1. Algae General Characters. Dr. Thirunahari Uagandhar pptx

Algae General Characters

1. By Dr.Thirunahari Ugandhar Asst Prof of Botany Govt. Degree College Mahabubabad-506101 (T.S.)

2. The term algae (Latin — seaweeds) was first introduced by Linnaeus in 1753, meaning the Hepaticeae . The algae comprise of a large heterogeneous assemblage of plants which are diverse in habitat, size, organisation , physiology, biochemistry, and reproduction. It is an important group of Thallophyta (Gr. Thallos — a sprout; phyton — a plant), the primitive and simplest division of the plant kingdom. The orderly system­atic study of algae is called Phycology ( Gr.phycos — seaweeds; logos — study or discourse ).

3. The algae are chlorophyll-containing primi­tive plants, both prokaryotic and eukaryotic, with wide range of thaifi starting from unicellular to multicellular organisations . Autophytic (which can manufacture their own food) and thalloid plant bodies are also found in Bryophytes . ఆల్గే క్లోరోఫిల్ కలిగిన ప్రాచీన మొక్కలు, ప్రొకార్యోటిక్ మరియు యూకారియోటిక్ రెండూ, విస్తృత శ్రేణి థైఫీలు ఏకకణాల నుండి బహుళ సెల్యులార్ సంస్థల వరకు ప్రారంభమవుతాయి. ఆటోఫిటిక్ (ఇది వారి స్వంత ఆహారాన్ని తయారు చేయగలదు) మరియు థాలాయిడ్ మొక్కల శరీరాలు కూడా బ్రయోఫైట్స్‌లో కనిపిస్తాయి .

4. Definitions of Algae: The definitions of algae as given by some phycologists are: 1 . Fritsch, F. (1935) defined algae as the holophytic organisms (as well as their numerous colourless derivatives) that fail to reach the higher level of differentiation cha­racteristic of the archegoniate plants . 2. Smith, G. M. (1955) defined algae as simple plants with an autotrophic mode of nutrition . ఆల్గే యొక్క నిర్వచనాలు: కొంతమంది ఫైకాలజిస్టులు ఇచ్చిన ఆల్గే యొక్క నిర్వచనాలు: 1. ఫ్రిట్ష్, ఎఫ్. (1935) ఆల్గేను హోలోఫైటిక్ జీవులు (అలాగే వాటి రంగులేని ఉత్పన్నాలు) గా నిర్వచించారు, ఇవి ఆర్కిగోనియేట్ మొక్కల యొక్క అధిక స్థాయి భేదాత్మక లక్షణాన్ని చేరుకోవడంలో విఫలమవుతాయి. 2. స్మిత్, జి. ఎం. (1955) ఆల్గేను ఆటోట్రోఫిక్ మోడ్ ఆఫ్ న్యూట్రిషన్ ఉన్న సాధారణ మొక్కలుగా నిర్వచించారు

5. D ISTINGUISHING FEATURES : They are photoautotrophs They primarily inhabit aquatic habitats The vegetative body does not show any differentiation into various tissue systems They show progressive complexity in reproduction They do not develop embryo after fusion of gamates during sexual reproduction Range in size from microscopic to single celled organisms to large seaweed Many species occur as single cells others as multicellular

6. Algal cells are eucaryotic Study of algae is called phycology Cellwall is thin and rigid Motile algae such as euglena have flexible cell membrane called periplasts Cell walls of many algae are surrounded by a flexible gelatinous outer matrix A discrete nucleus is present Inclusions like starch granules, oil droplets and vacuoles are present Chlorophyll and other pigments are present Chloroplasts may occur one,two or many per cell they may be ribbon like ,bar like ,net like,or as discrete discs

7. Characteristics of Algae: 1. Algae are chlorophyll-bearing autotrophic thalloid plant body. 2. Almost all the algae are aquatic. 3. The plant body may be unicellular to large robust multicellular structure . 4. The multicellular complex thalli lack vascu­lar tissue and also show little differentiation of tissues. 5. The sex organs are generally unicellular but, when multicellular , all cells are fertile and in most cases the entire structure does not have any protection jacket . ఆల్గే క్లోరోఫిల్-బేరింగ్ ఆటోట్రోఫిక్ థాలాయిడ్ ప్లాంట్ బాడీ. 2. దాదాపు అన్ని ఆల్గేలు జలచరాలు. 3. మొక్కల శరీరం పెద్ద బలమైన బహుళ సెల్యులార్ నిర్మాణానికి ఏకకణంగా ఉండవచ్చు. 4. బహుళ సెల్యులార్ కాంప్లెక్స్ థాలికి వాస్కులర్ కణజాలం లేదు మరియు కణజాలాల యొక్క చిన్న భేదాన్ని కూడా చూపిస్తుంది. 5 . లైంగిక అవయవాలు సాధారణంగా ఏకకణంగా ఉంటాయి, అయితే, బహుళ సెల్యులార్ అయినప్పుడు, అన్ని కణాలు సారవంతమైనవి మరియు చాలా సందర్భాలలో మొత్తం నిర్మాణానికి రక్షణ జాకెట్ ఉండదు .

