An adaptation-----------------------
The Type O blood group is commonly called as universal donor because any blood group can receive the O blood group. The blood group O has no antigen. Due to the absence of antigen it doesn't agglutinate when come in contact with other blood groups in the plasma.
The agglutination reaction happens when opposite antigen and antibody reacts with each other. e.g.- Blood group A contains antigen A and antibody b and the blood group B contains antigen B and antibody a. Agglutination reaction occurs when the antigen A reacts with antibody a. As O blood group has no antigen, agglutination reaction doesn't occur.
Answer:
a structure composed of several proteins that associate with the centromere region of a chromosome and that can bind to spindle microtubules
Explanation:
Kinetochores have vvery important role in the cell division-mitosis.
During the metaphase of mitosis, spindle fibers attach to kinetochores. Some of the microtubules bind to kinetochore (kinetochore microtubules) while other don’t: they connect with the microtubules from the opposite pole, stabilizing the spindle.
During the anaphase, kinetochore microtubules pull chromosomes toward poles, helping the sister chromatids separate from each other.