CLASSIPICATIQN QP ALGAE

Structure
Introduction
Objectives
Criteria for Classification of Algae
Prokaryotic Algae
Division Cyanophyta (Uluc-grcen :llpac)
Eukaryotic Algae
Division Chlor~phyti~ (Grcen i ~ l g i ~ ~ )
Division Phaeophyta (Brow11algac)
Division Rhodophyta (Red algae)
Division Xanthophytn (yellow-green algae)
Division Chrysophyta (Golden-brown algae)
Division Euglcnophyta (Euglenoids)
Division Diaophyta (I)i~lotlagcllatcs)
Divisio~~Cryptophyta (Crypton~onad)
Division Bacillariophyta (Diatoms)
Systematic Position of Some Genera
Summary
Terminal Questions
Answers

5.1 INTRODUCTION
From the previous two units it is evident that algae show a great diversity in structure
and.reproduction. In this unit you will learn classification of this diverse group.
Classification means gro~lpirigof organisms according to the similarity in their
characters. It is not far fetched but true that organisms showing similar morphology,
life cycle, physiology and biochemistry are genetically related from the evolutionary
point of view (pliylogenetically related) and one is justified in grouping them together.

'rile position of algae as a group among the other groups of organisms has been
discusscd already in the previous Block IA(Unit 2, Page 3 1). It was indicated that
algae could be classified according to their common characters into 8 divisions of
Kingdom Protista (Unit 1, p 18). The relationship among different groups was also
discussed. You may recall that blue-green algae have been grouped as Division
Cyanobacteria, and clubbed with bacteria under-the Kingdom Monera.

In this unit you are introduced to the characteristics of different divisions of algae.
Objectives
After studying this unit you should be able to:

list the vario~lscriteria used for the classification of algae.

explain why algae are classified as protists instead of plants,
list the various divisions of algae and describe the characteristics of each,
classify the genera of algae studied in Unit 3 into division, order and family and
give colnmon examples of algae from each division.

Study Guide
In this unit we have given several exaniples of algae for each divisioh but you arc
expected to remember at least three from each division.

5.2 CRITERIA FOR CLASSIFICATION OF' ALGAE

'I'lie criteria used by phycologists are quite varied. Generally a number of characters
arc used together ranging from external morphology, ultrastructure, chromosome
num3er and their niorphology, pigment composition, nature of cellular storage
 products, enzymes, isoenzy~iies,DNA homology, arid DNA banding etc. As new
techniques are developed they are used to decide more precisely the relatedness (or
absence of it) of organisms which seem otherwise related to each other.

Given below are the salient characters of each of the divisions of the algae. It is to
, be noted that each division is again divided into orders, families, genera and species.
In section 5.5 you will find the classification of all the algae which are included in
your study. Please note that they represent certain divisions, orders, and families
only. Because of the restriction of time representatives of other divisions are not
included in your course, not because they are any less important in the biological
world.

Prokaryotic - Cyanophyta
/ Algae
Algae Chlorophyta

f
\ Phaeophyta
Rhodophyta
Eukaryotic Xanthophyta
AIgae Chrysophyta
EugIenophyta
Dinophyta
Bacillariophyta

5.3 PROKARYOTIC ALGAE

5.3.1 Division CYANOPHYTA (Cyanobacteria or Blue-green
algae)
Prokaryotic algae are placed in Division Cyanophyta. Algae of this division may be
unicellular, colonial, and filamentous, with or wifhout branches, branching may be
'true' or 'false' type. Most forms are embedded in mucilaginous or gelatinous
sheaths.

The composition of cell wall is similar to bacterial cell wall. It is, made up of
distinctive mucopeptides and muramic acid.

The u l t r a s t r u c t m e cell shows no organised nucleus, mitochondria or

chloroplasts, Phetosynthetic lamellae and ribosomes of 70s type are present in the
cytoplasin of the cells. Sorne filamentous forms possess specialised cells termed as
'heterocysts' (ref. to Fig. 3.2), which are involved in nitrogen fixation.

The main photosynthetic pigments are chloropl@ll a and phycobilins - (phycocyanin

and phycoerythrin). A number of carotenoids including pcarotene are also present,
some of which are specific to the division.

Carbon is reserved in the cells as glycogen granules and nitrogen as cyanophyceah

granules. Other granules like polyphosphate granules, some enzyme aggregates like
carboxysomes may also be present.

