Fertilization and Early Embryonic Development

Review Questions

Which of the following is false?

  1. The endoderm, mesoderm, ectoderm are germ layers.
  2. The trophoblast is a germ layer.
  3. The inner cell mass is a source of embryonic stem cells.
  4. The blastula is often a hollow ball of cells.

Hint:

B

During cleavage, the mass of cells:

  1. increases
  2. decreases
  3. doubles with every cell division
  4. does not change significantly

Hint:

D