3. Algae comprise a group of autotrophic,
chlorophyll containing thalloid plants of simplest
type having no true root, stem and leaves.
On the basis of their colours 4 groups were
recognised :-
1. Myxophyceae or Cyanophyceae (Blue green
algae)
2. Chlorophyceae (Green algae)
3. Phaeophyceae (Brown algae)
4. Rhodophyceae (Red algae)
5. Chlorophyll
Chlorophyll a Chlorophyll b Chlorophyll c Chlorophyll d Chlorophyll e
(Primary photosynthetic (Found In Chlorophyceae , (Present in Dinophyceae (Found in many (Found in only
Pigment found in all Charophyceae , Cryptophyceae , Rhodophycean in two genera
Photosynthetic algae) Euglenophyceae ) Chrysophyceae , members ) of Xantho
Bacillariophyceae , phyceae,
Xanthophyceae , Tribmonema ,
Pheaophyceae ) Vaucheria )
Insoluble in water and petroleum ether but soluble in alcohol , benzene and acetone
6. CAROTENOIDS
Group of yellow , orange ,red and brown protective pigments.
Acts as screen to light and pass light energy to chlorophyll.
Soluble in alcohol , acetone , benzene, insoluble in water.
TWO TYPES
CAROTENES :- 6 types ( α,β ,γ ,ε , Flavicine and lycopene )
In most of algae β carotene is present .
In Bacilleriophyceae and some member of cryptophyceae ε carotene is
present.
In Chlorophyceae α carotene is present .
XANTHOPHYLL :-
Fucoxanthin - Present in Chrysophyceae , Bacilleriophyceae ,Phaeophyceae .
Peridinin - Found only in Dinophyceae.
Myxoxanthin and Myxoxanthophyll - Found in cyanophyceae
Taraxanthin - Found in Rhodophyceae
Antheraxanthin - Found in Euglenophyceae .
7. PHYCOBILINS
Water soluble blue or red pigments
Tetrapyrrolic compounds joined to globin protiens
Present in Cyanophyceae, Rhodophyceae,Cryptophyceae
3 types on the basis of absorption spectra
Phycocyanin :- Found in Cyanophyceae
Phycoerythrin :- Found in Rhodophyceae
Allophycocyanin :- Found in Cyanophyceae and Rhodophyceae
8. Polysaccharides in which glucose subunits joined with α -
1,4 linkages are :-
A. Starch ( Chlorophyceae and Charophyceae )
B. Floridean starch ( Rhodophyceae )
C. Myxophycean starch ( Cyanophyceae)
Polysaccharides with β -1,3 linkages are :-
A. Laminarin (Phaeophyceae )
B. Chrysolaminarin (Chrysophyceae & Bacillariophyceae)
C. Paramylon ( Euglinophyceae )
9. 2 types :-
A. Acronematic / Whiplash :- Smooth, do not have hairs on its surface.
B. Pantonematic /tinsel :-have hairs on its surface.
Algal class Flagellar conditions
Chlorophyceae
Xanthophyceae
Chrysophyceae
Bacillariophyceae
Dinophyceae
Cryptoceae
Euglenophyceae
Phaeophyceae
2 or 4 anterior , equal ,acronematic
2 unequal, anterior, 1 acronematic 1
pantonematic
2, 1 acronematic and 1 pantonematic
1 pantonematic, anterior
1 acronematic, 1 band shaped
2 equal, lateral , pantonematic
1 anterior , pantonematic
2 unequal, lateral, 1 acronematic, 1
pantonematic
10. Cyanophyceae - Double membrane bound chloroplast absent.
Thylakoids are free.
Chlorophyceae- Bound by double membrane of chloroplast.
Thylakoids occur in bands of 2-6.
Charophyceae - Bound by double membrane of chloroplast.
Rhodophyceae- Bound by double membrane and thylakoids are free.
Euglenophyceae - Chloroplast envelope is surrounded by one membrane of
chloroplast endoplasmic reticulum (CER).
Xanthophyceae - Chloroplast envelope is surrounded by two membranes
of CER. Thylakoids are grouped in bands of three.
Phaeophyceae - Chloroplast envelope is surrounded by two membranes
of CER. Thylakoids are grouped in bands of three.
Bacillariophyceae- Chloroplast envelope is surrounded by two membranes
of CER.
Chrysophyceae- Chloroplast envelope surrounded by two membrane of
CER.
11. Eye spot are not found in Cyanophyceae, Bacillariophyceae
and Rhodophyceae .
3 types
Eye spot is a part of chloroplast but not associated with
flagella : Chlorophyceae and Chrysophyceae .
Eye spot is a part of chloroplast but associated with flagella :
Cryptophyceae , Xanthophyceae and Pheaophyceae.
Eye spot is independent of chloroplast but adjacent to
flagella : Eugelenophyceae and some Xanthophyceae .
In Dinophyceae eye spot range from collections of lipid
globules containing carotenoids and lacking membrane to
more complex arrays of lipid containing globules.
12. Smith’s system of classification
Fritsch’s system of classification
Classification proposed by Papenfuss
Classification by Prescott
Round’s system of classification
Chapman and Chapman system of classification
13. Classified algae into 7 divisions and divisions into
different classes on the basis of :-
Physiology of vegetative cells.
Morphology of motile reproductive cells .
Reserve foods.
Photosynthetic pigments.
15. Classified algae into 11 classes on the basis of :-
Structure of plant body.
Nature of pigment.
Method of reproduction.
Flagellar condition.
21. Kumar, H.D. (1999): Introductory Phycology Affiliated East West
Press Ltd., New Delhi.
Singh, V.(2013) :A text book of Botany, Rastogi Publications,
Meerut,India.
Vashishta,B.R(1960) : Botany for degree students, Algae, S.Chand
Publishing , New Delhi.