Rhodophyta by sohail hashmi

General account
classification
biochemistry
evolution
economic importance

1. Rhodophyta

2. Presented by: Muhammad Sohail Riaz Presented to: DR Umair Ahmad Awan

3. Table of Contents General account Evolution Classification Bio-chemistry Economic importance

4. General Account Also called as Red Algae All species are multicellular  One of the oldest groups of eukaryotic algae  Also comprises one of the largest phyla of algae Predominately marine about 98% Red algae are commonly found in the depths of oceans Occur in all oceans but few in polar seas

5. Cont ….. Marine form recognize by their bright color Fresh water forms are bluish green color They live attached to rocks by a structure called holdfast 5250 species and 831 genera are known Reproduction is very complex process in these organisms Sexual and A-sexual reproduction is present while vegetative reproduction is very rare

6. Cont …… Cell is typically eukaryotic Their cell wall contain thick polysaccharides Protoplast is surrounded by two layered cell wall Inner consisting of cellulose and outer with pectin material Some red algae’s cell wall contain xylans Reserved food stores as a complex carbohydrates Endoplasmic reticulum, Mitochondria and Dictyosomes are present in rhodophytes

7. Systematics Position Division : Rhodophycophyta Class : Rhodophyceae Sub-class : Florideae Order : Gelidiales Family : Gelidiaceae Genus : Gelidium Specie : Cartilagineum

8. Evolution Evolution According to Schopf , Rhodophyceae is an ancient Fossils of red algae are known from Cambrian According to Klein and Cronquist, Rhodophytes were “probably derived from cyanophytes”, with a cyanidium like alga as a possible link between these two groups Earlier rhodophytes were unicellular, from which evolved the filamentous rhodophytes

9. Cont ….. Cont ….. According to Kohlmeyer , red algae gave rise to higher fungi, through loss of plastids According to Lee, there is no agreement amongst phylogenist whether or not the two major groups are two “Natural groups derived from two separate line of evolution According to Scagel et.al, Conchocelis stage of Bangia and Porphyra represents a link between Bangioideae and Florideae

10. Bio-chemistry Photosynthetic pigments of rhodophyta are chlorophyll a and b Red algae are red due to phycoerythrin Red algae contain sulfated polysaccharide carrageenan in the amorphous section of their cell wall Red algae also produce a specific type of tannin called Phlorotannins , but in lower amount than brown algae do

11. Classification Based on thallus organization and post fertilization changes, Fritsch divide into two classes: Bangioideae Florideae

12. Cont …….. The sub-classes was further divided into six orders: Nemalionales Gelidiales Cryptonemiales Gigartinales Rhodymeniales Ceramiales

13. Cont ……. Smith raised the class rhodophyaceae to the rank of division and named it as rhodophyta V.J Chapman and D.J Chapman placed rhodophyaceae into phylum rhodophyta and divide into sub-classes: Bangiophycidae Florideophycidae Bangiophycidae divided into five orders Florideophycidae divided into seven orders

14. Cont …..

15. Economic Importance Red algae is high in vitamins, minerals and antioxidants that are easily utilized by your body Associated with the production of polysaccharides Agar is delicacy in Japan which is jelly like food Agar provide a polysaccharide gel, which is non-toxic, solid and cannot be digested Agarosa , an alternate polysaccharide sold at great expense

16. Cont ….. Nori used for wrapping sushi, rice cracker, topping on rice Porphyra japonica is eaten in Japan The cultivation of nori is a substantial industry The main benefits of red algae is its ability to promote healthy circulation in your body, regulate your blood sugar levels and lower bad cholesterol levels since it is high in dietary fiber The red algae furnish food for sea animals

17. Cont ….. Calcareous red algae like Lithothamnion , Lithophyllum , Porolithon and Goniolithon play an important role in the formation of coral reefs

18. Thank you