The term angiosperm means “seed vessel” and refers to the production of fruits. Every flower becomes a fruit, though these fruits might not always fit with our cultural perception of what it means to be a fruit. Once pollinated, the fertilized seeds are encased in a protective ovary whose structure can be specialized for different methods of dispersal, such as animal ingestion, animal attachment, flotation, or wind dispersal. This protective ovary and the encased seed or seeds are more commonly called a fruit. Inside the developing seeds, angiosperms provide an additional food source to the developing zygote, the endosperm. The endosperm is produced by a process called double fertilization where one sperm fertilizes the egg and another fertilizes a pair of haploid nuclei, which makes the endosperm triploid (3n).