Final answer:
The observed characteristics that support the endosymbiotic theory include mitochondria having their own DNA, mitochondria and chloroplasts reproducing by binary fission, and chloroplasts lacking a peptidoglycan wall. Mitochondria being similar in size to bacteria also supports this theory.
Step-by-step explanation:
Supporting Characteristics of the Endosymbiotic Theory:
Evidence for the endosymbiotic theory comes from several key observations that parallel the characteristics of mitochondria and chloroplasts to those of bacteria. These characteristics include:
- A. Mitochondria have their own DNA, which is similar to bacterial DNA both in sequence and chromosome structure. Unlike nuclear DNA, mitochondrial DNA is reduced because many genes have moved to the host cell's nucleus.
- B. Mitochondria are not larger than most bacteria; in fact, they are similar in size, which is consistent with the notion that mitochondria could have originated from bacteria.
- C. Chloroplasts lack a peptidoglycan wall, which is a feature they share with certain types of bacteria, suggesting a common evolutionary path.
- D. Chloroplasts and mitochondria reproduce by binary fission, a method of reproduction like that of bacteria, rather than the eukaryotic process of mitosis. This further supports the theory due to the similarity in their reproductive processes.
These observations collectively support the hypothesis proposed by Lynn Margulis and others that mitochondria and chloroplasts originated from a symbiotic relationship with prokaryotic organisms, eventually becoming integral components of eukaryotic cells through millions of years of evolution.