6.Plant kingdom by BNP.pdf
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The document discusses systems of biological classification, including artificial, natural, and phylogenetic classifications, highlighting the limitations of Linnaeus's artificial system. It also covers the characteristics and reproductive methods of algae, emphasizing their ecological importance and various commercial uses. Additionally, it classifies algae into three main groups: chlorophyceae (green), phaeophyceae (brown), and rhodophyceae (red).
6.Plant kingdom by BNP.pdf
- 1. PLANT KINGDOM By Mr. Biswanath prusty
- 2. 1. Artificial System 2. Natural System 3. Phylogenetic System Systems of Biological Classification
- 3. Earliest systems of classification. They were based on vegetative characters or superficial morphological characters such as habit, colour, number and shape of leaves, etc. Linnaeus’s artificial system of classification was based on the androecium structure. 1. Artificial Classification Systems Systems of Biological Classification Carl Linnaeus
- 4. Drawbacks: They separated the closely related species since they were based on a few characteristics. Equal weightage to vegetative & sexual characteristics. This is not acceptable since the vegetative characters are more easily affected by environment. 1. Artificial Classification Systems Systems of Biological Classification Carl Linnaeus
- 5. These are based on natural affinities among organisms. It considers external features and internal features (ultrastructure, anatomy, embryology & phytochemistry). E.g. Classification for flowering plants given by George Bentham & Joseph Dalton Hooker. 2. Natural Classification Systems Systems of Biological Classification
- 6. These are based on evolutionary relationships among the organisms. This assumes that organisms in the same taxa have a common ancestor. 3. Phylogenetic Classification Systems Systems of Biological Classification
- 7. Numerical Taxonomy: It is based on all observable characteristics. It is carried out using computers. Number & codes are assigned to all the characters and the data are processed. Thus hundreds of characters can be equally considered. Cytotaxonomy: It is based on cytological information like chromosome number, structure, behaviour etc. Chemotaxonomy: It uses the chemical constituents of the plant. Other sources to resolve the problems in classification Systems of Biological Classification
- 8. ALGAE
- 9. Simple, thalloid, autotrophic, chlorophyll-bearing and aquatic (fresh water & marine) organisms. They also occur in moist stones, soils & wood. Some occur in association with fungi (lichen) and animals (e.g. on sloth bear). ALGAE Algae Lichen Sloth bear green fur is due to presence of certain algae
- 10. The form and size of algae is highly variable. ◦ Microscopic unicellular forms: E.g. Chlamydomonas. ◦ Colonial forms: E.g. Volvox. ◦ Filamentous forms: E.g. Ulothrix and Spirogyra. ALGAE Chlamydomonas Volvox Ulothrix Spirogyra Spirogyra
- 11. Vegetative reproduction: By fragmentation. Each fragment develops into a thallus. Asexual reproduction: By the production of spores. E.g. zoospores (most common). They are flagellated (motile). They germinate to give rise to new plants. Sexual reproduction: Through fusion of two gametes. Reproduction ALGAE
- 12. Sexual reproduction is many types: Isogamous: Fusion of gametes similar in size. They may be flagellated (e.g. Ulothrix) or non-flagellated (non- motile, e.g. Spirogyra). Anisogamous: Fusion of two gametes dissimilar in size. E.g. Some species of Eudorina. Oogamous: Fusion between one large, non-motile (static) female gamete and a smaller, motile male gamete. E.g. Volvox, Fucus. Reproduction ALGAE
- 13. 1. Through photosynthesis, they fix half of the total CO2 on earth and increase the level of dissolved oxygen. 2. They are primary producers and the basis of the food cycles of all aquatic animals. Benefits of algae ALGAE
- 14. 3. About 70 species of marine algae are used as food. E.g. Porphyra, Laminaria &Sargassum. 4. Agar (from Gelidium & Gracilaria) is used to grow microbes and in ice- creams & jellies. Benefits of algae ALGAE Porphyra Laminaria Sargassum Gelidium Gracilaria Agar agar Agar products
- 15. 5. Some marine brown & red algae produce hydrocolloids (water holding substances). E.g. algin (brown algae) & carrageen (red algae). These are used commercially. 6. Protein-rich unicellular algae like Chlorella & Spirullina are used as food supplements by space travellers. Benefits of algae ALGAE Chlorella Spirullina
- 16. Classes of Algae Chlorophyceae (Green Algae) Phaeophyceae (Brown Algae) Rhodophyceae (Red Algae) Classification ALGAE
- 54. Have a good day Thank you for your attention