Question

Which of the three cell layers in animal embryos gives rise to the muscles ad the circulatory, reproductive, and excretory systems?

Answer 1

Mesoderm.

Explanation:

The mesoderm germ layer forms in the embryo of triploblastic animals.
Through cell signalling cascades and interactions with the ectodermal and endodermal cells , the mesodermal cells begin the process of differentiation.
The mesoderm forms :
- smooth and striated muscles
- circulatory system
- genitourinary system
- connective tissue
- notochord
- bone
- cartilage
- adipose tissue
- lymphatic system
- dermis
- serous membranes