During exercise stroke volume increases because more blood is sent back to the heart due to the muscles squeezing blood in the veins
Answer:
Option A.
Explanation:
Air pressure decreases with increasing altitude.
An enzyme is a catalyst which means it changes the speed at which a chemical reaction occurs. It never alters the reaction in any way or changes nay chemical properties, only the speed at which it occurs and is completely absorbed in the meantime. The substrates that are reacting just have their reaction faster.
