This contributed volume convenes selected, peer-reviewed works presented at the BIOMAT 2021 International Symposium, which was virtually held on November 1–5, 2021, with its organization staff based in Rio de Janeiro, Brazil.In this volume the reader will find applications of mathematical modeling on health, ecology, and social interactions, addressing topics like probability distributions of mutations in different cancer cell types; oscillations in biological systems; modeling of marine ecosystems; mathematical modeling of organs and tissues at the cellular level; as well as studies on...