8. 6.The zygote undergoes further development either by mitosis or meiosis, but not through embryo formation. 7. Plants having distinct alternation of genera­tions. Both gametophyte and sporophyte generations — when present in the life cycle are independent . Occurrence of Algae: The algae are ubiquitous (present every­where) in distribution, i.e., they are found in fresh water as well as marine water, on soil, on rock, as epiphytes or parasites on plants and animals, in hot springs, in desert, on permanent snow-fields etc. But they mainly dwell in aquatic environments.

9. G ENERAL CHARACTERISTICS : Thallus organisation Cell structure Algal flagella Algal pigments Algal nutrition Food reserves Reproduction

10. 1) T HALLUS ORGANISATION : a)Unicellular algae : single cells, motile with flagellate (like Chlamydomonas and Euglena ) or nonmotile (like Diatoms ). Occor in all groups except carophycae of phylum chlorophyta and pheophyta . Rhizopodial Flagellate Spiral fillamentous Nonmotile

11. b)Colonial algae: Motile or non motile algae may form a colony by aggregation of the products of cell division with in a mucillagenous mass.

12. Coenobial : The colony is formed with a definite shape, size and arrangement of cells. Ex: volvox Palmelloid : Irregular arrangement of cells varying in number ,shape and size. Ex: Chlamydomonas , Tetraspora Dendroid: Looks like microscopic tree due to union of mucilagenous threads present at base of each cell. Ex: Chrysodendron Rhizopodial colony: Cells are united through rhizopodia Ex: Chrysidiastrum

13. c)Filaments algae: Daughter cells remain attached after cell division and form a cell chain Adjacent cells share cell wall (distinguish them from linear colonies!) May be unbranched (uniseriate such as Zygnema and Ulthrix ) or branched (regular mutiseriate such as Cladophora or unreguler mutiseriate such as Pithophora ). 10 Pit hopho ra Cladophora

14. Coenocytic or siphonaceaous: one large, multinucleate cell without cross walls such as Vaucheria Parenchymatous: mostly macro-scopic algae with t i s s ue of u n d i f fe r e n ti a ted c e l ls and growth originating from a meristem with cell division in three dimensions such as Ulva

15. 2)C ELL STRUCTURE Eukaryotic characterised by presence of well organised nucleus and membrane bound organelles like plastids ,mitochondria and Golgi bodies An intermediate form called mesokaryotic occurs in Dianophyceae which shows both eukaryotic (nucleus with nuclear membrane & chromosomes) and prokaryotic characters( basic proteins are absent) Some do not has true cell wall Ex: euglena, gymnodinium & possess a membrane called pellicle around cytoplasm Motile flagella possess a pigmented spot known as eye-spot or stigma (swimming) Cell wall is with mixed carbohydrates and substances like alginic acid , fucoidin , fucin & hemicelluloses present Mitochondria, Golgi complex , Endoplasmic reticulum present.

16. 3)A LGAL FLAGELLA Found in all algae except Rhotophyceae The main function is motility They are of 2 types Whiplash or acronematic- possess smooth surface Tinsel or pleuronematic- covered by fine filamentous appendages called as mastigonemes or flimmers Tinsel is divided into 3 types Pantonematic -mastigonemes arranged in two opposite rows or radially Pantocronematic- Pantonematic flagellum with a terminal fibril Stichonematic - mastigonemes develop only on one side of the flagellum

17. 4)A LGAL PIGMENTS -Distinct chlorplast, nuclear region and complex organelles. - Thylakoids are grouped into grana p y r e n o ids are c e nters of c a rbon dioxide fixat i on wi t hin the c h loroplasts of alga e . P y renoids are not m e mb r an e -bound organ e l l e s , but s p e c ialized areas of the levels pla s tid that c o ntain high of ri b ulo s e -1,5- bi s pho s phate car b oxyla s e / oxygenase granum with a Stack of th y lakoids p y renoid

18. The pigments are within membrane bound organelles called plastids May be leucoplasts (colourless plastids) or chromoplasts (coloured plastids) Chromoplasts- contain chlorophyll a and b Chromatophores - contain only chlorophyll a Types - Chlorophylls(5), xanthophylls(20), carotenes(5) and phycobillins (7) Chlorophyll a present in all Xanthophylls(yellow/brown) present in chlorophyceae and pheophyceae B carotene present in most algae Phycobillins are water soluble red(phycoerythrin) and blue(phycocyanin) confined to rhodophyceae

