Final answer:
The H3 histone variant present in the yeast centromere is Cse4p (option B), which is equivalent to CENP-A in higher eukaryotes and is crucial for chromosome segregation during cell division.
Step-by-step explanation:
The H3 histone variant present in the yeast centromere is Cse4p. Histones are DNA binding proteins that play a critical role in the structure and function of chromatin. In yeast, Cse4p (also known as CENP-A in higher eukaryotes) is a specialized histone H3 variant that is incorporated into nucleosomes at the centromere. This variant is crucial for the proper segregation of chromosomes during cell division.
The DNA in eukaryotic cells is packaged into chromatin, with the basic unit being the nucleosome, which is composed of DNA wrapped around an octamer of histone proteins. During certain stages of the cell cycle, such as metaphase, chromatin becomes highly condensed, and the centromeres play a pivotal role in kinetochore formation and chromosome segregation.