What are Prokaryotes?

About Prokaryotes:

• They are single-celled organisms that lack a distinct nucleus and other membrane-bound organelles. 
• Features
  • Shape:They come in various shapes and sizes (0.5-5 µm), with four basic shapes being rod-like (bacillus), spherical (coccus), comma-shaped (vibrio), and spiral (spirillum).
  • Cell organisation:They have a basic structural organisation, which includes a cell wall (except in mycoplasma), cytoplasm, and a plasma membrane. However, they lack a well-defined nucleus.
  • Organelles:They  lack membrane-bound organelles, except for ribosomes.
  • They do have unique structures called mesosomes, which are extensions of the plasma membrane used for various functions.
  • Reproduction:They reproduce primarily through binary fission, a type of asexual reproduction.
  • DNA:Most prokaryotic cells have a single chromosome, which carries hereditary genes in the form of DNA.
• Prokaryotes include bacteria and “archaea”, another type of single-celled organism.
• These organisms are thought to be the oldest cell-based lifeforms on Earth.
• Habitat: They thrive across the entire planet, on land and in water, from the tropics to the poles.
• Ecological significance: They play a crucial role in the world’s food chains, helping support the nutrient needs of fish humans catch and eat.
• Marine prokaryotes grow extremely fast – a process that emits a lot of carbon.