Vegetative structure in algae

Vegetative structure in algae :-

Algae are unicellular or multicelluler .

A.      Unicelluler :-

These are of following two types :

a.       Motile : 

In these algae movement take place by flagella . e.g Chlamydomonas .variation is found in number & type of flagella

b.      In Cholorophyceae flagella are equal , number may be two or multiple of two

c.       In Dinophyceae & Xanthophyceae unequal flagella . in former they emerge in different planes & in latter in the same plane

d.      In Euglenophyceae , single flagella at the anterior end.

B.      Multicelluler :-

These are of following types

1.)    Colonial :-

 these are motile algae, having definite surface of cels e.g, Volvox On the basis of morphology these are of following types

a.)    Coenobial :-

A colony with definite shape ,size & arrangement of cells is known as  Coenobium may be motile or non motile

b.)    Palmelloid :- Indefinite number of cells , shape and size surrounded by a viscous mucilaginous substances

c.)     Dendroid :- cells of these forms produce mucilagenoud substances and are folded like a branch

d.)    Rhizopodial :- Cells are united through rhizopodia

2.)    Filamentaous :-

 These are following types :-

i.)                  Unbranched filaments :- Such filament may be

a.)    Free floating :- Spirogyra

b.)    Attached to substratum :- Ulothrix

c.)     Form colony :- Nostoc

ii.)                 Branched filaments :- Simple branched  filaments

a.       Heterotrichous :- Thallus differentiated in prostate & erect system e.g Ectocarpus

b.)    Pseudoparenchymatus :- These algae are characterized by uniaxial filament

c.)     Siphonaceous :- These algae consist multinucleate tube like- cells having no septa e.g Vaucheria

d.)    Parenchymatous forms :- In these algae , cells division take place on different sides with the result that they became parenchymatous , having various shape such as flat, tubular or complex. The growth in such form may be intercalary , trichothallic