Microbiology In apoptosis, Apaf-1 is activated by release of which of the following substance from the mitochondria? A Bcl - 2 B Bax C Bcl - Xl D Cytochrome C 💡 Explanation In apoptosis, Apaf-1 is activated by release of which of the following substance from the mitochondria? ✓ Correct Answer: D. Cytochrome C