Features Associated with Prokaryotic Cells

Introduction:
Prokaryotic cells are primitive cells that lack a nucleus and membrane-bound organelles. They are found in bacteria and archaea and exhibit several distinguishing features. In this response, we will discuss how many of the above features are associated with prokaryotic cells.

Gas Vacuole:
- Prokaryotic cells possess gas vacuoles, which are hollow structures that help them regulate buoyancy.
- These vacuoles enable the cells to move up or down in the water column to access sunlight or nutrients.

Single Envelope System:
- Prokaryotic cells have a single envelope system composed of a cell membrane and a cell wall.
- This envelope provides structural support and protection to the cell.
- The cell membrane regulates the movement of substances in and out of the cell, while the cell wall maintains cell shape and prevents bursting.

Cytoskeleton:
- Prokaryotic cells exhibit a cytoskeleton, although it is simpler than that of eukaryotic cells.
- The prokaryotic cytoskeleton is composed of protein filaments called actin and tubulin homologs.
- These filaments help in maintaining cell shape, cell division, and intracellular movement.

Non-cellulosic Wall:
- Prokaryotic cells have a cell wall, but it is composed of peptidoglycan rather than cellulose.
- Peptidoglycan is a unique molecule found only in bacteria and provides rigidity and protection to the cell.

Microfilaments:
- Prokaryotic cells possess microfilaments, which are thin protein filaments involved in cell movement and maintenance of cell shape.
- These microfilaments are composed of a protein called FtsZ and play a crucial role in cell division.

Cytoplasmic Streaming:
- Prokaryotic cells exhibit cytoplasmic streaming, a phenomenon where the cytoplasm moves in a circular motion within the cell.
- This streaming aids in the distribution of nutrients, enzymes, and other cellular components throughout the cell.

Lack of Cell Organelles:
- Prokaryotic cells lack membrane-bound organelles, such as mitochondria, endoplasmic reticulum, and Golgi apparatus, which are present in eukaryotic cells.
- Instead, prokaryotes have specialized regions within the cytoplasm, such as nucleoid (containing DNA), ribosomes (for protein synthesis), and inclusion bodies (storage of nutrients).

Conclusion:
Out of the above features, six are associated with prokaryotic cells. These features include gas vacuole, single envelope system, cytoskeleton, non-cellulosic wall, microfilaments, cytoplasmic streaming, and lack of any cell organelles. These characteristics help prokaryotic cells adapt to diverse environments, maintain their shape, move, and carry out essential cellular processes.

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