Abastost is a group of cells that forms after a human egg is fertilized. The bastos consists of two types of cells. Some of these cells will become the
placenta. What do the other cells develop into?

A Theskeletal and muscular systems of the fetus
B- Themenious and endocrine systems of the fetus
C. All of the cells of a developing fetus
D. The umbilical cord linking the fetus and mother

The images show two species of tree frogs in a particular region. the gray tree frogs are adapted to the trees of the woodlands, while the green tree frogs can survive in woodlands or grasslands. the gray frog was abundant in the woodlands. because of climatic changes, most of the trees in the region died, and the woodlands changed to grasslands. in such a case, the . the gray tree frog is closely related to the green tree frog genetically, but they have different mating calls. this suggests that speciation occurred because of .