Introduction of algae and general characteristics Fossil history of algae Endosymbiosis Theory Where are algae abound? Ecology Algal Blooms Eutrophication How are algae similar to higher plants? How are algae different from higher plants? Variations in the pigment constitution Prokaryotic vs eukaryotic algae............... Presentation BEST OF LUCK

1. Phycology
1

2. INTRODUCTION OF ALGAE AND
GENERAL CHARACTERISTICS
PHYCOLOGY=STUDY OF ALGAE
Phycology is the study of algae.
This discipline deals with the morphology,
ecology, classification, biochemistry, and
economic importance of different types of
algae.
Derived from two Greek words
o phycos meaning algae
o logos meaning understanding
2

3. 3
Derived from Latin word
• alga meaning seaweeds
Seaweed is
a macroscopic, multicellular, marine
algae that lives near the seabed. The term
includes some members of the red, brown
and green algae

4. FOSSIL HISTORY OF ALGAE
 3.5 billion years ago
 Cyanobacteria—first algae
 Prokaryotes—lack membrane bound organelles
(cyanobacteria that is a blue green algae)
 Later eukaryotes evolved—mitochondria, chloroplasts,
and nucleus with chromosomes containing DNA.
4

5. 5
Eukaryotic Algae

6. Endosymbiosis Theory
6

7. Where are algae abound? Ecology
 Alga are aquatic and found
both in fresh and salt water
 Kelp (large seaweed/algae
belonging to the brown algae)
form forest up to 50 m height
are the marine equivalent to
terrestrial forest.
 Some algae encrust with
carbonate, building reef-like
structures; Cyanobacteria can
from rock-like structures in
warm areas: stromatolites.
7

8. Where are algae abound?
 Algae grow or are attached to
animals and serve as camouflage
for the animal
 Live in the hollow hairs of polar
bears (and each of these ridges
contains
unicellular Cyanoderma and
Trichophilus blue green algae or
cyanophyte)
 Algae live in animals such as Hydra,
corals, or the ciliate Paramecium; in
corals they are referred to as
zooxanthellae
 Algae can cover trees or buildings
green.
8

9. Where are algae abound?
 Small algae live on the
other plant: epiphytes
(chlorella)
 Some algae live inside the
cell of other plant:
endophytes (Chondrus
crispus (Rhodophyta)
 Algae in free water:
phytoplankton
 Terrestrial algae: found in
moist shady soils or rocks
9

10. Where are algae abound?
 Algae live on the snow cover
of glaciers and in the brine
channels of sea ice.
 Symbionts: association of
algae and fungi produced the
lichens
 Benthos: Benthic algae usually
cover hard bottoms of the seabed
10

11. Algal Blooms
 An algal bloom is a rapid increase in the population of algae in
an aquatic system.
 Algal blooms may occur in freshwater as well as marine
environments.
 Algae can be so dominant that they discolor the water
 Higher amounts of nutrients are usually the cause of algal bloom
(phosphorus and nitrate availability)
 Algal blooms can have harmful effects on life and ecosystem:
 Reduced water clarity causes benthic communities to die off
 Fish kills are common effects
 50% of algal blooms produce toxins harmful to other organisms,
including humans
 Algal blooms effect food web structure and species composition
 Algal blooms is the source of Eutrophication 11

12. Eutrophication
 “The process by which a body of water acquires a high
concentration of nutrients, especially phosphates and
nitrates. These typically promote excessive growth of
algae. As the algae die and decompose, high levels of
organic matter and the decomposing organisms deplete
the available oxygen in water body, causing the death of
other organisms, such as fish. Eutrophication is a natural,
slow-aging process for a water body, but human activity
greatly speeds up the process.”
12

13. 13

14. Summery of the lecture one
 We can find Algae in different Size (from some microns to more than 60
meters)
 We can find Algae in different region (soil, water, animal , plants … etc)
 Some of algae are prokaryotes and others are eukaryotes.
14

