Which observation would provide the strongest evidence that a protist belongs to the Excavata?

Which of the following events most directly contributed to the rise of aerobic cellular respiration?

Which of the following would provide the strongest evidence that two populations belong to the same biological species?

Healthy individuals of Paramecium bursaria contain photosynthetic algal endosymbionts of the genus Chlorella. The Chlorella provide their hosts with glucose and oxygen, and P. bursaria provides its Chlorella with protection and motility.   Which term best describes the symbiotic relationship of well-fed P. bursaria to Chlorella?

Which of the following provides the strongest evidence supporting the endosymbiotic origin of chloroplasts?

According to the phylogenetic tree in the figure below, what type of evolutionary group does G. intestinalis constitute?

Which observation provides the strongest support for the hypothesis that life originated through chemical evolution?

Which of the following characteristics is most useful for constructing modern phylogenetic trees?

Green algae and plants are placed in the same phylogenetic group. Which of the following statements presents evidence to support this classification?

A scientist discovers a prokaryote that obtains energy from sunlight and uses CO₂ as its carbon source. This organism would be classified as a: