All 37 trillion cells in the human body came from?

all 37 trillion cell in the body originates from a single fertilized egg called a zygote. The zygote divides repeatedly to produce an embryo. These embryonic cells continue to divide, differentiating into all the cell types present in the body of all humans (and other mammals), from a new-born baby to an elderly adult.

answer; ///(b) it is composed of four protein chains and four heme groups;

the answer is a) cell division.

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