ACTERIA, ARCHAEA AND VIRUSES List 3 significant roles of bacteria in the environ

Question

ACTERIA, ARCHAEA AND VIRUSES List 3 significant roles of bacteria in the environment. Name the 3 most common bacterial shapes. Prepare a table comparing the chemical differences between Gram positive and Gram negative cell walls Define the following bacterial structures and state the advantages of each: (a) capsul b) plasmid: and (e) endopsores Describe Distinguish between the organization of genetic material in prokaryotic and eukaryotic cells. Name 3 mechanisms by which cells generate genetic diversity In a series of steps, describe the following bacterial processes: (a) transformation; (b) transduction; (c) conjugation List 5 properties used to distinguish bacteria from Archaea. Prepare a drawing of a virus and label the following parts: (a) genome; (b) capsid, (c) envelope. Prepare a table to compare viruses, prions, and viroids. in a series of steps the most common mechanism of bacterial cell multiplication.

Explanation / Answer

1. Significant role of bacteria in the environment-

A.Bacteria plays a significant role in the environment as a decomposers. Bacteria degrades the complex organic matter (dead remains of organisms called detritus ) into simple and convert them into inorganic substance, thus helps in recycling of nutrients.

B. Bacteria plays a crucial role in Nitrogen fixation. Nitrogen is a very important macronutrient required by all the living organisms. No organisms other than bacteria has the ability to convert atmospheric nitrogen into ammonia by a process called Nitrogen fixation. This ammonia converts into nitrates and nitrites by the activity of nitrifying bacteria, and make it available to plants. All animals relay on the plants for their nitrogen source.

C. Bioremediation is a process of degradation of toxic chemical compounds present in the environment and that process is carried out by Bacteria. Bacteria helps in removal of toxic substances and let the other organisms live comfortably.

2. Three common bacteria shapes are spherical, rod and spiral.

Spherical- these are the round shaped bacteria termed as Cocci (singular is coccus)

Rod - these are the cylindrical shaped bacteria termed as Bacilli (singular Bacillus)

Spiral - these are spiral or curved bacteria termed as spirilla (singular spirillum)

(Apart from these three, comma shaped bacteria called vibrio is also there)

3. Difference between Gram positive and gram negative bacteria cell wall composition.

4.a. Capsule- Capsule is a polysaccharide layer that present above the cell envelope.

Capsule protects the bacteria and it enhance the disease causing ability of Bacteria. Capsule contains water that protects the bacteria from desiccation. Capsule also helps bacteria to fix to the host / any surface.

b. Plasmid- Plasmid is a small, circular double stranded DNA present in bacteria. Plasmid is a extrachromosomal DNA has its own replication mechanism. Plasmid carries the antibiotic resistance genes, that gives the bacteria resistance to antibiotics. Plasmids are extensively used in recombinant DNA technology.

c. Endospores- Endospores are the thick walled dormant spores produced by gram positive bacteria. These are produced during the unfavorable condition especially during the lack of nutrients. Endospores are resistant to all possible adverse environment conditions include UV radiation, desiccation, high temperature, freezing, and even to chemical disinfectant.

Sl.no. Gram negative Gram positive 1. Cell wall is made up of thin peptidoglycan layer Cell wall is made up of thick peptidoglycan layer 2. Lipid content is 20-30% Lipid content is less than 10% 3 Murein content is 10-20% Murein content is 70-80% 4 Teichoic acid is absent Teichoic acid is present

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.