This document discusses phycology, which is the scientific study of algae. It defines algae as autotrophic plants that produce food through photosynthesis. It describes the classification of algae based on pigments, stored products, chloroplasts, and flagella. The major groups of algae are discussed including their characteristics, life histories, ecology, and economic importance. The roles of algae as primary producers, producers of water blooms, indicators of water conditions, and sources of food, medicine, and industrial products are also summarized. Reproduction methods in algae including vegetative reproduction, asexual reproduction through spores, and sexual reproduction through gametes are outlined. Algal blooms are described as uncontrolled growth of microal

1. Noakhali Science & Technology
University
Name:Morsheda Nur Tisha
Department Of Education,Year-
2,Term-1

2. Unit 1:Phycology
Learning outcomes
• At the end of this unit
learners will be able
to:
a.recognize major
groups of algal genera
b.understand details
about phytoplankton
c.explain the role of
algae in different
aspects
• Content:
• Classification of Algae based on pigments,stored
products,chloplasts & flagella
• Life history,general characteristics,ecology &
economic importance of major algal groups-
Cyanophyta,Cholorophyta,Rhodophyta,Euglenophyta
,Phaeophyta & Bacilllariophyta.
• Fresh water & marine phytoplankton with their
biological importance
• Importance of Algae as-
a.primary food producer
b.producer of water bloom
c.indicator of water condition
d.source of food,medicine,fodder
e.other economic & industrial products

3. What is Phycology
• Phycology is the scientific
study of algae. Also known
as algology , phycology is a
branch of life science and
often is regarded as a
subdiscipline of botany .

4. Algae
-Algae is an autotrophic plant
which prepare food by
photosynthesis.
• Characteristics:
• Algae are autotrophic,diverse group of
eukaryotic organisms, ranging from
unicellular to multicellular forms.
• Aquatic (fresh water and marine) and
terrestrial environment.
• They also occur in moist stones, soils, wood,
on snow and on ice.
• 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)

6. QS:

7. Reproduction in Algae
• Algae reproduced by 3 methods:
1:Vegetative reproduction:Cell
division,fission,fragmention,hormogo
nia,formation of adventitious
branches,tubers,buddings etc.are
the important vegetative
reproduction in algae
2:Asexual reproduction involves the
production of a motile
spore.Zoospore,aplanospore,hypnosp
ore,tetraspore,autospore,akinetes
etc are the important spore types in
algae

8. 3:Sexual reproduction
involves the union of gametes
(produced individually in each
parent through
meiosis).Autogamyhologamy,is
ogamy,anisogamy & oogamy
are the different types of
sexual reproduction of alage

9. Algal bloom
• Algae, in the form of algal blooms, get a bad rap
for creating toxic conditions in oceans and lakes.
• Algal blooms refers to the uncontrolled growth
of certain microalgae, which in turn leads to the
production of toxins, disruption of the natural
aquatic ecosystems.
• The blooms take on the colours of the algae
contained within them.
• The main toxin producers in oceans are certain
dinoflagellates and diatoms. In freshwaters,
cyanobacteria are the main toxin producers.
• The main cause of algal blooms is a phenomenon
called nutrient pollution. With nutrient pollution,
there is an excess of nitrogen and phosphorus,
which can push algae toward uncontrolled growth.
The phenomenon is caused by the fertilizers we
use in agriculture and animal manure

10. Economical importance
Positive impacts
1. At least a half of the total carbon dioxide fixation
on earth is carried out by algae through
photosynthesis.
2. Major component in aquatic food chain as primary
producers.
3. Porphyra, Laminaria and Sargassum are used as food.
4. Algin (brown algae) and carrageen (red algae) are
used as hydrocolloids, which is a fibrous structure
holds water and used to transport seedling.
5. Agar is used as commercial products.
6. Gelidium, Graularia are used to grow microbes, make
ice creams and jellies.
7. Chlorella and Spirullina are rich in proteins and used
as food supplements.
Negative impacts
1.Fish & other marine animals death-
loss of money & food sources.
2.Toxic algae bring infections up the
food chain which may result in death
or diseases.
3.Algal blooms can deolete the oxygen
& block the sunlight that other
organisms need to live.