19. 5)ALGAL NUTRITION : Photo autotrophic and synthesis their own food from carbondioxide and water Aquatic forms obtain carbon dioxide and water by diffusion and osmosis Aerials obtain water from damp substratum and carbon dioxide from air They also synthesis oil and protiens from carbohydrates

20. 6)F OOD RESERVES Food materials accumulated as polysaccharides True starch -seen in two algal divisions chlorophyta and charophyta Floridean starch- found in rhodophyta Laminarin - found in brown algae Paramylo n - found in euglenoids Leucosin -peculiar to xanthophyta , bacillariophyta & chrysophyta Fats occur as reserved food in appreciable amounts in the cells of xanthophyta , bacillariophyta & chrysophyta

21. 7)R EPRODUCTION IN ALGAE MOST REPRODUCE BOTH SEXUALLY AND ASEXUALLY Most sexual reproduction is triggered by environmental stress Asexual Reproduction Mitosis Sexual Reproduction Meiosis Zoospores Plus and minus gametes Zygospore

22. R EPRODUCTION IN ALGAE V eg e tati v e Cell divisions/Fragmentation =part of the filament bre a ks off from the r e st and forms a new one. Asexual Reproduction . Sexual- Ga m et e s

23. ISOGAMY - Both gametes have flagella and similar in size and morphology. ANISOGAMY -Gametes have flagella but are dissimilar in shape and size. One gamete is distinctly smaller than the other one. OOGAMY -gamete with flagella (sperm) fuses with a larger, non flagellated gamete (egg).

24. Monecious : both gametes produced by the same individual Diecious : male and female gametes are produced by different individuals Homothallic : gametes from one individual can fuse (self-fertile) Heterothallic gametes from one individual cannot fuse (self-sterile) Conjugation: a special type of reproduction. The entire cell serve as a gametes and the cell content are transported passively between two cells taking part in sexual reproduction

25. R EPRODUCTION IN M ULTICELLULAR A LGAE Oedogonium reproduction Antheridium -release flagellated sperm that swim to the oogonium Oogonium - houses the zygote which is a diploid spore The spore undergoes meiosis and produces 4 haploid zoospores. One of the four cells becomes a root like holdfast the others divide and become a new filament. o o g o n i um

26. holdfa s t

27. CLASSIFICATION OF ALGAE BASED ON SEVEN MAJOR DIVISIONS Nature and properties of pigments Chemistry of reserve food products Morphology of flagella Morphology of cells and thalli Life history reproductive structures and methods of reproduction Food-storage substance Cell wall composition

28. A famous botanist F.E. Fritsch (1935) classified algae into following 11 classes, based on pigmentation, reserve food material, flagellation and reproduction. Class 1. Chlorophyceae (= Isokontae ): Important genera are: Chlamydomonas , Volvox , Chlorella, Ulothrix , and Spirogyra. Class 2. Xanthophyceae (= Heterokontae ): Important genera are: Microspora , Vaucheria , Protosiphon . Class 3. Chrysophyceae : Example:Chrysosphaera . Class 4. Bacillariophyceae (= diatoms):Examples: Pinularia , Navicula , Fragilaria . Class 5. Cryptophyceae:Example:Cryptomonas . Class 6. Dinophyceae:Example:Peridinium . Class 7. Chloromonadineae:Example:Vacuolaria . Class 8. Eugleninae:Example:Euglena . Class 9. Phaeophyceae:Examples:Fucus , Sargassum . Class 10. Rhodophyceae:Examples : Polysiphonia and Batrachospermum.Class 11. Myxophyceae (= Cyanophyceae ): Examples: Nostoc , Oscillatoria , Anahaena , Lyngbya , Plectonema .  

29. P HYLUM R HODOPHYCOPHYTA  4000 species of RED Algae Most are marine Smaller than brown algae and are often found at a depth of 200 meters. Contain chlorophyll a and rarely d as well as phycobilins which are important in absorbing light that can penetrate deep into the water Have cells coated in carageenan which is used in cosmetics, gelatin capsules and some cheeses Red algae GELIDIUM from which AGAR is made

30. R ED A LGAE Porphyra - nori use to wrap uncooked fish & other food items Smithora naiadum - a epiphyte on eel and surf grass Pikea robusta Red Algae

31. P HYLUM X ANTHOPHYCOPHYTA Yellow Green Algae Xanthophytes walls with cellulose and pectin Chlorophyll a,c and rarely e are present Cellular storage product is chrysolaminarin Flagella unequal in length Asexual reproduction by cell division and fragmentation Vaucheria i s a well known member of this division

32. VAUCHER I A

33. P HYLUM C HRYSOPHYCOPHYTA Golden Algae  predominately flagellates some are amoeboid  Chlorophyll a and c present  Reserve food as chrysolaminarin and their frequent incorporation of silica  Characteristic color due to masking of their chlorophyl by brown pigments  Reproduction is commonly asexual but at times isogamous

