Circulatory system.....circulates blood (a vital delivery system of oxygen) throughout the whole body when tissues need it the most and with a constant supply.
Answer:
If there are no animal cells, then life on earth would not exist. Also plants would dominate.
Explanation:
Often referred to as the molecule of life, DNA (deoxyribonucleic acid) is found in almost all living things. It acts as a type of chemical code that contains instructions, known as genes, for how the body and all its different parts grow, develop, function, and maintain themselves.
