Question

1. Distinguish among the various forms of bacteria.

2. How do bacterial chromosomes differ from chromosomes of eukaryotes?

3. There are two major groups of autotrophic bacteria, the ___ and the ____. The two groups use different energy sources in order to manufacture organic from inorganic compounds, but the carbon source for both group is ______.

4. Name some of the important roles played by prokaryotes in the world ecosystem.

Answer 1

Answer 1. There are various forms of bacteria basing upon their shape like-

• Some are spherical known as coccus.
• Some are rod shaped called bacillus.
• Some are comma shaped called vibrio.
• Some form chains and spherical in shape called streptococcus.
• Some occur in groups with spherical shape called staphylococcus.
• Some spherical bacteria occurs in group of 4 called tetrads.

Basing upon whether they can prepare their own food or not they are named as:

• Photoautotrophic. Use sunlight to prepare their food.
• Chemoautotrophic. Use chemicals to prepare their food
• Heterotrophic. They cannot prepare their own food,thus dependent upon others.

Answer. In prokaryotes like bacteria the genetic material is not packed as in eukaryotes, it is present in ill defined nucleus called nulceoid.

Chromosomes are formed by the coiling of chromatin, such condensation is absent in the prokaryotes. In eukaryotes, chromatin is condensed utilising histones, so compaction is quite high in them.

Answer 3. Photoautotrophs and chemoauto trophs. They both use inorganic form of carbon to prepare their food. Photoautotrophs use CO2 to prepare their food and chemoautotrophs utilise chemicals to form energy source.

Answer 4. The major roles played by bacteria are:

• They act as decomposers, help in converting complex form to the simpler one. Making earth a clean place to live in.
• They help in nitrogen fixation.
• They are used for antibiotic preparation.
• They are used in baking and brewing industry.
• They are used in bioreactors.
• They are used for carring biotechnological experiments.
• They are used for the preparation of chemicals, enzymes and important products.
• They are used to prepare biopesticides.