Acids turn blue litmus paper .

Red
Yellow
Green
Blue

Which of the following happened during the precambrian era? the first prokaryotic cells the first eukaryotic cells development of photosynthesis all of the above

Which of the following requires the use of energy and the of transport proteins to move a molecule across a cell membrane?

How do you suppose living conditions differ between the country furthest along in the demographic transition compared to the country earliest in the transition? how would living conditions in these two countries affect both birth and death rates?