Q. How can the hypothesis that asserts that chloroplasts as well as mitochondria were primitive prokaryotes that related in mutualism with primitive anaerobic eukaryotic cells be corroborated?

The described hypothesis is called the endosymbiotic hypothesis about the evolutionary origin of mitochondria and choloroplasts.

Mutualism is described as chloroplasts and mitochondria can offer energy and nutrients to the cell in exchange for protection. The hypothesis is strengthened since those organelles have their own protein, DNA and RNA synthesis machinery and they divide themselves through binary division like bacteria do.