Reproduction occuis by simple cell division. No motile cells are found in

cyanobacteria and they do not have sexual method of reproduction. Thick walled
cells called 'akinetes' or spores are present in some forms for perennation and
asexual reproduction.

Cynobacteria are distributed all over the earth in diverse habitats, fresh water lakes,
ponds, rivers, arctic, antarctic areas, hot water springs, brine salt pans, desert soils,
subaerial surfaces like tree trunks, building terraces and rock surfaces.

Examples: Anacystis, Microcystis, Nostoc, Anabaena, Oscillatoria, Spirulina,

Calothrix, Tolypo thrrjc,Gleotrichia,Lyngbya, Scytonenia, and Stigonema.
m-
Anacystis

Nostoc Anabaena

Fig. 5.1 :Some examples of blue-green algae.

 Tolypothrix

Fig. 5.2 : 'rllall~lsstructure in blue-grccs rlgre.

5.4 EUKARYOTIC ALGAE

- - - - - - - -- - - - - -- - - -

As you have learnt earlier, that Kingdom Protista includes eight divisions of algae.
Some phycologists make nine divisions treating Bacillariophyta separate from
Chrysophyta. You maxnote that we have also taken it as a separate division. In the
following account they are described in detail below.
5.4.1 Division CHLOROPHYTA (Green algae)
This includes unicellular to multicellular forms of green algae. The ~nulticellular
for~iismay be in the form of filamentous, branched or unbranched, thalloid, tubular
or sheet like arrangement of cells. Some of the green algae are colonial in form. The
cell structure is eukaryotic type as in higher plants with membrane bound organelles-
nucleus, plastids, mitochondria, and cytoplas~nicribosomes of 80s type.

The cell wall is generally made up of cellulose. Sometimes the cells are also covered
with chitin.

The principal photosynthetic pigments are chlorophyll a and b, carotenes and

xanthophylls located in the thylakoids.
 Classification o f Algac

Chlorella

Chlamydomonas

Trentepohlia
\

Coleochaete
Cladophora

Fig. 5.3 :Some members of Division Chlorophyta.

Algae

Fig. 5.4 :A) Several isolated tllrllus ofAcrt~ib~~lnrio,

com~nonlytalled nlern~uid'swineglass, and B)
Cnulrrprc, u coenocytic green algae (courtesy of P. Deyanand~n).

The storage pioducts of the cell are mcktly'starch, but in some algae lipids.

Reproduction occurs by asexual and sexual methods. Asexual reproduction is by

biflagellate or quadri-flagellate zoospores whereas gametes (sexual reproduction) are
biflagellate. The flagella are anterior and of whiplasll type. Sexual reproduction
includes isogamy, anisoganiy, and oogamy.

Green algae are distributed in fresh water and marine habitats; some may be
subaerial on wet soil or bark of trees.

Examples: Chlorella, Chlamydomonas, Pediastrztm, Spirogyra, Cladophara,

Acetabularia, Trentephohlia,Micrasterias and Cuulerpu.
 C'I:~ssilicationof Algae

5.4.2 Division PHAEQPHYTA (Brown algae)

Structurally they are most complex in morphology. They range from simple
branched filaments to massive bodies.

Cell wall co~npositionis complex. Besides cellulose, it may contain algin, fucoidin

Principal photosynthetic pigments are chlorophyll a and c and tarotenoids.

Fucoxanthin (brown in colour) is present in large amount that gives alga brown
colour by masking the green colour of chloropl~yll.

I~liotosyntheticstorage product is mannitol, some times laminarin. Rarely, lipid

droplets may be found in the cells.

Sexual reproduction ranges from isogatny to oogamy. The motile swarmers have
two unequal laterally inserted flagella, one of the flagella is larger and anterior and
the other is smaller and posterior.

Most of the brown algae are seaweed, very large in size, comnionly known as kelps.
They are the main source of iodine, agar and related products.

Examples: EC/OCLI~IJ~IS, FIICZI.~,

I!,LII??~MNI.~LI,5'argu.s.~11111.
I)i('lj'olu, Alclria, A.luwocys~is,
i\'ereocy,stis and Putlit lei.
I

Algae

Dictyota

!I Padina

Fig. 5.6 :Some common brow11-algae.

 Classification of Algae

Macrocystis

Nereocystis

Fig. 5.7 : A) Macrocystis, B) Photograph of Nereocystis (Courtesy of P. Dayanandan).

