Valence shell
The number of electrons in the outermost shell of a particular atom determines its reactivity, or tendency to form chemical bonds with other atoms. This outermost shell is known as the valence shell, and the electrons found in it are called valence electrons.
Answer:
Specialized cells because they preform a specific function
Answer:
2)They have similarities in their embryonic stages that don’t exist in their adult forms
4)They all contain a backbone, or spinal column
Explanation:
In the embryonic development of vertebrates during the early stages of development there are great similarities. Vertebrates in the early stages as shown in the image are very similar and subsequently develop the structures of their own species that differentiate them.
The presence of notocorde is a characteristic characteristic of vertebrates and birds, fish, reptile amphibians and mammals have it since they are embryos to adults
