The three primary germ layers in birds and mammals form from cells that migrate through the Blank______.Multiple choice question.neural crestprimitive streakblastocoel cavitylateral fold

In birds, cells that migrate through the primitive streak into the interior of the embryo become which of the following germ layers?Multiple choice question.Endoderm or mesodermEctoderm or endodermMesoderm or ectoderm

Multiple Choice QuestionThe extraembryonic membrane that is the first site of blood cell formation in mammals is the Blank______.Multiple choice question.allantoisyolk sacamnionchorion

The blastula in birds consists of a cap of cells, the Blank______, atop the yolk.Multiple choice question.blastodiscblastocoelblastomereblastocyst

A mammalian egg undergoes Blank______ cleavage, forming a structure called a Blank______.Multiple choice question.meroblastic; blastocystmeroblastic; blastodischoloblastic; blastocystholoblastic; blastodisc

What term best describes animals with three embryonic germ layers?Multiple choice question.EndoblasticEctoblasticTriploblasticDiploblastic