Final answer:
The centromeres are the specialized DNA sequences that provide an attachment point for the segregation of duplicated chromosomes, playing a critical role during cell division.
Step-by-step explanation:
The specialized DNA sequences which provide an attachment point for the segregation of duplicated chromosomes are known as centromeres. During mitosis and meiosis, the centromeres play a crucial role by attaching duplicated chromosomes to the spindle fibers via a structure called the kinetochore, which is crucial for the proper segregation of chromosomes into daughter cells. The identical copies of chromatin that are held together by cohesin at the centromere are called sister chromatids, and they are separated from each other during anaphase.
Additionally, during prophase I in meiosis, the chromosomes are paired up and the cohesin proteins are responsible for maintaining their alignment. The nuclear envelope breaks down at the start of mitosis to allow the spindle apparatus to access and interact with the chromosomes. Moreover, the spindle fibers made of microtubules attach to the centromeres during mitosis to facilitate the movement of chromosomes.
It's important to contrast this role of centromeres with other parts of the chromosome, such as telomeres, which protect the ends of chromosomes, and DNA replication origins, which are the starting points for DNA synthesis.