Tek 4A Enrichment

By: Courtney Roberts

HOW DID EUKARYOTES DEVELOP FROM PROKARYOTIC CELLS?

Prokaryotic Cells

Prokaryotes are relatively simple cells surrounded by a membrane and a cell wall with a circular strand of DNA containing their genes.

Eukaryotic Cells

Eukaryotic cells are more complex than prokaryotes, and the DNA is linear and found within a nucleus. Included in a eukaryotic cell is membrane bound organelles which presents the mitochondria. The mitochondria produces chemical energy and holds the key to understanding the evolution of the eukarotic cell.

Evidence supports the idea that eukarotic cells are descendants of seperate prokaryotic cells that joined together in a symbiotic union.

The mitochondrion itself seems to be the descendant of a free living bacterium that was engulfed by another cell and ended up staying, like a permanent house guest. The host cell profited from the chemical energy the mitochondrion produced, and the mitochondrion benefited from the protected, nutrient rich environment surrounding it.
This kind of internal symbiosis, one organism taking up permanent residence inside another and eventually evolving into a single lineage, is called ENDOSYMBIOSIS. Keeping in mind the fact that this is a very prominant evolutionary theory.