 5.4.3 Division RHODOPHYTA (Red algae)
Most forms are ~nulticellularand highly branched, a few are thalloid and one alga
Coralline algae are a group o f Porphj)ridium is unicellular. The body may be covered with c a l c i ~ ~carbonate
~n
rcd algae that secrete calcium
carbonate around llieir cells
incrustations.
and form slift'tlialli .Corallicie
algae are important builders o f Besides cellulose thcir cell wall contains pectin, polysulphate, esters and large
coral rcefs in tropical water. a~nountof polysaccliarides on the outside of their surface. These polysaccharides are
contrary to the helieve that
coral animals alone make up
the source of agar and carageenans. Certain red algae for example coralline algae
coral rcefs. secrete calcium carbonate around their cells and form1 stiff thalli.

Porphyra

Corallina

Fig. 5.8 : S o ~ i coninion

~c llcd alg:~c.
The maiil photosynthetic pigments are chlorophyll a, d a n d phycoerytlirin. Some red
algae contain pliycocyanin also. The algae appear red or pink in colour because of
large amounts of phycoerytlirin.

The food reserve in the cells is flor-idian starch.

No motile cells are found at any stage of reproduction. Sexual reproduction is

advanced oogamous type. Male gametes - sper~natiaare passively transported by
water movemelits to tlie tip of trichogyne of the female carpogonium. After
fertilisation, special developmental changes occur, that are not found in any other
division of the algae.

Most of tlie red algae are marine in habitat. A few are found in fresh water lakes,
rivers, streams and ponds. Some are epiphytic or parasitic in nature.

Example: Porpl~yridiurn(z~nicellz~lar),
Porpl~yra,Poly.~iphonicr,Grucilariu,
Gelidiunj, and Corallina.
5.4.4 Division XANTHOPHYTA (Yellow-green algae)
Some forms are unicellular and motile while others are filamentous, with
multinucleate cells. .

Photosylithetic pigments are chlorophyll a, c, p-carotene which is present in large

amount, and xanthophylls giving the cells greenish-yellow colour.

Food reserves include lipid and chrysolaminarin (P-1,3.- linked poly~nerof glucose,
also known as leucosin).

Cell wall frequently consists of two overlapping halves, containing pectin, silica and
small amount of cellulose.

Sexual reproduction is rare. The motile cells have two unequal flagella present on
the anterior end; one is tinsel and tlic other whiplash type.

Yellow-green algae are widely distributed in aquatic, fresh water habitats. Some
are sub-aerial and a few are marine in distribution.

Examples: l~aucheria,Botvydium.

Botrydium

Fig. 5.9 :Two nrcrnbcrs of ycllow-green nlgac.

SAQ 5.1
a) List the criteria for classification of algae.

b) In the following statements fill in the blank spscks with appropriate words.
i) In cyanobacteria carbon in reserved as .............................

ii) The colour of red algae is due to ..............................

iii) The storage material in the algae of Divison Phaeophyta is .............,

iv) Sexual reproduction in Xanthophyta is .......................

c) Whicli one of the following divisions of algae does not have motile cells?
i) Cyanophyta
ii) Rhodophyta
iii) ChIorophyta
iv) Phaeophyta
- -

5.4.5 Division CHRYSOPHYTA (Golden brown algae)

Mostly unicellular or colonial, fila~nentousforms are rare.

Motile cells have two equal or unequal flagella present on the anterior end. The
longer one has stiff hairs and the shorter is smooth. The cell wall is made of pectin
and silica or scales of carbonate. The chloroplasts are deeply lobed.

Chromulina '1

Fig. 5.10 : Sonlc ~ n c n ~ b c of

r s Cllrysophytr.
 Classification of Algae
I'rincipal pigments are chlorophyll a, c, and carotenoids like @-carotene,fucoxanthin,
diatoxanthin and neofucoxanthin.

Storage products are mostly oil droplets, and true starch is absent but glucan granules
or leucosin are present.

Sexual reproduction is rare. Most colnlnon features are the formation of resting
cysts, resting spore (statospores), with silica walls.The cysts are formed as a result of
asexual or sexual reproduction.

Golden-brown algae are distributed in marine and fresh water habitats, and in fast
flowing mountain streams. Marine coccolitl~ophoridesare responsible for the
fornlation of chalk beds on the bottom of the sea.

