For the answer to the question above,
the development of specialized tissues and organs in a multicellular organism's embryo occurs as a result of "<u><em>differentiation</em></u>"
It is the <span>process where a cell changes from one cell type to another.</span>
Answer:
Many <u>human activities</u> like burning of fossil fuels, cutting of trees, application of nitrogen-based fertilizers, etc can have a major impact on the <u>nitrogen cycle</u>. These human activities and other activities can dramatically increase the amount of biologically available <u>nitrogen</u> in an <u>ecosystem</u>.
<em>Hope it helps</em>
<em>:D</em>