The discovery of a common ancestors in fossil record, the presence of homologies and nucleic acid similarities scientists decide, how to classify organisms

When is your respiration rate likely to change? a. when your intestines are digesting b. when your cells have too much glucose c. when your cells need more oxygen d. when your liver is working after a meal

What did not occur in the proterozoic eon a)the oxygen levels increase greatly in the atmosphere,b)the emergence of the eukarya , c)muti cella’s eukaryotic organisms began to diversify,d)anaerobic bacteria kept thriving with more oxygen

Which statement is true for bacteria a. bacteria have complex internal structures b. all bacteria are spiral in shape c. all bacteria cause disease in animals d. bacteria break down some foods