Exarnplest Synzrru, C'hrom~~linrr.

Ochro~ilonos,MaNomo17u.s,U I . I Dinoblyo~i
~

5.4.6 Division EUGLENOPHYTA (Euglenoids)

Most ofthe euglenoids are simple unicellular motile flagellates. They have no fir111
cell wall, and possess characteristics like protozoans. They have a contractile cnglcnl)i~l.;.cryplopl~vlcs.
vacuole. Cell surface is pellicle (thin membrane) and his helical; knob like ~li~~~~ll~tg~lli~lcs.
c l l r y \ t ~ p Ict
l~~
projections. Cell shape changes constantly (euglenoid-movements): Chloroplasts iirc: ~r~:dc~~nill;lllllyi~~~tly
tt~~iccll~~l:~~
show variety of shapes s ~ ~ as
c hdiscoid, ribbon like or stellate. Cells are biflagellate Some bitllogisls cc~nsitlcrtl~cu.
orl!anistiis lo hc Inorr rcli~lcd
but only one flagellu~nemerges anteriorly. lo Ihc :~nit~i;tl
kiltg(10111; I I I L ~
classify 1hc111 untlcr (?n>lcln~;l
The photosynthetic pigments located in the plastids include chlorophyll a, b and
carotenoids including @-carotene. Some euglenoids are also colourless.

A form of starch-paramylon is present as distinct granules. Oil droplets and

polyphosphate granules are also colnrnon in the cells.

Cells divide by binary fission. Many species produce cysts under adverse
conditions. Sexual reproduction is absent.
 Euglenoids occur in fresh water and brackish water and very coni~nonlyIn
polluted ponds and temporary rain water pools.

Examples: Euglena, Truchelonlonas, Ph~rcus.

5.4.7 Division DINOPHYTA (Dinoflagellates)

Cell wall consists of cellulose plates which are inside the plasma membrane. A
number of plates or body scales may be present on the cell wall. Cell structure is
complex. Majority of fonns-are unicellular and motile. Many dinoflagellates such as
N o c r ~ l z ~are
~ ~ uluminescent.
, They glow in the dark when they are disturbed.

Most of these algae contain chlorophyll, ( I and c. and distinctive carotenoid specific
to dinoflagellates.

Reserve foods are mostly in the form of starch and oil.

Asexual method of reproduction is by cell division. Parent cell divides into a

number of aplanospores or zoospores or non-motile cells. Sexual reproduction has
been receritly reportcd, gametes are smaller than the vegetative cells and the
fusion is isogamous. Formation of cysts with or without gametic fusion -is also
fo~~nd.
Goliyaulax protluce nerve tosills
that kill tish. shrlltisll arc not Dinoflagellates are mostly found as ~iiarine phytoplankton, sometimes as 'red
killed by toxin bul they tide' blooms. Many occur as sy~nbiontsin marine animals like corals
accunlulillc as norvc loxins.
when I i ~ ~ r n ncunsume
~is
(zooxanthellae).
contaminated shell fish.
they devclop food poisoning. Examples: Noctilucu, Gonyuula. Peridin~vn~,
Cerufiz~rtl.

I
Ceratium

", Peridinium

1-ig. 5.12 : 5lc111bcl-sof Division Dino1,hytr.

Fig. 5.13 :Scanning clcctron a~icrographo f ~ rmarine planktonic dinoflagellate (Courtesy of P.
1)ryrnrndrn).

5.4.8 Division CRYPTOPHYTA (Crytomonads)

Unicellular motile organisms, when alive they are brown in colour. Several
genera are animal like in morphology and mode of nutrition, some are colourless and
saprophytic in nature.
Cells are without cell wall ovoid and dorsiventrally flattened. The two flagella are
apical and unequal in length. The chloroplasts may be single or many in a cell. In
some cryptomonads there are two, large parietal chloroplasts, or many disc like
ones.

Pigments include chlorophyll a, c, phycocyanin, phycoerythrin,and diverse

carotenoids.

Reserve photosynthate is starch.

Reproduction is by loilgitudinal division of the cell. Pal~nelloidforms may produce

zoospores. Sexual reproduction has not been reported so far.

Examples : C1yton7onas, CI7roon~onas.

5.4.9 Division BACIL1,ARIOPHYTA (Diatoms)
Diatoms (cut in halt) each cell
Mostly unicellular forms, some are colonial and filanlentous ilil structure. Cell is rnade up of two parts. The
wall is silicified, consisting of two perforated overlapping plates. It is highly larger part fitting liglily over
llie sliglitly smaller part like a
ornamented on the surface. Chromatophores are brownish in colour due to large petridish.
amounts of carotenoids.

Photosynthetic pigments are chlorophyll a and c, fucoxanthin, diatoxanthin and

diadinoxanthin.

Comrnon storage product is oil and chrysolaminarin.

Reproduction occurs by vegetative and sexual methods. Diatom cells unlike other
algae are diploid in nature. Sexual fusion is homothallic, within the individuals of
the same clone. Two amoeboid gametes fuse to form a zygote which develops
into an auxospore. Fusion inay be isogamous, anisogamous or oogamous type.

Diatoms are widely distributed in fresh water and sea as planktons, on mud
surfaces, moist rocks, and sand. They may even be epiphytic, epizoid or endozoid.

Large deposits of fossil diatom shells known as diatomaceous earth are mined and
used in various industries.
 Examples : Nuviculu, Cy~~rbella, Diatoriru and 1~r~1g11ut.i~.
Cosciriodi.~czls,

At the end we would like to point out that classification of algae is tentative and can
be improved by using new and advanced techniques like DNA fingerprinting etc.
which can clarify the genetic relatedness of organisms.

