True or False: It is presumed that peroxisomes evolved in proto-eukaryotes to remove toxic oxygen.

The statement is accurate because it reflects the evolutionary role of peroxisomes in early eukaryotic cells. Peroxisomes are organelles that contain enzymes responsible for various metabolic processes, including the breakdown of fatty acids and the detoxification of hydrogen peroxide — a byproduct of cellular metabolism that can be harmful to cells.

The assumption that proto-eukaryotes developed peroxisomes to mitigate the toxicity of oxygen is grounded in the context of the Earth's atmosphere during the time of the emergence of eukaryotes. As oxygen levels increased due to photosynthetic activity, organisms that could efficiently manage this toxic byproduct had a selective advantage. This adaptation likely played a crucial role in the survival and evolution of early eukaryotic life forms. Thus, the evolution of peroxisomes is seen as a vital step in the transition to more complex cellular architectures in response to an oxygen-rich environment.

In summary, peroxisomes are believed to have evolved in proto-eukaryotes for their critical role in detoxifying hazardous byproducts of oxygen metabolism, validating the statement as true.