Final answer:
A nucleosome core contains 146 nucleotide base pairs wrapped around a histone octamer. This is apart from the 'linker' DNA which connects one nucleosome to another and is not part of the nucleosome core itself.
Step-by-step explanation:
The question refers to the structure of a nucleosome, which is a fundamental subunit of chromatin, a complex of DNA and protein found in eukaryotic cells. A nucleosome consists of a segment of DNA wound in sequence around eight histone protein cores. Thanks to significant research, including the work of Roger Kornberg, we know that the nucleotide base pairs wrapped around the histone octamer in a single nucleosome is 146 base pairs long. Additionally, this DNA-histone complex is typically connected to another nucleosome by a stretch of 'linker' DNA, which varies in length but is approximately 54 base pairs long. However, the nucleosome core itself strictly contains 146 nucleotide bases.
Therefore, the correct answer to the question, 'How many nucleotide bases in a nucleosome core?' is A) 146.