| Answer | Crossword Clue |
|---|---|
| ISOTOPE | One of an element's closely related atoms |
| outcrossed | Breed (an animal or plant) with one not closely related |
| outcrossing | Breed (an animal or plant) with one not closely related |
| outcross | Breed (an animal or plant) with one not closely related |
| outcrosses | Breed (an animal or plant) with one not closely related |
| urushiol | a mixture of catechol derivatives with saturated or unsaturated side chains of 15 or 17 carbon atoms that is an oily toxic irritant principle present in poison ivy and some related plants (genus Rhus) and in lacquers derived from such plants |
