Which of the following best describes embryology?

Embryology is best defined as the study of development from conception to birth, encompassing the complex processes that occur as a fertilized egg transforms into a fully developed organism. This field of study focuses on how cells divide, differentiate, and organize into the various tissues, organs, and systems that compose a living organism. It includes the examination of early development stages, such as zygote formation, cleavage, gastrulation, and organogenesis, all of which are critical in understanding how various factors can influence embryonic development.

While the other options mention relevant biological concepts, they do not capture the specific focus of embryology. The study of cellular processes relates to cell biology, which examines cellular functions and interactions, rather than the broader developmental focus. The inquiries into evolutionary changes pertain to evolutionary biology, which deals with how species and their traits evolve over extended time periods. Similarly, the behavior of organ systems typically falls under physiology, where the focus is on how organs and systems operate and interact in a fully developed organism, rather than the early stages of development that embryology emphasizes. Hence, the most accurate description of embryology is its concentration on development from conception to birth.