Based on current evidence, what process most accurately describes how chloroplasts and mitochondria evolved?
a.photophosphorylation
b.endosymbiosis
c.photosynthesis
d.cellular respiration
I personally think the answer is d.
Endosymbiosis, I picked D first and got it wrong
it was endosymbiosis thanks anonymous on apr 27 2019
The process that best describes how chloroplasts and mitochondria evolved is b. endosymbiosis.
Now, let me explain how we can arrive at this answer. Endosymbiosis is a theory that proposes that eukaryotic cells evolved from simpler ancestral cells that engulfed and formed a symbiotic relationship with primitive prokaryotic cells. According to this theory, chloroplasts and mitochondria are believed to have evolved through a process of endosymbiosis.
To understand this concept, we can look at the similarities between these organelles and bacteria. Chloroplasts and mitochondria have their own DNA, similar to bacteria, and they can also divide independently of the cell they reside in. This suggests that these organelles were once free-living bacteria that were engulfed by early eukaryotic cells.
The endosymbiotic theory proposes that a host cell engulfed a free-living photosynthetic prokaryote (which eventually evolved into chloroplasts) and a free-living aerobic prokaryote (which eventually evolved into mitochondria). Over time, these engulfed cells formed a mutually beneficial relationship with the host cell, providing energy (through photosynthesis and cellular respiration) while receiving protection and nutrients.
Therefore, while cellular respiration (d) is indeed an important process for cellular energy production and is involved in the functioning of mitochondria, the most accurate process that describes the evolution of chloroplasts and mitochondria is endosymbiosis (b).