The trisomic condition also is one of chromosomal imbalance and can result in abnormality or death. A Distribution of the percentage of chromosome 18 in five concentric equidistant nuclear shells. First of all, in plants, pollen cells are very sensitive to aneuploidy, and aneuploid pollen grains will generally be inviable.
Sex Chromosomes. This deactivated X chromosome can be seen as a small, dark-staining structure—the Barr body —in the cell nucleus. Please verify that you are not a robot. Creator: Zane. This online quiz contains 25 questions from a pool of over thereby allowing repeat use. Linked Data More info about Linked Data.
Write a review Rate this item: 1 2 3 4 5.
In contrast, the active X chromosome undergoes architectural changes as a function of increasing X copy number as measured by a decrease in size and an increase in circularity, which is indicative of chromatin compaction. In the normal life cycles of these insects, males develop parthenogenetically from unfertilized eggs.
B Number of Xist foci detected per nucleus in polyploid X nuclei.
One particularly satisfying one is shown by the genus Brassica, as illustrated in Figure New York: W. Hum Genet , 1—4. While the latter observation is explained by the well-established X-inactivation process used to compensate for the increased number of X chromosomes Lyon, ; Boumil and Lee, ; Willard, , the mechanism for the reduction of Y size is unknown.