15. Summery of the lecture one
 In the aquatic ecosystems we can find algae as :
 Attachment:
o Epipelic / on the clay
o Epipzamic / on the sand
o Epilithic / on the rocks.
o Epiphytic / on the plants
o Epizoic / on the animals
o Endozoic / in the animals body
o Endophytic / in the plants body
15

16. Summery of the lecture one
 According to environments we can subdivided Algae
in to :
 Halophyts: in region with high salinity.
 Thermophyts: in region with high temperature.
 Cryptophyts: in the region with low temperature.
16

17. Lecture two
17

18. ALGAE
 How are algae similar to higher plants?
 How are algae different from higher plants?
18

19. Similarities
Presence of cell wall—mostly
cellulosic.
Autotrophs/Primary
producers—carry out
photosynthesis
Presence of chlorophyll a
19

20. Differences
 Algae lack the roots, stems, leaves,
and other structures typical of true
plants.
 Algae do not have vascular tissues—
non vascular plants
 Algae do not form embryos within
protective coverings—all cells are
fertile.
 Variations in pigments.
 Variations in cell structure—unicellular,
colonial and multicellular forms.
20

21. PROKARYOTIC VS EUKARYOTIC ALGAE
Prokaryotes
---No nuclear region and
complex organelles—
chloroplasts, mitochondria,
golgi bodies, and
endoplasmic reticula.
-- Cyanobacteria. Chlorophylls
are on internal membranes of
flattened vesicles called
thylakoids-contain
photosynthetic pigments.
Phycobiliproteins occur in
granular structures called
phycobilisomes.
21
 Prokaryote algal cell
Source: http://www.botany.hawaii.edu/faculty/webb/BOT311/Cyanobacteria/Cyanobacteria.htm

22. PROKARYOTIC VS EUKARYOTIC ALGAE
22
 Prokaryote algal cell
Source: http://www.botany.hawaii.edu/faculty/webb/BOT311/Cyanobacteria/Cyanobacteria.htm

23. Prokaryotic and Eukaryotic Algae
 Eukaryotes
---Distinct chloroplast, nuclear
region and complex
organelles.
--- Thylakoids are grouped into
grana
pyrenoids are centers of carbon dioxide
fixation within the chloroplast of algae.
Pyrenoids are not membrane-bound
organelles, but specialized areas of the
plastids that contain high levels of
ribulose-1,5-bisphosphate
carboxylase/oxygenase
23
granum with a
Stack of thylakoids
pyrenoid

24. Quiz:
Please, in short, Clarified:
What is Eutrophication?
What is pyrenoid?
24
Don’t be Cheat
If you did you are
cheater

25. Forms of Algae
 BODY OF AN
ALGA=THALLUS
 Thallus: entire body that
lack root stem and leaves
lacking vascular system
 DIVERSITY IN
MORPHOLOGY
----MICROSCOPIC
Unicellular, Colonial and
Filamentous forms.
25

26. Forms of Algae
26
MACROALGAE

27. Forms of Algae
27
MICRO ALGAE

28. Forms of Algae
1. Unicells: single cells, motile
with flagellate (like
Chlamydomonas and Euglena) or
non-motile (like Diatoms)
28

29. 2. Multicellular form: these are in six forms:
1. Colonies:
 Assemblage of individual cells with variable or constant number of cells
that remain constant throughout the colony life in mucilaginous matrix
(containing an extracellular matrix made of a gelatinous glycoprotein),
these colonies may be motile (like Volvox and Pandorina) or non-motile
(like Scendesmus and Pediastrum).
29

30.  Coenobium:
Colony with constant number of cells, which cannot
survive alone; specific “tasks” among groups of cells
is common (is a colony containing a fixed number of
cells, with little or no specialization)
30

31. 2. Aggregations: is aggregation of cells that have
ability to simple division (so, its colony but
unconstant in form and size), the aggregations
are in several types:
• Palmelloid form: non-motile cells embedded in
mucilage (like Tetraspora).
31

32. •Dendroid form: resembling a tree in
form or in pattern of growth (Dinobryon).
32

