Final answer:
The H3 histone variant present in the yeast centromere is Cse4p, which is essential for centromere function and proper chromosome segregation during cell division.
Step-by-step explanation:
The H3 histone variant present in the yeast centromere is called Cse4p. In eukaryotic cells, the centromere is a region of DNA where the kinetochore forms and where spindle fibers attach during cell division. The Cse4p is a variant of histone H3 that plays a critical role in ensuring proper segregation of chromosomes during cell division. Unlike the core histone H3, Cse4p is specifically localized to centromeric DNA in yeast and functions analogously to the centromere-specific histone H3 variant CENP-A in higher eukaryotes. Presence of Cse4p is essential for the establishment and maintenance of a functional centromere.