6. Dominant inheritance.
| a. | is associated with a 1:4 risk of transmission of the condition. | |
| b. | is the mode of inheritance of spina bifida. | |
| c. | is the mode of inheritance of Huntington's chorea. | |
| d. | is the mode of inheritance of phenylketonuria. | |
| e. | is the mode of inheritance of Tay-Sachs disease. |