What are lophotrichous bacteria?
When tuft of flagella’ is present only at one pole of bacteria, it is called Tophotrichous.
What are (or differentiate between) amphitrichous and Peritrichous bacteria?
When tuft of flagella at each of two poles is present, bacterium is called Amphitrichous. When flagella surround the whole cell, bacterium is called Peritrichous.
Write down the function of cell wall in bacteria.
It determines the shape of bacterium. Cell wall also protects the cells from osmotic lysis.
Compare nucleoid with nucleus.
Nucleoid is a region in prokaryotes where chromosomes are present without nuclear membrane while nucleus is found in eukaryotes and is membrane bound structure having chromosomes and nucleolus.
Differentiate between spore and cyst.
Spores: They are metabolically dormant bodies. They are produced at a late stage of cell growth. Spores are resistant to adverse physical environment condition such as light, high temperature, desiccation, pH and chemical agents. Under favourable conditions they geminate and form vegetative cells.
Cysts: Cysts are dormant, thick-walled, desiccation resistant forms. They develop during differentiation of vegetative cells which can germinate under suitable condition. They are not heat resistant.
What are photosynthetic bacteria? Give two examples or Name the bacteria which are photosynthetic.
They use sunlight as a source of energy. During photosynthesis they use hydrogen sulphide (H2S) instead of water as hydrogen source and liberate sulphur instead of oxygen. For example, Chromatium (Purple sulphur bacteria), Chlorobium (green sulphur bacteria) and Rhodospirillium (purple non-sulphur bacteria).