A cell that just fertilized has to divide 6 times to form a 64 cell blastomere.
<u>Explanation:</u>
Human reproduction begins with the fusion of male gamete sperm and female gamete ovum. The fusion of sperm and ovum forms the zygote that is diploid. The zygote then undergoes mitotic division to develop into embryo.
The zygote first divides into two and the two individual cells divide again to form four individual cells and so on. Thus the number of cells after each division can be represented by the equation 
where n is the number of divisions. in the question it is given that the blastomere has 64 cells.
n=6
This means that the fertilized cell has to divide 6 times to develop into 64-celled blastomere.
Biotic factors of an ecosystem are all the living organisms that affect other organisms in an ecosystem and include animals, plants, microorganisms, dead organisms, and even animal waste. Example of biotic factors include: Grass as producers (autotrophs).
The things that you throw away are buried in the ground. They are buried in something known as a 'landfill'. These are very deep holes which hold A LOT of trash. The problem is, there are only a few locations left in most western countries which actually have space to hold all of the waste people are generating.
<span>The chemical symbol K(Potassium) comes from kalium, the Latin word for potash. Potassium is a soft, silvery-white metal. Potassium can be used for Potassium Hydroxide (KOH) which is used to make soap. Potassium can also be used for making salt.</span>
The skin, mucous membranes, and endothelia throughout the body serve as physical barriers that prevent microbes from reaching potential sites of infection. Tight cell junctions in these tissues prevent microbes from passing through.