33. •Amoeboid or Rhizopodial form such as
Chlorarachnion.
33

34. 3. Filaments: daughter cells remain attached after
cell division and form a cell chain; adjacent cells
share cell wall (distinguish them from linear
colonies); maybe unbranched (uniseriate such as
Zygnema and Ulthrix) or branched (regular
multiseriate such as Cladophora or unregular
multiseriate such as Pithophora).
34
Cladophora
Pithophora

35. 4. Coenocytic or siphonaceaous forms: one large, multinucleate cell
without cross walls such as Vaucheria
35

36. 5. Parenchymatous (such as Ulva ) and algae: mostly
macro-scopic algae with tissue of undifferentiated
cells and growth originating from a meristem with
cell division in three dimensions
36

37. ; pseudoparenchymatous (such as Batrachospermum)
pseudoparenchymatous superficially resemble
parenchyma but are composed of apprised filaments
37

38. 6. Erect thallus forms: Thallus, from Latin word
(thallos), meaning a green shoot or twig, is an
undifferentiated vegetative tissue ( leaves, roots,
and stems) of some non-mobile organisms such as
Chara and Nitella.
38
Chara

39. CELLULAR ORGANIZATION
 Flagella=organs of locomotion.
 Chloroplast=site of
photosynthesis. Thylakoids are
present in the chloroplast.
The pigments are present in
the thylakoids.
 Pyrenoid-structure associated
with chloroplast. Contains
ribulose-1,5-bisphosphate
Carboxylase, proteins and
carbohydrates.
 Eye-spot=part of chloroplast.
Directs the cell towards light.
39
Source: A Biology of the Algae
By Philip Sze, third edition, WCB MCGraw-Hill

40. Variations in the pigment
constitution
 Chlorophylls (green)
 Carotenoids (brown, yellow or red)
 Phycobilins (red pigment-phycoerythrin
blue pigment –phycocyanin)
40

41. Summery of lecture two:
41
Unicellular Multicellular
1. Colonies
2. Aggregations
•Palmelloid (Tetraspora)
•Dendroid (Dinobryon)
•Amoeboid (Chlororachnion)
3.Filaments
4. Coenocytic / Vaucheria
5.Parenkematus/ Ulva
6. Psedoparenkematus / Batrachospermum
7. Erect thallus / Chara

42. Quiz of lecture two
What is Pyrinoid ?
What is Parenchymatous algae?
42
Don’t be Cheat
If you did you are
cheater

43. Lecture Three
43

44. Growth in algae
1. Diffuse or generalized growth: (Ulva).
2. Localized growth:
a. Apical growth: (Chara, Cladophora).
b. Basal growth: (Bulbochaete).
c. Intercalary growth: (Laminaria, Oedogonium).
d. Trichothallic growth: (Ectocarpus) (at the base of filament in algae)
44

45. Growth in algae
45
Tricothallic
Apical and intercalary

46. Reproduction in algae
The reproduction of algae can be discussed
under two types, namely, asexual reproduction
and sexual reproduction. The former type refers
to reproduction in which a new organism is
generated from a single parent. In case of sexual
type, two haploid sex cells are fused to form a
diploid zygote that develops into an organism.
Let's discuss in brief about the asexual and sexual
reproduction in algae along with examples.
46

47. 47
First: Asexual Reproduction includes:
1. Vegetation reproduction:
a. In unicellular algae: simple cell division some
time called binary fission (such as Gleocapsa).
b. In multicellular (colonies, filamentous, thallus,
etc) by:
 Fragmentation such as Microsystis.
 Hormogonia: A small, motile filament, formed by
some Cyanobacteria, that detaches and grows
by cell division into a new filament such as
Oscillatoria.
 Propagules: a structure capable of producing a
new individual such as Sphacelaria.

48. Vegetative reproduction
48
Cell Division
A cell could not keep growing bigger forever. Food molecules could not
reach the inside of a large cell fast enough to keep it alive. So when a cell
reached a certain size it had to divide into two smaller cells called
daughters. The daughters grew and, when they reached that certain size,
they too divided, this processes called binary fission.
But this caused a problem, Why?.

