Cells in an embryo’s _______________ will later form muscle, bones, and the circulatory system.

Most of the _________ in vertebrate embryos are replaced by bones in adults.Ligaments Cartilages TendonsMuscles

mammals, embryonic cells form an inner cell mass that will become the body of the embryo and a layer of surrounding cells that will become the chorionic membrane and placenta. What are these surrounding cells called?Group of answer choicesyolktrophoblastblastocoelblastodisc

The ____________is the organ that holds the fetus as it grows.

How do cells of an embryo get inside during gastrulation?Multiple ChoiceCells crawl and change shape.The fertilization envelope punches in the blastopore.Muscle contractions of the uterus punch in the blastopore.Enzymes dissolve a hole in the blastocyst.

- In embryonic life blood cells are formed in the