3. ALGAE :-
The word algae is derived from the Latin word alga which means sea weeds.
The general term “algae” includes prokryotic organism – cyanobacteria, also
known as blue green algae, as well as eukaryoticorganisms (all other algae
species).
Algae are a diverse group of Aquatic organism that have the ability to
conduct photosynthesis.
Algae are found in a range of Aquatic Habitats, both freshwaterand
saltwater.
The study of algae is called algology or phycology.
4. SALIENT FEATURES :-
Live in moist and aquatic habitats
Unicellular or multicellular.
Plant body is a Thalloid.
Presence of chlorophyll and other photosynthetic pigments.
Autotrophic in nutrition.
cell maybe Uni-nucleated or multi-nucleated.
Cell wall is rich in cellulose.
Cell motility is due to the presence of flagella.
5. STRUCTURE :-
They are found in a varietyof forms and sizes. They can exist as
single cells and multicellularcells.
Lack true roots, stems and leaves, and a vascular system to
circulate waterand nutrients throughout their body.
It is broadly divided into two main categories:-
1. Unicellular
2. Multicellular
6.
7. UNICELLULAR :-
1. Motile:- A singlecell with flagellafor locomotion. Eg- chlamydomonas.
2. Non –motile :- A single non – motile cell carrying out all essential functions of life.
Flagellais absent. Eg- chlorella.
CHLORELLA
CHLAMYDOMONAS
8. MULTICELLULAR :-
Colony is formed by aggregation of individual cells.
1. Motile colony :- individual cells possess flagella. Eg- Vovox.
2. Non –motile colony :- individual cell in the colony lacks flagella.
3. Amorphous colony:- Numerous non- motile cells are embedded in a common
mucilaginous matrix. Eg- Tetraspora
4. Dendroid forms :- the phallus appears as tree like under microscope. Eg- Dinobryon
5. Filamentous :- cells arranged one upon the other in a definite sequence forming
filaments. Eg- Cladophora , Spirogyra
6. Heterotrichous form :- Presence of more than one type of filaments.
7. Parenchymatous forms :- Cell divisionand associated separation leads to the
formationof a parenchymarous body. Eg- Chara
10. REPRODUCTION :-
Algae are capable of reproducing through asexual or
vegetative methods and via sexual reproduction.
Asexual Reproduction involves the production of motile spores.
Vegetative methods includes simple cell division (mitosis) to
produce identical offspring and the fragmentation of the
colony.
Sexual reproduction involves the fusion of gametes (produce
individually in each parent through meiosis).
11. IMPORTANCE OF ALGAE :-
Probably the most important contribution of ALGAE to our
environment is the produced oxygen through photosynthesis.
Green algae, diatoms and cyanobacteria are the microalgae
species that are considered good candidate for the
production of biofuel.
Algae helps to keep atmospheric carbon dioxide levels stable
by storing the gas.
13. INTRODUCTION :-
Yeasts are eukaryotic, single-celled microorganisms.
1,500 species are currently identified(1% of all fungal species).
A microscopic fungi consists of single oval cell that
reproduce by budding.
They are capable of converting sugar into alcohol and
carbohydrate.
14. MORPHOLOGY OF YEAST :-
They are single cells fungi.
Size – generally, larger than most bacteria.
Yeast cell lacks flagellar and other organs for locomotion.
Cell wall is composed of thin chitinous cell wall.
The protoplasm is surrounded by cell membrane which contain
all the usual cell organelle like ribosomes, mitochondria,
nucleus, etc.
Vacuole is single, large and centrally located.
15. REPRODUCTION :-
Yeast generally reproduce by asexual methods such as budding
or fusion
Yeast lack sex organs.
Sexual reproduction in yeast is highly variable
16. ASEXUAL REPRODUCTION - BUDDING :-
It occurred during abundant
supply of Nutrition.
Parent nuclieus divide and
move towards daughter cell.
Enzymatic activities increases.
Septum formation and bud
separates into individual cells.
Small yeast cell are being
formed off of larger yeast cells.
This is called budding.
17. SEXUAL REPRODUCTION :-
Sexual reproduction is very rarely
in some of the yeasts.
Three different pattern of life
cycle found in different Genes –
1. Haplodiplobiontic life cycle
2. Haplobionticlife cycle
3. Diplobionticlife cycle
18. IMPORTANCE OF YEAST :-
1. Food industry
Bread making – for the manufacturing of
bread, yeast is mixed with white flour.
Fermentation alcool – breakdown of starch
and sugar by yeast into carbon dioxide and
ethyl alcohol in the presence of oxygen.
2. Use in Brewing industry
Beer – yeast is added to malted grains and
allowed to ferment.
Wine – yeast is naturally present on the skin’s
of grapes and can be used to naturally
ferment grape juice into wine.
19. IMPORTANCE OF YEAST :-
3. Medical use
Lowering high cholesterol- research
showed that taking a specific red
yeast product for 2-3 months could
significantly lower“bad cholesterol“.
4. Nutrition
Yeast is a good source of protein, B-
vitaminand minerals
