There are currently 8,614,790 lane miles of road in the lower 48 states. The average width of a highway lane is 11 feet. This means roads cover 17,947 square miles of land, or just six-tenths of 1 percent of the total land area of the contiguous 48 states.
Role of the centrosome in cell cycle progression. Centrosomes are associated with the nuclear membrane during prophase of the cell cycle. In mitosis the nuclear membrane breaks down and the centrosome nucleated microtubules (parts of the cytoskeleton) can interact with the chromosomes to build the mitotic spindle.he centrosome replicates during the S phase of the cell cycle. During the prophase in the process of cell division called mitosis, the centrosomes migrate to opposite poles of the cell. The mitotic spindle then forms between the two centrosomes. Upon division, each daughter cell receives one centrosome.
The other major function of the centromere is attaching the microtubules in the mitotic spindle. In this function, the centromere directs the formation of the kinetochore, which is a special protein structure that attaches to the microtubules in the mitotic spindle. On each chromatid, the kinetochore forms at the centromere region of the DNA.