Invertebrates (and higher animals<>can be placed<>$$$two groups<>based<>on how they develop as embryos$$$they<>develop<>
There, the group of cells can embed in the uterine wall and develop into an embryo and placenta.
Invertebrates (and higher animals) can also be placed in one of two groups based on how they develop as embryos.
Invertebrates (and higher animals) can also be placed in one of two groups based on how they develop as what?