34. GOLDEN ALGAE

35. P HYLUM P HAEOPHYCOPHYTA 1500 species of Brown algae Mostly marine and include seaweed All are multicellular and large (often reaching lengths of 147 feet) Individual alga may grow to a length of 100m with a holdfast, stipe and blade Chlorophyll a and c present Used in cosmetics and most ice creams Many of them have holdfasts and air bladders which give them buoyancy

36. Fucus sp. Nereocystis luekeana

37. P HYLUM B ACILLARIOPHYCOPHYTA The Diatoms Diatoms provide abundant food supply for aquatic animals Chlorophyll a and c present Shells of diatoms are called frustules Deposits of these shells from centuries of growth are called diatomite or diatomaceous earth

38. DI A T OMS

39. P HYLUM E UGLENOPHYCOPHYTA Unicellular and motile by means of flagella Chl a & b present 1000 species of Euglenoids Have both plantlike and animal-like characteristics Euglena cell with contractile vacoules and fibrils Carry out photosynthesis in chloroplast and is facultatively autotrophic Reproduction by longitudinal binary fission Dormant cysts are formed

40. EUGL E NA

41. P HYLUM C HLOROPHYCOPHYTA Green algae 7000 diverse species green algae contain one chloroplast per cell which contain pyrenoids Both green algae and land plants have chlorophyll a and b as well as carotenoids and store food as starch Both have walls made of cellulose Reproduction by asexual methods or isogamous and heterogamous sexual means

42. P HYLUM C RYPTOPHYCOPHYTA Cryptomonads are biflagellate organisms Cells are slipper shaped and flattened occur singly Some with cellulose wall others naked There are 1 or 2 plastids with or without pyrenoids Reproduction by longitudinal cell division or by zoospores or cysts

43. CRYPTOMONAS

44. P HYLUM P YRROPHYCOPHYTA  Flagella are inserted in the girdle and arranged with one encircling the cell and other trailing  Many are covered only by plasmalemma and in some there is a wall made of cellulose  Some have a series of cellulose plates with in plasmalemma termed thecal plates  Dianoflagellates a diverse group of biflagellated uni cellular organisms present

45. DIANO FLAGELLATES

46. Food for humans Food for invertebrates and fishes in mariculture Animal feed Soil fertilizers and conditioners in agriculture Treatment of waste water Diatomaceous earth (= diatoms) Chalk deposits Phycocolloids (agar, carrageenan from red algae; alginates from brown algae) Drugs Model system for research Phycobiliproteins for fluorescence microscopy Beneficial Aspects of Algae

47. ROLE OF ALGAE TO DETECT ENVIRONMENT POLLUTION Indicator of pollution - algae blooms can occur when too much nitrogen and phosphorus enter a waterway. Algae are ideally suited for water quality assessment because they have rapid reproduction rates and very short life cycles, making them valuable indicators of short-term impacts.

48. Algae can be used to treat both municipal and industrial wastewater. Algae play a major role in aerobic treatment of waste in the secondary treatment process. Algae - based municipal wastewater treatment systems are mainly used for nutrient removal (removal of nitrogen and phosphorous). Algae have the ability to accumulate the heavy metals and thereby remove toxic compounds from the wastewater. In some cases, algae also play a role in the removal of pathogens in the tertiary treatment stage. ALGAE USAGE IN SEWAGE TREATING PLANTS

49. ALGAE IN FILTER PLANTS An algae scrubber filters water by moving water rapidly over a rough, highly illuminated surface, which causes algae to start growing in large amounts. As the algae grow, they consume nutrients such as inorganic nitrate , inorganic phosphate , nitrite , ammonia , and ammonium from the water.

50. ALGAE ROLE IN TREATING HEALTH PROBLEMS Ulva Can be used to treat goiter; reduce fever, ease pain, induce urination Codium Can be used to treat urinary diseases, treat edema, Sargassum Can be used to treat cervical lymphadenitis, edema; Porphyra Can be used to treat goiter, bronchitis, tonsillitis and cough Gelidium Laxative; can be used to treat tracheitis, gastric diseases and hemorrhoids; can be used to extract agarinishes inflammation; reduces fever;

51. HARMFUL EFFECTS OF ALGAE Several species are parasitic on higher plants Green algae cephaleuros attacks leaves of tea,coffee,pepper causing considerable damage Some algae live in the roots and fleshy parts of higher plants but not harmed Acrylicacid is produced by a unicellular algae in plankton act as extracellular inhibitors its shown by chemical analysis Some planktonic algae produce toxins which are lethal to fish and other animals these toxins are extracellular liberated from algae by bacterial decomposition of algal blooms