Fig. 5.14 : \Icttthcrs of I)t%ion Racillariopl~yta,Samc diatollas ;IS sccn under scrttni~il:clcctron
~~~icroscopc P.YD..yattantla~t).
( ( ' ( I I I ~ ~oCf S
, 1 In the following statements choose the correct alternative word given in
I parentheses.
It

:I i) Cell wall is absent in (Phaeopliyta/Euglenophyta).

ii) (ChrysophytdRhodophyta) are mostly unicellular.

tJ

..I iii) 'Uie storage material is paramylon in (Dinophytd Euglenophyta).

iv) 'The algae belonging to (DinopliytdBacillariophyta) are called diatoms

v) The cell wall of (DinophytdChrysophyta) is made of pectin, silica or

carbonates.

vi) The algae of Division (EuglenophytdBacillariophyta)reproduce sexually.

vii) The cells of (diatomsldinoflagellates) are diploid.

Trhlc 5.1 : Sclcctcd cl~arnctcristicsof t l ~ Algnl

c Divisions.

Form of
lDl~olosy~~tI~ctic
Ilivisians Cell I j p c s Ccll \IinI1 Composition Food
Pig~nc~~ts
storage
Chloropliqta Boll1 Cliloropliylls a and b. I1olysaccharidcs or cellulose Starch
unicellular and xanthopliylls, carotenes or ccll w;~llabsent
n~ulticellulnr
I1haeophyta ' Mostly Cliloropllylls u and c. Cellulose uitli alginates Lanlinarin
multiccllular fucoxantliin (oil)
Rhodophyta h4ostly Chlorophylls o and 61. Cellulose or pcctin. niany 1710ridian
multicellular pliycobilins with c a l c i ~ ~carbonate
~n starch
Xantliopliyta Unicellular and Chloropliylls o and c Cellulose or cell wall Chrysolanli-
niulticellular absent narin
Clirysopl>yta Mostly Cfiloropliylls o and c Cellulose or no cell wall Cliryolami-
unicellular and fuco\anthin sonic with silica or calcium narin
carbonate
Euglenophyta Mostly Cliloropliylls u and b. No cell \\.all: protein -rich I';imn~ylon
unicellular carotenes in gencra pcllicle (a starch)
with chloroplasts
Dinophyt:) Mostly Chlrophg lls a and b Cellulose or cell wall Starch
unicellular and peridinin (a absent Lipids
caroteno~d)
Cryptopliyta Clilorophylls cr and c. Cell wall absent Starch
Unicellular pliycohilins.
alloxanthin
Bacillariphyta Moslly Cliloropliylls a and c Cell wall silicilied Chrysolaniin
unicellular fitcox;~ntli~n arin

5.5 SYSTEMATIC POSITION OF SOME GENERA.

Family - Chroococcaceae,
Order - Chroococcales,
Division - Cyanophyta

Microcystis

Fan1 ily - Chroococcaceae,

Order - Chroococcales,
Division - Cyanophyta

Nosfoc

Family - Nostocaceae,
Order - Nostocales
Divisian - Cyanophyta

Family - Chlamydomonadaceae,
Order - Volvocales,
Division - Chlorophyta.

Family - Chlamydomonadaceae
Order - Volvocales,
Division - Chlorophyta.

Family - Ulotrichaceae,
Order - Ulotrichales,
Division - Chlorophyta.

Family - Ulvaceae,
Order - Ulotrichales,
Division - Chlorophyta.

Family - Oedogoniaceae,
Order - Oedogoniales,
Division - Chlorophyta.

Family - Coleochaetaceae,
Order - Chaetophorales,
Division - Chlorophyta.

Family - Lhaetophoraceae,
Order - Chaetophorales,
Division - Chlorophyta.

Family - Ectocarpaceae,
Order -- Ectocarpales,
Division - Phaeophyta.

Fucus

Family - Fucaceae,
Order - Fucales,
Division - Phaeophyta.

Family - Laminariaceae,
Order - Laminariales,
Division - Phaeophyta.
 Classification of Algnc

Family - Rhodoiiielaceae,
Order - Ceramiales,
I Division - Rhodophyta.
1

5.6 SUMMARY
In this unit you have learnt:
t
Algae have been grouped into two major types: prokaryotes and eukaryotes
because of the basic differences in the ultrastructure of the cells.

Cyariobacteria or blue-green aigae although related to bacteria, are grouped

with other algae because of the similarity in pigment composition and
. presence of oxygenic photosynthesis.
Eukaryotic algae can be classified into 9 divisions each sharing a large
e r corninon characters. All photosynthetic algae have chlorophyll a
n i ~ ~ n bof
and p-carotene, but other pigments may vary.
i
Three divis~onsCyanophyta, Rhodophyta and Cryptophyta have similar
phycobilin pigments - blue phycocyanin, and red phycoerythrin, otherwise
they are unrelated in any of the other characters.
-
Green algae (Division Chloropliyta) are unicellular, colo~iialand filamentous
in forms, motile and free floating. The photosynthetic pigments are chlorophyll
a, h, p-carotene and xanthophylls. Food is stored as starch. Though euglenoids
also contain chlorophyll u and h, but they are different from green algae.

Brown algae (Division Phaeophyta) are mostly marine, large, complex usually
~nulticellular,and non -motile. Tlie chlorophy lls are masked by brown
pigment fucoxanthin. Food is stored as oil and complex carbohydrate -
laminarin. Tlie zoospores and gametes are motile.

Red algae (Division Rliodopliyta) are marine, ~nulticellularand filamentous.

The chlorophyll is masked by pliycobilins. Food is stored as floredian starch.
There are no motile cells in the life cycle of the algae.
Members of Xanthophyta, Chrysophyta, Dinophyta and Cryptopliyta are
mostly unicellular. They contain chlorophyll o and c and are collectively called
chromophytes

In Xantliophyta, Chrysophyta and Dinopliyta the cell wall is liiade either of

cellulose or is absent. In Euglenophyta and Cryptophyta cell wall is absent.

5.7 TERMINAL QUESTIONS

I. Match the divisions of algae given in column 1 with the colours of algae
given below:

a) Rhodophyta i) Blue - green algae

b) Phaeophyta ii) Green algae
c) Xanthophyta iii)Golden brown
d) Clilorophyta iv) Red algae
e) Chrysophyta V) Brown algae
1) Cyanophyta vi) Yellow-green algae

2. List the major divisions of algae and briefly discribe their characteristics.
3. List the divisions of algae in which flagellated motile cells are absent.

............................................................................................

5.8 ANSWERS
Self-assessment Questions
5.1 a) These include
i) External morphology, ii) ultrastructure, iii) cliro~nosomeno,
iv) photosynthetic pigments, v) storage material, vi) DNA homolog)f,
vii) DNA banding, viii) enzy~nesand isoenzymes, ix) ccll wall composition

b) i) glycogen
ii) phycoerythrin
iii) mannitol, laminarin, rarely lipid droplets
iv) absent

C) (i) and (ii)

5.2 i) Euglenopliyta
ii) Chrysophyta
iii) Euglenophyta
iv) Bacillariophyta
v) Chrysophyta
vi) Bacillariopliyta
vii) diatoms
Terminal Questions
1) a) iv, b) V, C) vi, d) II
e) iii, f) I

2) Ref. to table 5.1.

3) Cyanophyta, Rhodopllyta