months. Scoring key with explanation bpyrenoids holds the nucleus in spirogyra. The genus spirogyra comprises more than 300 species and most of them are free floating algae. Figure 2 shows bacillus anthracis in its spore form. Alga is the singular of algae with a changing size from microscopic unicellular microalgae chlorella and diatoms to large massive kelps that are usually a length extending in meters 200 feet and then theres brown alga one of the giant. Reproduction process by which something makes copies of itself. Under suitable light and temperature, the complete lifecycle is completed in 56 months. Stages in scalariform conjugation of spirogyra life cycles, diagram, seeds, medical. A by zoospores the zoospore formation takes place during favourable conditions. This genus is photosynthetic, with long bright grassgreen filaments having spiralshaped chloroplasts. Pdf species identification of the ubiquitous green algae genus spirogyra link based on. They also undergo sexual reproduction via the union of antheridia and oogonium.
Reproductive cycle of pines the amazing lives of plants. The genus spirogyra comprises more than 300 species and most of them are free. Sexual reproduction in paramecium is called conjugation, while asexual reproduction is known as binary fission. Most zygnemids, such as zygnema, spirogyra, and mougeotia, form pond scumsstringy masses of long, unbranched filaments. Transitions of form may involve growth, asexual reproduction, or. The first eukaryotes the kingdom protista was created when biologists began to investigate the diversity. Spirogyrahabitat, structure, reproduction and germination of. Mcq on kingdom fungi mcq on kingdom plantae mcq on kingdom. Spirogyra is a freshwater alga found freely floating on the surface of the stagnant pools, ponds and ditches, etc. Life cycle of a moss mosses te ara encyclopedia of new. The spirogyra cycle in lakes spirogyra starts growth in the spring and appears as green clouds near the lake bottom. Spirogyrahabitat, structure, reproduction and germination. Spirogyra is a green algae belonging to the class chlorophyceae. Green seaweed research will benefit hugely from the development of a model organism.
A slight disturbance in any of the life processes disturbs the entire functioning of. In diatoms, auxospores help in a metabolism b spore formation c reproduction d growth learn more. Spirogyra starts growth in the spring and appears as green. The complete lifecycle of porphyra tenera was obtained in vitro. Chemically defined media or enriched sea water permit good growth of these unialgal not bacteriafree cultures. Bacillus anthracis is a gram positive, endospore forming bacteria. The process occurs thousands of times a day and is dependent on a number of factors for its success, including water temperature, sunlight availability, nutrient content of the water and water ph.
Spirogyra is sometimes called pond scum 2 it is the green, slimy growth of. Choose from 35 different sets of spirogyra flashcards on quizlet. Life cycle of nostoc sphaericum nostocales, cyanoprokaryota in tropical wetlands article pdf available in nova hedwigia 8812. Characteristics of spirogyra algae lifeeasy biology. Algae guide a case study about the life journey of algae. Mesotaeniaceae for example, cylindrocystis, mesotaenium, netrium, and zygnemataceae. The term life cycle signifies the process and events which transpires starting with one. Structure and life cycle of spirogyra botany studies. In many simple organisms, including bacteria and various protists, the.
Oedogonium are filamentous, with rings of cells produced in succession of cell division. The lifecycle of porphyra tenera in vitro the biological. These larger cells had encysted in an unfavorable environment due to evaporation to a dry. Life cycle, in biology, the series of changes that the members of a species undergo as they pass from the beginning of a given developmental stage to the inception of that same developmental stage in a subsequent generation. Multiple choice questions on kingdom protozoa mcq biology. Some mosses have separate male and female plants, whereas others have male and female sex organs on the same plant. I biology i lecture outline 9 kingdom protista references textbook pages 373392, lab manual pages 95115 major characteristics. All the cells are alike and arranged in a single row. It is commonly found in freshwater habitats, and there are more than 400 species of spirogyra in. Introduction unicellular animals of the genus stentor have been the subject of study dating back to the 19 th century 1.
Life cycle, reproduction, and sex life cycle sequence of stages in the growth and development of an organism. Life cycle of spirogyra and germination of zygospore. Pdf induction of sexual reproduction in spirogyra clones does. The same cells that released gametes can release zoospores dp. Hydrodictyon, although quite different in form and growth habit from pediastrum, is similar with regard to its life history. Little is known about the life cycles of most charophytes, but unusual phenomena have been reported in comparatively wellstudied taxa. It is an unbranched, filamentous green algae occurring in the stagnant water so known as pond scum a mucilaginous covering or sheath is present which makes the surface slimy hence known as pond silk.
