A steak comes from a beef animal. Leather is made from the hides of cattle and pigs. Blue jeans are made out of a cotton plant. Wool can be used to make clothes and blankets. Swine is another word used to talk about pigs.
Potatoes grow on trees.
The part of the onion plant that we eat is the flower. Wheat is a seed. Most of the bread in grocery is made of corn. Flour is any ground up grain like wheat. Spaghetti noodles are mostly made of wheat.