CEN X is a proper noun that refers to a protein complex involved in chromosome segregation during cell division. The correct spelling of CEN X is "sɛn ɛks," which is represented in IPA phonetic transcription. The "sɛn" part is pronounced like "sen," with an open "e" sound, and the "ɛks" part is pronounced like "eks." Understanding the correct spelling and pronunciation of scientific terms like CEN X is important for effective communication in the field of biology.