Question

Describe, in detail, the well-accepted theory in biology that postulates certain eukaryotic organelles evolved from specialized prokaryotes. Include the name of the theory, name of the organelle, the function the prokaryote provided, and two lines of evidence that supports the theory.

Answer 1

The endosymbiotic theory explains the evolution of certain eukaryotic organelles from prokaryotes. Two pieces of evidence for this theory are the presence of double membranes and the presence of their own DNA in mitochondria and chloroplasts.

Step-by-step explanation:

The well-accepted theory in biology that explains the evolution of certain eukaryotic organelles is the endosymbiotic theory. According to this theory, organelles such as mitochondria and chloroplasts evolved from ancient, free-living prokaryotes that invaded primitive eukaryotic cells. The prokaryotes provided specific functions to the host cells, such as energy production in the case of mitochondria and photosynthesis in the case of chloroplasts.

There are two lines of evidence that support the endosymbiotic theory:

1. The presence of double membranes: Mitochondria and chloroplasts have double membranes, which is similar to the way prokaryotes have an outer membrane and inner membrane. This suggests that these organelles were once independent cells that got engulfed by eukaryotic cells.
2. Presence of their own DNA: Both mitochondria and chloroplasts have their own DNA, similar to prokaryotes. This DNA is separate from the nuclear DNA. This suggests that these organelles were once independent cells with their own genetic material.