Final answer:
Spindles are essential for segregating chromosomes during mitosis, attaching to chromatids through kinetochores and pulling them apart. Centrioles in animal cells help in spindle fiber organization. Skipping metaphase can cause improper chromosome separation, leading to genetic abnormalities in daughter cells.
Step-by-step explanation:
Functions of Spindles and Centrioles during Mitosis
Spindles perform a critical role during mitosis by ensuring that chromosomes are evenly divided and separated between the two daughter cells. During metaphase, spindle fibers attach to the kinetochores of chromosomes, which are located at the centromere of each sister chromatid. When cells enter anaphase, these spindle fibers pull the sister chromatids apart to opposite poles of the cell, ensuring that each new cell will receive an identical set of chromosomes.
Centrioles, which are specific to animal cells, are involved in the organization and assembly of spindle fibers. As part of the centrosome, centrioles help nucleate and anchor the microtubules that will form the mitotic spindle. The correct arrangement and functionality of these spindles are crucial for accurate and equal distribution of chromosomes during cell division, ensuring that each daughter cell is genetically identical to the parent cell.
If a cell were to skip metaphase, the sister chromatids would not properly align at the cell's equator, leading to unequal separation and potentially resulting in daughter cells with abnormal numbers of chromosomes, a condition known as aneuploidy. During cytokinesis in animal cells, a contractile ring forms at the site of the metaphase plate, constricting and eventually dividing the cell into two separate cells, each with its own nucleus and set of chromosomes.