What were the first organisms to appear on earth? ?

The image shows ekgs of a person with normal heart waves and of a person having tachycardia. based on this image, what kind of condition is tachycardia? a. the heart beats abnormally fast. b. the heart beats abnormally slow. c. the right atrium of the heart stops working. d. the left ventricle pumps less blood to the aorta.

Photosynthesis converts light energy to chemical energy. which molecules are the end product of this transformation of energy in this reaction?

Acommon kind of mechanical weathering is called