Idk the timeline but from largest to smallest, this hierarchy includes eons, eras, periods, epochs, and ages.
Development is where the growth of the embryo occurs. After fertilization and implantation, the growth of the embryo occurs once it gets to the uterus. This is the part where the procedure where the embryo turns into a living being over time - depending on the animal that has the said embryo.
LOCAL ENVIRONMENT ISSUE:
People dump a lot of trash in the sea, and the sea creatures living there goes through a lot of trouble to live with all the muck getting in them. Of course, don't write it like that in your assignment - you'll get told off for the straight forwardness.
