Bones consist of living cells embedded in a mineralized organic matrix. This matrix consists of organic components, mainly type I collagen – "organic" referring to materials produced as a result of the human body – and inorganic components, primarily hydroxyapatite and other salts of calcium and phosphate.
The answer is natural selection.
In natural selection, genotype variations that will increase the chance
of survival and reproduction of some organism are preserved and will be
inherited. Red and green colors of butterflies increased the chance of their <span>survival and reproduction, so these traits will pass to the next generation.</span>
<span>blastocyst
The outer layers of the blastocyst turn in to the trophoblast after implantation. The trophoblast forms the placenta.</span>
Answer:
yeah otherwise it would have being abnormal