Origins of Cells · Paper 1 — Free Biology HL Practice Questions

The Miller-Urey experiment circulated a mixture of methane, ammonia, hydrogen, and water vapour through electrical discharges for one week. Analysis of the resulting liquid revealed the presence of amino acids and other small organic molecules. Which statement most accurately describes the significance of this finding?

A biologist studies a unicellular eukaryote that lacks mitochondria but posses other membrane-bound organelles. She hypothesises that this organism diverged from the eukaryotic lineage before the endosymbiotic event that gave rise to mitochondria. Which observation, if true, would most directly challenge her hypothesis?