I suppose it's a zygote. In haplontic life cycle haploid gametes fuse together creating the zygote (diploid) that promptly divides meiotically creating 4 haplontic cells serving as spores.
It is transplanted routinely to treat a variety of blood and bone marrow diseases, blood cancers, and immune disorders. More recently, stem cells from the blood stream (called peripheral blood stem cells) and umbilical cord stem cells have been used to treat some of the same blood-based diseases
It is d because pesticides run off into water, they are absorbed into soil , and they are left in the air , hope this helps :)
Nuclear envelope is the answer
