<span>blastocyst
The outer layers of the blastocyst turn in to the trophoblast after implantation. The trophoblast forms the placenta.</span>
2) Cross-fertilization makes for more variation in the traits of plants, giving them immunities and resistances to weather, pests, and disease.
Plant cells have a cell wall, but animals cells do not. Cell walls provide support and give shape to plants. Plant cells have chloroplasts, but animal cells do not.
Hope this helps :)