what holds the sister chromatids together and attaches them to the spindle fibers
Kinetochore The kinetochore (/kɪˈnɛtəkɔər/, /-ˈniːtəkɔər/) is a protein structure on chromatids where the spindle fibers attach during cell division to pull sister chromatids apart.[1] Their proteins help to hold the sister chromatids together and also play a role in chromosome editing.[2]
Chromosome In eukaryotes, nuclear chromosomes are packaged by proteins into a condensed structure called chromatin. This allows the very long DNA molecules to fit into the cell nucleus. The structure of chromosomes and chromatin varies through the cell cycle. Chromosomes are even more condensed than chromatin and are an essential unit for cellular division. Chromosomes must be replicated, divided, and passed successfully to their daughter cells so as to ensure the genetic diversity and survival of their progeny. Chromosomes may exist as either duplicated or unduplicated. Unduplicated chromosomes are single double helixes, whereas duplicated chromosomes contain two identical copies (called chromatids or sister chromatids) joined by a centromere.
Nuclear membrane Exactly how the nuclear membrane reforms during telophase of mitosis is debated. Two theories exist[7]â€”
Seed Seeds are the product of the ripened ovule, after fertilization by pollen and some growth within the mother plant. The embryo is developed from the zygote and the seed coat from the integuments of the ovule.