1. why is it important for the centromeres to line up on the equator of the cell
ID: 64154 • Letter: 1
Question
1. why is it important for the centromeres to line up on the equator of the cell during mitosis? how should the chromosome be aligned in relation to the centriole a at the opposite poles of the cell?
2. what would happen of the kinetochore spindle fibers did not capture and attach to the kinetochores located at the centromere of a chromosome?
3. explain the structural differences between chromatin and chromosomes?
4. do all the cells of a multicellular organism contain the same genetic information? justify the answer with describing how the cells arose.
Explanation / Answer
1) Centromere aligns themselves in the equatorial plane mainly because of the pulling effect of the microtubules. The centromere keeps the sister chromatids intact enabling the alignment of the chromosomes in an equatorial plane.
The chromosomes would be aligned in a perpendicular mode with relation to the spindle fibers and centrioles in the opposite side of the cell.
2) Kinetochores are those protein structures on the genetic material to which the spindle fibers attach themselves during cell division. During the metaphase and during anaphase, the pulling of the sister chromatids towards the poles are as a result of the action of the spindle fibers that are attached to the kinetochores. Hence, if the spindle fibers are not attached to the kinetochores then the separation of sister chromatids during cell cycle will not happen and would lead to syndromes.
3) Both chromatin and chromosomes are structures exhibited by the genetic materials, where, the chromatin are more loosely packed structure, while, the chromosomes are highly tightly packed structure.
4) Yes. The genetic material of a multicellular organism does not change. This is because a multicellular organism would have been developed from a single cell (zygote). Since, the zygote undergoes only mitotic division where the crossing over of genetic material does not take place (unlike meiosis), the genetic material of a multicellular organism would be the same in all its cells. It is only the expression of the gene present in a cell that is organized to form a particular organ differs. The cells belonging to one organ expresses specific genes that are different from the cells that are found in a different organ.
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