Two biologists co-discover a population of single-celled eukaryotes that do NOT have mitochondria. Whoa! One biologist thinks the cells must be from a lineage that never underwent endosymbiosis, but the second biologist thinks endosymbiosis happened at some point, but the mitochondria were later lost. Which of the following provides the BEST evidence to support the second biologist?

A. the cells are incapable of surviving without sunlightB. sexual reproduction is never observedC. the nuclear genome has some genes from proteobacteriaD. the cells also contain chloroplasts

Option C

Explanation:

The amitochondriate eukaryotes may have genes that have been derived from purple alphaloproteobacteria because they do not have the mitochondria which is needed to optimize energy production in the presence of oxygen, can live and exist in a condition with little to no oxygen which is a characteristic of proteobacteria and hence are anaerobes obtaining energy by anaerobic respiration. They may have also undergone the endosymbiont theory but due to their environment which has little to no oxygen. They do not have a need for the mitochondria organelle and in the process lose this organelle.

most likely to see nocturnal animals

this is true, assuming that the allele is completely recessive and incomplete dominance is not a factor.