The zona pellucida is important in mammals because it...

Which of the following correctly lists the germ layers of an embryo? A exoderm, mesoderm, underderm. O B. R ectoderm, midderm, underderm. OC. c exoderm, midderm, entoderm. ectoderm, mesoderm, endoderm. OD. O E. Zygoderm, diploderm, metaderm.

In mammals the AVE… a. All of the options provided here are true. b. helps position the primitive streak. c. secretes signals which inhibit Nodal and Wnt signaling. d. is formed via mechanical stress of the uterine wall on the embryo.

Which of the following correctly identifies the different phases of human development? Select one: a. Weeks 1 to 8 are called the fetal development, and weeks 9 to 39 are called the embryonic development. b. Weeks 1 to 8 are called the embryonic development, and weeks 9 to 39 are called the fetal development. c. The 1st trimester is fertilization and mitosis, and the 2nd and 3rd trimesters involve differentiation. d. The 1st trimester is called the embryonic development, the 2nd trimester is called the fetal development, and the 3rd trimester is when the baby grows to gain more weight.

Compare and contrast the development of a fetus and rabbit. Explain what occurs in each stage.  Try to explain what happens at each stage for your animal and the human.

Which of the following statements regarding the formation of human twins is INCORRECT? a. Nearly all identical twins form before the 9th day following fertilization. b. Identical twins share an umbilical cord. c. Fraternal twins form after two eggs become fertilized. d. Identical twins form after two eggs become fertilized.