Which of the following best describes the effects of water pollution on aquatic ecosystems?

How can scientists test their ideas about the origin of the universe if they can't physically interact with or study?

What is a codon and where is it found

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