Match the following terms and definitions. 1. a type of egg or sac filled with fluid to support an embryo endothermic 2. a sac-like ball of cells surrounding a fluid-filled cavity that develops after the morula in embryonic development amniotic 3. animals having a dorsal notochord and nerve cord at some point in its development morula 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 blastula 5. organisms that regulate body temperature from outside surroundings; has a fluctuating temperature ectothermic 6. organisms that regulate body temperature internally; maintains a constant temperature chordates 7. formation of a three-layered embryo, following the blastula, in embryonic development gastrula 8. a ball of cells that develop during the beginning stage of embryonic development deuterostomes p ease me @ ag230349