Acovalent bond is formed when atoms share electrons true or flase

In a cladogram' when does a group of organisms branch off

The image below shows a common blood pressure gauge. what does this device do? a. measures the level of oxygen present in the blood b. measures the pressure of blood when the lungs expand and compress c. measures the electrical activity of the heart d. measures the pressure of blood when the heart contracts and relaxes

Which macromolecule catalyzes chemical reactions this be considered enzyme chemical reactions thus he considering enzymes