Pg.no. 26
Four types of bacteria are recognized based on shape. They are
1. Cocci (Spherical shaped)
2. Bacilli (Rod shaped)
3. Sprillum (Spiral or corkscrew)
4. Vibrio (Comma Shaped)
On the basis of the number and arrangement of the flagella, bacteria are classified as
1. Monotrichous (Single flagellum at one end)
2. Amphitrichous (Tuft of flagella arising at both ends)
3. Atrichous (Without any flagella)
4. Lophotrichous (Tuft of flagella at one end)
5. Petritrichous (Flagella all around)
Figure 9.1 (Bacteria)
Fungi:
The conversion of sugar solution into alcohol and liberation of carbon dioxide is known as
fermentation.
Here the sugar solution is fermented and gives a smell. Wine, alcohol are prepared from the
molasses by the fermentation activity of the yeast etc,.
Yeast is a unicellular, saprophytic fungus. The cell is oval shaped. The nucleus is seen at one
end of the vacuole. The cytoplasm is shows the presences of organelle like endoplasmic
reticulum, ribosome, mitochondria, etc,. Fungi do not posses chlorophyll. Hence they are
incapable of photosynthesis. The study of fungus is called Mycology. They lead a parasitic
or saprophytic mode of life.
A black powdery spot with a network of thread like filaments called hyphaes is called
mycelium (bread mould) which changes the color of the bread.
Entamoeba hyistolytica – Amoebic dysentery