Final answer:
Spontaneous generation, a discredited belief that life could arise from non-living matter, was the concept that ended the spontaneous origin of life. Evidence for endosymbiosis includes separate DNA, similar replication processes, and double membranes in mitochondria and chloroplasts.
Step-by-step explanation:
The process that put an end to the belief in the spontaneous origin of life was spontaneous generation. This outdated concept suggested that life could arise from non-living matter; however, it was disproved by scientific experiments that confirmed life only comes from pre-existing life, contributing to the development of the modern cell theory.
Regarding endosymbiosis, evidence for this theory includes:
- The fact that mitochondria and chloroplasts have their own DNA, which is similar to bacterial DNA.
- These organelles replicate through a process similar to bacteria, known as binary fission, independently of the cell cycle.
- Mitochondria and chloroplasts have double membranes, consistent with the engulfing process of a larger prokaryotic cell taking in a smaller one.
Additional mitochondria are produced through the binary fission of pre-existing mitochondria.