What important gas did stromatolites (cyanobacteria) release into the atmosphere?

Place the steps tor the formation of the enzyme pepsinogen in correct order

In which situations is the principle of cross-cutting relationship useful in determining relative age?

Aperson is outside exercising. body temperature begins to rise, and the person starts to sweat. their body temperature then returns to normal, and the body stops sweating. a positive b negative c allosteric d homeopathic