You can find biology mock tests on various educational websites, coaching institute portals, and government exam preparation platforms. Websites like NTA, NEET official sites, and learning apps such as Unacademy, Vedantu, and BYJU’S offer free and paid mock tests. Many online forums and Telegram groups also share PDFs of practice tests. Additionally, books from publishers like Arihant and MTG provide mock test series. Ensure you choose reliable sources for accurate and updated content.