Why can sharks have 3000 teeth in their lifetime?

Sharks do not have 3000 teeth in their lifetime. Sharks have multiple rows of teeth, and they can lose and regrow them throughout their lives. A typical shark may have around 50 teeth in each row, and they may have several rows of teeth at a time. As a shark loses a tooth, a new one will grow in to replace it. This process can happen multiple times throughout a shark's life, but it does not mean that a shark will have 3000 teeth in its lifetime.