Here's a breakdown:
* Development: This is a broader term encompassing all the changes an organism undergoes throughout its life, from fertilization to adulthood.
* Ontogeny: This refers specifically to the development of an individual organism from a single cell (the zygote) to its final form.
Both terms describe the amazing process of cell differentiation, where initially identical cells specialize into diverse cell types that form tissues, organs, and ultimately, the entire organism.
