Algae bsc 1
- 1. ALGAE General Characters Kamaljit Sidhu Associate professor Department of Botany KCW , Civil lines Ludhiana
- 2. General Characters • Phycology-The branch of science which deals with the study of algae • The word Phycology is derived from two words Phykos- Sea weeds and logos-discourse • Phycologist- A Scientist who studies different aspects of algae • Algae-It is a group of most primitive organisms with simple thalloid plant body. • They are autotrophic,o2 evolving green plants • 90% of the oxygen comes from these simple plants • They can be unicellular or multicellular • They show wide variation in their morphology , pigments and other metabolic products • They bear unicellular or multicellular sex organs • They differ in their life histories as well
- 3. Distribution and Habitat • Includes 30,000 species distributed world-wide • They are found growing in a wide variety of habitats • They are ubiquitous and cosmopolitan • Predominantly aquatic , could be terrestrial • Depending upon habitat divided into 3 categories • Aquatic habitat • Terrestrial habitat • Special habitat
- 4. Habitat
- 5. Habitat • Aquatic habitat-They occur in fresh water aquatic habitats and in marine habitat they are grouped as • Phyto planktons-Plants growing and covering the surface of water body , move on the mercy of the water currents , color of the water changes due to the colour of the of water blooms example Chlorella, volvox, Chlamydomonas • Benthos-All the bottom dwelling organisms both the plants and animals , Algae growing attached to the bottom of the water reservoir are called benthophytes , forms growing at the bottom of the soil- epipellic, those which are attached to the rocks and stones- epilithic
- 7. Terrestrial Algae • Algae grow in the moist and well aerated soil-Edaphophytes • They grow on the surface of the soil-Saprophytes-Vaucheria • Some can grow below the surface of the soil-Cryptophytes-Oscillatoria Vaucheria Oscillatoria
- 8. Special Habitats • Thermal Algae-They grow in hot water springs with a temperature ranging from70-85°C,Example-Phormidium • Cryophytes-Algae growing in the polar regions on ice and Snow-Chlamydomonas • Epiphytes-Algae growing on the surface of other plant parts Oedogonium • Surface of the Angiosperms leaves-Epiphyllophytes • On the barks of Angiosperms-Epiphloeophytes • Endophytes-Algae grow within the tissues of the other plants-Anabaena growing inside Azolla • Epizoophytes-Algae growing on the body of other animals-Cladophora on the snails • Endozoophytes-Algae growing inside the body of the animals-Chlorella within the tissues of Hydra
- 9. Special Habitats Thermal Algae- Phormidium Cryophytes-Chlamydomonas Epiphytes-Oedogonium Endophytes-Nostoc in Anthoceros
- 10. Special Habitats Epizoophytic Algae Endozoophytic Algae
- 11. Special Habitats • Symbiotic Algae- Algae growing in association with the plants in which both are benefitted from each other like Nostoc , Anabaena, Lichens • Parasitic Algae-Algae growing as parasites on other plants- Cephaleuros Symbiotic Algae-Lichens Parasitic Algae-Cephaleuros
- 12. Range of Thallus Structure
- 13. Range of Thallus Structure • Unicellular thallus- Single celled organism-Chlamydomonas • Multicellular thallus- Organisms made of large no of cells-Volvox • Palmelloid form- Palm shaped thallus-Tetraspora • Coenobial form- A colony having fixed no of cells-Volvox • Dendroid form- A tree shaped thallus-Ecballocystis • Siphonaceous form- Siphon shaped thallusVaucheria • Filamentous form- Cylindrical , elongated thallus- Oedogonium • Foliaceous form-leaf shaped thallus - Sargassum
- 14. Structure of A Typical Eukaryotic Cell Typical Algal Cell
- 17. Pigments in Algae • Types of pigments in algae-3 types • Chlorophylls • Carotenoids • Phycobilins • Chlorophylls-5 types-chla chlb chlc chld chle -chla widely distributed in all the algae • Carotenoids-2 types-carotenes and xanthophylls • Phycobilins-Acessory pigments-3 types-phycocyanin , phycoethyrin and allophycocyanin
- 21. Asexual Reproduction • Asexual reproduction takes by formation of spores which are haploid and formed in special cells-sporangium • Different types of spores formed are- • Autospore • Hypnospore • Endospore • Exospore • Nannocytes • Monospore • Akinete
- 22. Types of Asexual reproduction In Algae
- 23. Sexual Reproduction • Sexual Reproduction in Algae- The sexual reproduction takes place by formation of gametes • The gametes are of (+) and(-) strain • The sexual reproduction is of three types • Isogamy • Anisogamy • Oogamy • Isogamy-When the fusing gametes are of the same shape size and morphology • Anisogamy-When the fusing gametes are of different shape size and morphology • Oogamy-When the male gamete is motile and the female gamete is non motile ,male gamete swims and reaches the female gamete