How do the embryological development of different species reveal similarities of organisms that are not evident in the fully formed anatomy. Use the model to describe how scientists use patterns in embryology to show the relatedness of living things.

That the species evolved from a common ancestor. ... Descent with modification explains why organisms living today may be different from their ancestors,for example, by having different structures.

Explanation:

Studying the structures that develop during an embryo's various stages of growth is called embryology and can be used to show the genetic similarities that suggest certain patterns of evolution. Most embryos look similar in their early stages, but as they develop, the differences between species become more obvious.

i think it would be b. tissue because an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.