Despite differences, what features are common to bird, mammal, frog, and sea urchin gastrula embryos?Check All That ApplyBlastocoelBlastocoelCell movementsCell movementsDorsal lipDorsal lipMesoderm is internal, between ectoderm and endodermMesoderm is internal, between ectoderm and endodermPrimitive streakPrimitive streakSpherical embryoSpherical embryoThree distinct germ layers are formedThree distinct germ layers are formedYolk

The common features to bird, mammal, frog, and sea urchin gastrula embryos are:

1. Cell movements: During gastrulation, cells move to new positions to form the three germ layers: ectoderm, mesoderm, and endoderm.

2. Mesoderm is internal, between ectoderm and endoderm: In all these embryos, the mesoderm forms between the ectoderm (outer layer) and endoderm (inner layer).

3. Three distinct germ layers are formed: All these embryos undergo gastrulation to form three distinct germ layers - the ectoderm, mesoderm, and endoderm. These layers later develop into different tissues and organs in the organism.

The features like Blastocoel, Dorsal lip, Primitive streak, Spherical embryo, and Yolk may not be common to all these embryos as they are specific to certain types of embryos. For example, the blastocoel is a feature of blastula stage, not gastrula. The dorsal lip and primitive streak are features of amphibian and bird/mammal gastrulation respectively. The spherical embryo and yolk are also not common features.