How do we get our oxygen if plants do cellular respiration. If plants do cellular respiration and photosyntehsis shouldn't there be no oxygen in the air?

Scientist have long study the earths climate by looking at which of the following? the earths orbit. the earths rock layers. the antarctic ice. the earths oceans.

How did the research presented in the article affect scientists' understanding of the evolution of eukaryotes

Lola needs to sign 6 invitations. using stopwatch that measures time to tenths of a second, it takes lola 5.3 seconds to sign her full name. going by the accuracy of the stopwatch, which is the most accurate determination for the number of minutes lola needs to sign all 96 invitations