Life cycle of spirogyra is haploidic where the haploid vegetative filament represents a prolonged gametophyte generation and the brief sporophyte phase is represented by diploid zygospore zygote. Filaments grow loosely attached to hard substrata, on submerged aquatic vegetation, or freefloating in quiescent waters and are typically coated with mucilage. Most euglena have a life cycle consisting of a freeswimming stage and a nonmotile stage. Here, the protoplast of the cell after forming rounded structure develop thin cellulosic walls around themselves and form the aplonospore which are the thin walled,non motile spores that can germinate into new filament. The uniseriate filaments of this genus have cells that range from one to more than 5 times longer than broad.
Following the progression of these dwarfs over several days, allowed us to view their life cycle eventually leading to their own encysting stage. The euglenoid cell reproduces its organelles by mitosis and then splits longitudinally into two daughter cells. Paramecium reproduction takes place by both forms asexual and sexual, out of which the former type is predominant. Spirogyra common names include water silk, mermaids tresses, and blanket weed is a filamentous chlorophyte green algae of the order zygnematales, named for the helical or spiral arrangement of the chloroplasts that is characteristic of the genus. In the genus laminaria these gametophytes, the haploid life forms, appear as small ramified filaments. Named for their beautiful spiral chloroplasts, spirogyras are filamentous algae that consist of thin unbranched chains of cylindrical cells. For the most part its life cycle, chlamydomonas exist as a freeliving haploid cell. Spirogyra is a filamentous charophyte green algae of the order zygnematales, named for the. Spirogyra common names include water silk, mermaids tresses, and blanket weed is a filamentous charophyte green algae of the order zygnematales, named for the helical or spiral arrangement of the chloroplasts that is characteristic of the genus. Chlorophyta are photosynthetic organisms, obtaining starch from photosynthesis.
This gallery includes only the filamentous green algae. Spirogyra, any member of a genus of some 400 species of freefloating green algae found in freshwater environments around the world. Externalfeatures itisacommontypeof watermoss whichgrows onmoist,shady,anddampsoil,onmoistwalls and the crevices of rocks and places where recentfireshavetakenplace. Fusion of two nuclei results in formation of diploid zygospore. Spirogyra, one of the commonest green filamentous algae figure 1. The familiar leafy moss plant is the sexual phase of the moss life cycle. Chlamydomonas species can become so abundant as to colour fresh water green, and one species, c. Go through this article for a brief overview about these algae. Most of them are found in fresh water of tanks, ponds, lakes etc. Class8 tamilnadu board life cycle of spirogyra learnnext offers animated video lessons with neatly explained examples, study material, free ncert solutions, exercises and tests. The euconjugates, which are generally filamentous forms, consist of one order zygnematales.
In this article we will discuss about the asexual and sexual methods of reproduction that occur in the life cycle of chlamydomonas. Coming to spirogyra life cycle, it comprises haploid adult cells. In wet conditions, sperm cells are released from male sex. The outer cell wall has pectin which dissolves continuously, thereby producing the mucilage. The life processes help a body survive with the changes in the environment. However, the pteridophytes differ from mosses and seed plants in that both generations are independent and freeliving.
Spirogyra blooms are also reported from aquaculture pens and littoral habitats in lake huron, often loosely attached to cladophora filaments, which can be dislodged during storm events. Some important examples include the paramecium bursaria and the paramecium. They help to produce energy and maintain homeostasis in the body. The sexual life history is haplontic and isogamous note dl for gamete release and zygote formation. The important characteristics of algae spirogyra are. Both the conchocelis and the thallus phases may be grown out of season. Gerrath, in freshwater algae of north america, 2003. The macroalgae known as oedogonium are unique organisms and can be used to study both asexual and sexual reproduction. In the freeswimming stage, euglena reproduce rapidly by a type of asexual reproduction method known as binary fission. Structure and life cycle of spirogyra spirogyra is one of the commonest and large genus with about 300 species growing as freefloating masses in stagnant or slowly moving waters streams. Algae reproduction, identification and classification. There are more than 400 species of spirogyra in the world. Ncert class 9 science lab manual plant kingdom cbse tuts.
1659 677 15 855 342 1433 1286 1378 1111 646 964 604 63 1357 323 1293 263 853 1282 3 1011 1265 276 963 105 1414 1172 1235 1043 381 772 1240 44