1) The process of fertilization produces a/an:

A) embryo.

B) blastula.

C) morula.

D) gastrula.

E) zygote.

2) The phase during which embryonic cells arrange themselves into three layers is called:

A) cleavage.

B) gastrulation.

C) organogenesis.

D) fertilization.

E) induction.

3) A difference between a morula and a blastula is that the:

A) morula is a solid ball of tightly packed cells, whereas the blastula has a cavity in the center.

B) blastula has fewer cells than the morula.

C) morula has a hollow center, but the blastula doesn’t.

D) morula is a well-developed embryo, and the blastula is an earlier stage of development.

4) If an organism is missing the outer layer of skin upon birth, which of the following might be the cause?

A) improper development of the mesoderm

B) improper development of the endoderm

C) improper development of the ectoderm

D) improper development of the endoderm and the mesoderm

5) Which characteristic is typical of the vegetal pole of an embryo?

A) The vegetal pole is composed of a single, large cell.

B) The vegetal pole is always hollow.

C) The vegetal pole contains relatively less yolk.

D) The vegetal pole has a relatively greater proportion of yolk.

E) The vegetal pole is the site of the development of the mouth.

6) Which of the following happens first in vertebrate development?

A) development of the neural plate

B) development of the neural crest

C) development of the neural tube

D) development of the notochord

7) Which is true regarding somites in an embryo?

A) Somites will become vertebrae.

B) Somites are found inside the notochord.

C) Somites will form the skull.

D) Somites will form the lungs.

8) In sea urchin development, the archenteron becomes the:

A) ectoderm.

B) endoderm.

C) digestive tube.

D) lungs.

9) Of the choices listed, the first event that occurs during embryonic development is:

A) germ layer formation.

B) blastula formation.

C) organogenesis.

D) cleavage.

10) Which of the following is a morula?

A) a fertilized egg

B) the group of cells that form the archenteron

C) a tightly packed ball of early embryonic cells

D) a hollow sphere of cells