1. Specify the location and function of the centromere.
The centromere is a region of a eukaryotic chromosome where the kinetochore is assembled thus; it is the site where spindle fibers of the mitotic spindle attach to the chromosome during mitosis. (Centromeres are highly complex chromosomal substructures involved in essential aspects of chromosome transmission during cell division.)
a) Name the three types of chromosomes found in human cells based on the location of the centromere.
The centromeres can be found in the middle of the chromosome (median), near one end (acrocentric) or in between these first two (submedian). Chromosomes are arranged into seven groups based on size and centromere location.
Group A: chromosomes 1-3 are largest with median centromere;
Group B: chromosomes 4-5 are large with submedian centromere; Group C: chromosomes 6-12 are medium sized with submedian centromere;
Group D: chromosomes 13-15 are medium sized with acrocentric centromere;
Group E: chromosomes 16-18 are short with median or submedian centromere;
Group F: chromosomes 19-20 are short with median centromere;
Group G: chromosomes 21-22 are very short with acrocentric centromere; chromosome X is similar to group C and Y is similar to group G.
b) Which type is not found in human cell?
The fourth type is Telocentric where the centromere is at the end of the chormosome so that the chromosome appears to be one armed under a microscope. The difference ...