Cereal and Wheat berry

Cereal noun - Grass whose starchy grains are used as food: wheat; rice; rye; oats; maize; buckwheat; millet.

Wheat berry and cereal are semantically related. In some cases you can replace phrase "Wheat berry" with "Cereal", this terms are similar.

Wheat berry noun - Grains of common wheat; sometimes cooked whole or cracked as cereal; usually ground into flour.

Cereal and wheat berry are semantically related. You can use "Cereal" instead a noun phrase "Wheat berry".