The oxygen revolution changed Earth's environment dramatically. Which of the following took advantage of the presence of free oxygen in the oceans and atmosphere?
A) the evolution of cellular respiration, which used oxygen to help harvest energy from organic molecules
B) the persistence of some animal groups in anaerobic habitats
C) the evolution of photosynthetic pigments that protected early algae from the corrosive effects of oxygen
D) the evolution of chloroplasts after early protists incorporated photosynthetic cyanobacteria
E) the evolution of multicellular eukaryotic colonies from communities of prokaryotes
Astronomers identified 12-billion-year-old white dwarf stars only 100 light years away from Earth
Animation of the apparent retrograde motion of Mars in 2003 as seen from Earth
The Sun as it appears from the surface of the Earth at Sunset.
The Tilt of Earth’s Axis
The minimum number of moles of oxygen needed to completely consume 4 moles of C3H8O is ...
Earth 340 Million Years Ago