Question

The zygote is single cell and a human adult has about 100 trillion cells ?​

Answer 1

• The zygote undergoes cell division, or mitosis, in order to develop into an organism of trillions of cells. It also undergoes speciation early on in the development of the organism.
• In order to create an organism with 100 trillion cells, 50 trillion cells need to divide (one time of mitosis), and 25 trillion need to divide to make 50 trillion (two times of mitosis), and so on. The cell would have to repeat this process 40 times.