3. GROUP 7
GROUP MEMBERS
BS/2009/243
BS/2009/244
BS/2009/251
BS/2009/252
BS/2009/253
BS/2009/254
BS/2009/256
BS/2009/257
BS/2009/260

4. CONTENT
INTRODUCTION
CLASSIFICATION
STRUCTURAL COMPLEXISITY
REPRODUCTION

5. INTRODUCTION
 680 generas
 4000-6000 species
 Habitats:• In marine
•
•
•
•
In tropical
In warm water
In cooler regions
In fresh water
 Eukaryotic

Nutrition mode
• Autotrophic

6.  Cell organization
Unicellular
Multicellular
-
Cyanidium
- Polysiphonia , Laurencia , Geledium
Geledium
Crystal structure of
Cyanidium
• Thalli
openly branching filaments
Fleshy and foliose erect thalli
Encrusting thalli (calcarious forms )
thallus

7. CLASSIFICATION
KINGDOM- PROTISTA
DIVISION-RHODOPHYTA
CLASS-RHODOPHYCEAE
ORDER
Nemalionales
GENUS
Batrachospermum
ORDER
Cereniales
ORDER
ORDER
ORDER
Gelediales Cryptonemales Gigantinales
GENUS
Polysiphonia
GENUS
Geledium
GENUS
Jania
GENUS
Gracillaria

8. STRUCTURE

9. 
Cell wall
• Rigid
• Inner component
Cellulose
Another polysaccharide
•Outer mucilaginous layer
Sulfated polymer of galactose – agar or carrageenan
•Some deposit calcium carbonate - family –
Corallinaceae (Coralline algae)
Cell structure

10. Absence of flagella and centrioles
Floridean starch as a storage product
Chloroplast
• unstacked plastids in thylakoids
•Pigment
Chlorophyll a,phycoerithrin,phycocyanin
allophycocyanin
presence of the phycobilin or phycoerithin

11. STRUCTURAL COMPLEXISITY OF
Gracillaria

From of thalli
•Often fleshy thalli
•Cylindrical or terete
•Compressed or flattened
•Foliose
 Branching
•Alternate
•Di or trichotomous
•Secund
•Irregular

12.  Constriction of branches
• frequently Gracilaria shows a constriction at the point
where a lateral branch joins a main axis.
Branch apex
•Attenuate
•Rostrate
•Tapering
•Apiculate
•Obtuse
•Blunt

13. Types of spermatangial conceptacles
•Chorda type-superficial
•Textorii type-shallow cavity
•Verrucose type-deep pot like cavity
•Polycavernosa type-compound verrucosa type
Characteristics of cystocarps
•Form
•Basal constriction
•With or without rostum
Anatomy of cystocarp
•Pericarp
•Gonimoblast cells
•Carposporangia
•Absorbing filament
Types of cystocarps

14. Order – Nemalionales
Filamentous or uniaxial multicellular
Stem like thalli often dichotomously branched and
gelatinous in texture
Batrachospermum

15. Order – Cereniales
Slender
Filamentous or uniaxial bush like plants
More complex reproductive structure is characteristic of
this order
Polysiphonia

16. Order- Gelediales
Thalli is cylindrical and wiry or flattened
Usually pinnately branched
Usually pseudo-parenchymatous

17. Order - Cryptonemales
Plants form
Dichotomously branched structure
Growing in tangled
Small clumps
Branches composed of rigid
Cylindrical segments with flexible joints

18. Order- Gigantinales
Crustose to fruticose
Foliose types with thin, broad fronds
fruticose types with flattened
Usually dichotomously branched
Often fleshy thalli
Tissues as in cryptonemiales

19. REPRODUCTION
OF
RHODOPHYTA

20. REPRODUCTION
SEXUAL REPRODUCTION
ASEXUAL REPRODUCTION
ASEXUAL REPRODUCTION
Discharging Spores – monospores
If condition are suitable monospores may attach to a
substrate. By mitosis they produce new seaweeds.

21. Sexual reproduction
Widely among the multicellular red algae.
Alternation of generation.

22. Life Cycle of Polysiphonia
Isomorphic
Gametophytes:•heterothallic
•male gametophytes
•female gametophytes
Spermatia:•unite with the tricohogyne
spermatangia

23. Zygote:•oogamous
•auxillary cell become zygote
•grows in a carposporophyte
Carpospores:•type of mitospores
•produce by carposporophyte
•settle out of water column
•grow in to tetrasporophyte
carcosporangia

24. Tetrasporsphytes:•Isomorphic to gametophyte
•Produce tetrasporangia in which
meiosis takes place
Tetrasporangia
Tetraspores:•produce by meiosis
•shed to the water
•settle out of the water column
•grow up in to gametophytes

25. Sexual Reproduction of
Polysiphonia

26. REPRODUCTON OF Gracillaria
Isomorphic generation
 Gamitophyte

• Male-spermatangia
• Female-carpogonia
• Fertilization structure-cystocarp
 Cystocarp
•Carposporangia-carpospores
Germinate to tetrasporophytes
Formation of tetrasporangium-tetraspores
Germinate to new thalli

27. Sexual Reproduction of
Gracillaria

28. Order-Nemalionales
Mostly haplontic
Usually no auxiliary cells
Nurse cells perform similar
function
Nurse cells and auxiliary cells
form prior to fertilization

29. Sexual Reproduction of
Batrachospermum

30. Order-Gigantinales
Three phase diplohaplontic
A vegetative cell serves as auxiliary cell
Developing prior to fertilization
Secondary pit often elongated in to an
ooblast

31. Order-Gelediales
Three phase diplohaplotic
No auxiliary cells
Gellidium

32. Life Cycle of
Gellidium

33. Order-Cryptonemales
Three phase-Diplohaplontic
Auxiliary cell in special filament
growing from a vegetative cell
Secondary pits elongated to an
ooblast forming prior to fertilization

34. Order-cereniales
Slender
Filamentous or unisexual bush like plants
lacking clear cut differentiation of cortex
and medulla tissues
Simpler anatomy accompanied by more
complex reproductive structure is
characteristic of this order

35. THANK YOU