49. Vegetative reproduction
49
Hormogonia in Oscillatoria

50. Vegetative reproduction
50
Propagules

51. 2. Another method of asexual reproduction in algae is by formation of spores;
the algal species Ulothrix, Chlamydomonas and Chlorella reproduce by this
method. Depending upon the algal species, the spores can be produced in
normal vegetative cells or specialized cells called sporangia. They are either
motile called zoo spores or non motile called akinete spores.
(1) Zoospores are formed division of contents of parent cell. In filamentous
forms like ulothrix zoospores are formed from older cells of the filament.
Cytoplasm is divided to form zoospores which come out from mother cell
wall. Zoospores are formed in favorable condition. Zoospores are motile and
may be biflagellate or tetra flagellate or multi flagellate e.g. Vaucheria.
(2) Palmella Stage: Sometimes zoospores do not come out of mother cell but
remain surrounded by mucilaginous thread inside the mother cell. On division
they form colony shaped structure of Pumella. On liberation they form new
organisim e.g. Chlanydomonas.
51

52. 52
Ulotrix

53.  There are a lot of types of akinete spores such as:
• Autospores: immobile spores that cannot develop
flagella such as Chlorella. Plants like Scenedesmus and
some other chlrococales the resting spores develop all the
structures of the parent cell in which they are formed and
are similar to it except in size.
• Aplanospores: immobile spores that may nevertheless
potentially grow flagella. Aplanospores develop in
unfavourable conditions.
• Hypnospores: When alpanospores become thick walled
and undergo a long resting period they are called
hypnospores e.g. Sphaerella.
• Tetraspores: spores produced by a tetrasporophyte,
characteristic of red algae.
• Statospores: spores that are not actively discharged
from the algal fruiting body. Spores in resting stage.
• Auxospores: A spore in diatom algae that leads to
reformation of an enlarged vegetative cell.
53

54. Second: Sexual Reproduction:
54
As already mentioned, sexual reproduction takes
place by the union of male and female gametes.
The gametes may be identical in shape and size
called isogamy or different called heterogamy.
Some of the simplest forms of algae like Spirogyra
reproduce by the conjugation method of sexual
reproduction. In the process of conjugation, two
filamentous strands (or two organisms) of the
same algae species exchange genetic material
through the conjugation tube. Among two strands,
one acts as a donor and another serves as a
receiver. After exchanging the genetic material,
two strands separate from each other. The
receiver then give rise to a diploid organism.

55. Second: Sexual Reproduction:
55
Isogamy: is the form of sexual reproduction in which the gametes
produced are identical in shape, size and motility. There is no
structural distinction between "male" and "female" gametes. Pairs of
isogametes align themselves with their flagellar poles touching and
after several seconds, the motile gametes fuse to form a single, non-
motile, diploid zygote.

56. Second: Sexual Reproduction:
56
Isogametes, less commonly, may be non-motile structures. A
specific example exhibiting non-motile isogametes is the
reproductive process known as conjugation, in Figure below, the
conjugating Spirogyra identify the four stages of the process as
outlined.
Isogamy in Spirogyra sp.

57. 57
A. Resting filaments of alga cells.
B. Formation of conjugation tubes between two adjacent
filaments.
C. Cytoplasmic contents of each cell form a compact mass,
representing an isogamete. The isogametes from one
filament migrate through the conjugation tubes into the
adjacent filament.
The two isogametes unite to form a zygote. Each zygote
eventually undergoes meiosis to form four haploid cells. One
haploid cell will form a new filament by mitosis, the other
three degenerate.

58. 58
Heterogamy
In heterogamy, two different types of gametes are produced.
The male gamete, the sperm cell, is typically very small,
highly motile and is produced in very large numbers. The
female gamete, the egg cell, is much larger and non-motile,
called Oogamy. Fewer female gametes are produced but each
is usually afforded some protection. Heterogametes are also
produced by higher plants and animals.
Oedogonium sp. is a green alga that produces
heterogametes. The figure bellow illustrates the life
cycle of this alga. You can locate a mature egg cell and
the small male filaments, which are the site of sperm
production, the egg cells and male filaments are usually
adjacent to one another on the same algal strand.

