| 1 | There was a sudden change in the weather. | |
| 2 | Those mutations happen all the time. | |
| 3 | Virus from one of the patients shows mutations at the receptor-binding site. | |
| 4 | Now they can and that helps keep the mutation in circulation. | |
| 5 | An individual, an organism, or a new genetic character arising or resulting from mutation. |