Answer: Mutations can be good or bad.
Explanation:
Answer:
but you got to figure it out
The correct answer is that mammals use a closed, double loop , four chambered heart as a circulatory system of the body.
The circulatory system of mammals is closed system that consists of four chambers, two articles and two ventricles. The deoxygenated blood comes into the heart from one loop and the oxygenated blood from other loop from the heart is circulated to the whole body. This is called as double circulation.
Answer:
Enzymes speed up the chemical reactions in living cells.
Explanation:
An enzyme is a biological catalyst and is almost always a protein. It speeds up the rate of a specific chemical reaction in the cell. The enzyme is not destroyed during the reaction and is used over and over.
Normally, oxygen from the blood cells supply your muscles with the energy it needs to carry out certain actions. However, when there isn't enough oxygen to support the muscles, it produces lactic acid, or fermentation, to make up for the oxygen. (That's why you get that burn-y feeling whenever you exercise!)