This is a concise, explanatory reference dictionary covering the fields of general biology, botany, zoology, anatomy, physiology, histology, cytology, embryology, genetics and breeding, biochemistry, biophysics, biometrics, systematics, evolutionary biology, ecology, virology and parasitology, molecular biology, gene and cell engineering, and biotechnology; it provides scientific definitions for nearly 7,000 terms that have gained widespread use in the rapidly evolving field of biology.