Question
Briefly describe the prokaryotic cell.
✓
Answer
The prokaryotic cells are represented by bacteria, blue-green algae, mycoplasma and PPLO (Pleuro Pneumonia Like Organisms) and lack a membrane-bound well-organised nucleus and double-layered membrane-bound organelles. There is no well-defined nucleus. The genetic material is basically naked, not enveloped by a nuclear membrane. In addition to the genomic DNA (the single chromosome/circular DNA), many bacteria have small circular DNA outside the genomic DNA. These smaller DNA are called plasmids. Lack of histone protein and there is no mitosis and sexual division in them. There is no complete development of membrane containing organelles in the cytoplasm.
Ribosomes are also of 70S type. The structure of flagella is also not 9 + 2. They lack mitochondria but due to infoldings of plasma membrane, mesosome are formed, through which respiration takes place. Nucleolus, nuclear membrane and nucleus are absent. Therefore, the genetic material remains scattered in the centre of the cell.
Ribosomes are also of 70S type. The structure of flagella is also not 9 + 2. They lack mitochondria but due to infoldings of plasma membrane, mesosome are formed, through which respiration takes place. Nucleolus, nuclear membrane and nucleus are absent. Therefore, the genetic material remains scattered in the centre of the cell.
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