Phases or components
Your textbook describes two
sequential phases of interaction between organisms and their environments that
have existed since god's creative work began. Organisms interact with their
environments in different ways. Different organisms of a biological community cooperate
and compete for habitats and share the resources in that habitat.
Germ layer is a primary layer of cells found in the embryo. The three primary germ layers that generate most of the cells in the developing mammalian forelimb are ectoderm, mesoderm and endoderm.
Ectoderm forms the outer component of a mammalian body such as skin, hair, etc. Endoderm forms the inner layer that comprises of the linings of digestive system, lungs and thyroid. Mesoderm is the middle layer that forms the skeletal system, heart, etc.
Neural tube is generated by the inward folding of the ectoderm. This process is called neurulation. Ectoderm also forms neural crest.
<span>You can bolt it to wall studs.</span>
