Answer:
1) To form a multicellular organism, a zygote must divide into 16 cells which produces ball structure called a morula. After that, morula is converted into a structure called blastula.
2) Adult stem cells are responsible for the maintenance of tissues and repair the damage tissues in the body. It is also called somatic stem tissue. It increase in number through cell division.
Ar(Argon) have an electron affinity measuring closest to zero .
B would be the closest thing to wht you are looking for.
the observable universe is estimated to contain 200 billion to two trillion galaxies.
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