Question

What are characteristics of prokaryotic cells?

Answer 1

Following are the characteristics of prokaryotic cells:

1. Nuclear material: DNA is naked and lies variously coiled in the cytoplasm. It is often called genophore, nuclear body or nucleoid.
2. Nuclear components: Nuclear envelope, nucleoplasm, nucleolus and histone covering of chromatin are absent.
3. Cell wall: It is present in bacteria and cyanobacteria. A cell wall is absent in mycoplasma or PPLO.
4. Flagella and fimbriae: Flagella are present in some bacteria only. The bacterial flagella are single-stranded as compared to 11-stranded flagella of eukaryotes.
5. Membrane-lined cell organelles: The prokaryotic cells lack mitochondria, endoplasmic reticulum, golgi apparatus, lysosomes ad centrioles.
6. Vacuoles: Typical vacuoles are doubtful. Instead complex gas vacuoles are found.
7. Ribosomes: Ribosomes are 70S as compared to 80S.
8. One-envelope system: In prokaryotic cells, membrane bound cell organelles are absent so that there is a single membrane that surrounds the cell. Hence, prokaryotes have a single membrane or one-envelope system.