| Name: | ball | 
|---|---|
| Synonyms: | yolk ball | 
| Definition: | The anterior round region of the yolk cell present after the yolk extension forms during the segmentation period. | 
| Ontology: | Anatomy Ontology [ZFA:0000006] | 
| Name: | nucleate erythrocyte | 
|---|---|
| Synonyms: | RBC, red blood cell | 
| Definition: | An erythrocyte having a nucleus. | 
| Ontology: | Anatomy Ontology [ZFA:0009256] |