| Label | Id | |
|---|---|---|
| notochord | http://purl.obolibrary.org/obo/MAT_0000281 | |
| occipital lobe | http://purl.obolibrary.org/obo/MAT_0000507 | |
| oesophagus | http://purl.obolibrary.org/obo/MAT_0000048 | |
| olfactory bulb | http://purl.obolibrary.org/obo/MAT_0000116 | |
| olfactory epithelium | http://purl.obolibrary.org/obo/MAT_0000445 | |
| olfactory lobe | http://purl.obolibrary.org/obo/MAT_0000116 | |
| olfactory pits | http://purl.obolibrary.org/obo/MAT_0000139 | |
| olfactory system | http://purl.obolibrary.org/obo/MAT_0000139 | |
| omatidium | http://purl.obolibrary.org/obo/MAT_0000143 | |
| oral cavity | http://purl.obolibrary.org/obo/MAT_0000038 | |
| oral region | http://purl.obolibrary.org/obo/MAT_0000038 | |
| organism subdivision | http://purl.obolibrary.org/obo/MAT_0000293 | |
| oropharynx | http://purl.obolibrary.org/obo/MAT_0000446 | |
| otic vesicle | http://purl.obolibrary.org/obo/MAT_0000138 | |
| outer ear | http://purl.obolibrary.org/obo/MAT_0000147 |