Final answer:
The Ced-9 mutant affects embryogenesis, causing all cells to die. Ced-9 is a gene that regulates apoptosis signaling, and when it is mutant, programmed cell death is inhibited.
Step-by-step explanation:
In this case, the Ced-9 mutant affects embryogenesis, causing all cells to die. Ced-9 is a gene that plays a crucial role in regulating apoptosis, which is the process of programmed cell death. When Ced-9 is mutant, it prevents the initiation of apoptosis signaling, leading to the survival of cells that should normally undergo programmed cell death.