Fertilized Egg - Sometimes referred to as a zygote, this is the resulting initial cell formed when a sperm cell unites with an egg cell.⏎
Endemic - The baseline level of disease usually present in a community.⏎
Exoskeleton - An external skeleton that protects and supports an organism, in contrast to an internal endoskeleton.⏎
Evolution - The change in heritable traits in a population of organisms over successive generations.⏎
Gene - The physical and functional unit of heredity made up of DNA. Every individual has two copies of each gene, one inherited from the mother and the other from the father.⏎