Match the following terms and definitions.

1. a type of egg or sac filled with fluid to support an embryo

2. a sac-like ball of cells surrounding a fluid-filled cavity that develops after the morula in embryonic development

3. animals having a dorsal notochord and nerve cord at some point in its development

4. organisms that form by radial cleavage and develop an anus from the first indentation of the gastrula stage of embryonic development; includes echinoderms, chordates, and vertebrates

5. organisms that regulate body temperature from outside surroundings; has a fluctuating temperature

6. organisms that regulate body temperature internally; maintains a constant temperature

7. formation of a three-layered embryo, following the blastula, in embryonic development

8. a ball of cells that develop during the beginning stage of embryonic development

a. deuterostomes
b. ectothermic
c. gastrula
d. endothermic
e. blastula
f. chordates
g. amniotic
h. morula