59. 59
Heterogamy in Oedogonium sp.

60. SEXUAL REPRODUCTION
 ISOGAMY-Both gametes have flagella and similar in size and morphology.
 ANISOGAMY-Gametes have flagella but are dissimilar in shape and size. One
gamete is distinctly smaller than the other one.
 OOGAMY-gamete with flagella (sperm) fuses with a larger, non flagellated
gamete (egg).
60

61. 61
REPRODUCTION
Vegetative
Cell
divisions/Fragmentation
=part of the filament
breaks off from the rest
and forms a new one.
Asexual Reproduction
Zoospores after losing their flagella,
form new filaments. No sexual fusion.
Sexual-
Gametes

62. 62
a, b, and c are zoospores
d, e, and f are aplanospores
g, and h are hypnospores
K is autospores.
L is Isogamous, m is Anisogamous, and n
is Oogamous

63. 63
•Gametes look like vegetative cells or very different
•Isogamy: both gametes look identical
•Anisogamy: male and female gametes differ
morphologically
•Oogamy: One gamete is motile (male), one is nonmotile
(female)
•Monecious: both gametes produced by the same
individual
•Diecious: male and female gametes are produced by
different individuals
•Homothallic: gametes from one individual can fuse
(self-fertile)
•Heterothallic gametes from one individual cannot fuse
(self-sterile)

64. The life cycles in algae
64
•Three different types of life cycle,
depending on when miosis occurs, the
type of cells produced, and if there is
more than one free-living stage present
in the life-cycle.

65. The life cycles in algae
65
•Life-cycle I (haploid life cycle): (primitive life cycle)
It is the major part of life-cycle (vegetative plant body)
remains in haploid state and gametes are produced by
mitosis. Gametes are fused to form diploid zygote. In zygote
meiosis takes place and germination of the zygote (zygotic
meiosis) also referred to as haplontic life cycle (haploid
vegetative body). The zygote is the only diploid stage in such
cycles.

66. The life cycles in algae
66

67. The life cycles in algae
67
•Life-cycle II (Diploid life cycle): (Advanced life cycle) In
this case vegetative phase is diploid. Haploid gametes are
formed by meiosis. These gametes fused to form diploid
zygote. On germination, zygote divide by mitosis to form
vegetative body and also referred to as diplontic life cycleInt
such cycles all life form is diploid except gametes.

68. The life cycles in algae
68

69. The life cycles in algae
69
•Life-cycle III (Diplobiontic life cycle): These cycles present an
alternation of generation between two different phases
consisting in a haploid gametophyte and a diploid sporophyte.
The gametophyte produces gametes by mitosis
The sporophyte produces spores through meiosis.
Alternation of generation in the algae can be isomorphic, in
which the two phases are morphologically identical as in Ulva
(Chlorophyta) or heteromorphic in which sporo- and
gametophyte look different.

70. The life cycles in algae
70

71. Basis of algal Classification
 the different groups of algae can be classified on the basis of a number of
characteristics.
1. Color has been an important means of classifying algae, and gives many groups
their names. However, other characteristics, such as type of photosynthetic food
reserve, flagella type, cell wall structure and composition, and life history, have
been important in further distinguishing the algal divisions.
71

72. Flagella
Locomotion in algae is largely
based on the action of flagella.
The figure below illustrates the
wide variety of flagella present
in the algae. The primary
distinctions used for
classification are the number of
flagella, their location on the
cell, and their morphology. Two
major types of flagella are
recognized: the smooth, or
acronematic, and the hairy, or
pleuronematic, types. The
smooth flagella generally moves
by whiplash motion and the
hairy flagella moves by a pulling
motion. 72

73. ECOLOGICAL DIVERSITY
 LAND---WATER
 FRESH WATER---MARINE HABITATS
 FLOATING (PLANKTONIC)—BENTHIC (BOTTOM DWELLERS)
 EPIPHYTES
73

74. 74