in zoology

| chrysalis, casing, tegument, puparium (insects), shell

| ovum, egg cell, zygote (after fertilization), ootheca (insects), amniotic egg (reptiles, birds, mammals)

| nucleus, marrow

in botany

| pericarp (fruits), bract (leaves), shell, tegument (seeds)

| ovule (seed), oosphere (plants and algae), spore (ferns and fungi)

| kernel, pit, nut, seed, endosperm