Two copies of a duplicated chromosome attached to each other by proteins at the centromere.Group of answer choicessister chromatidschromatin

The correct answer is sister chromatids.

Explanation

Sister chromatids are the identical copies of a chromosome that are formed during DNA replication. They are joined together at a region called the centromere. This structure is crucial during cell division (mitosis and meiosis), where sister chromatids are separated and distributed to daughter cells, ensuring each new cell receives the correct number of chromosomes.

In contrast, chromatin refers to the complex of DNA and proteins in the nucleus of a cell, which condenses to form chromosomes during cell division. Therefore, the phrase "two copies of a duplicated chromosome attached to each other by proteins at the centromere" specifically describes sister chromatids.