Human Karyotyping (Biology) - Lab Report Example

Any deviation in the normal pattern could be ruled out as a change that affects health and development of the individual. It is evident that human cells normally contain 23 pairs of chromosomes. Hypothesis: If there is an increase or decrease in the number of chromosomes, the process is called aneuploidy; it directly affects the development of the organism. These changes occur as a result of non disjunction of chromosomes during the process of meiosis. As a result one of the daughter cells receives either extra or insufficient chromosomes.

Variables: The common form of aneuploidy is trisomy, which implies the presence of three copies of the chromosome in cells in place of normal two copies. In Klinefelter’s Syndrome where the sex chromosome is present in extra copy resulting in XXY, where as if the trisomy occurs in autosome like in the case of Down Syndrome trisomy of 21st chromosome occur and if this trisomy occur in 13th chromosome then it results in Trisomy 13 Syndrome resulting in cell with 47 chromosomes instead of usual 46.

Methods: Cut the homologous chromosomes. Arrange then on construction paper in descending order of their size. Glue them when arranged as in the figure A. any additional chromosome is found match with its homologue to find out which chromosome is having additional copy. Arrange all the pairs of chromosomes with shorter end towards top and longer one towards the bottom. Mark them with the marker pen; rule out the genetic condition of the Karyotype. Raw data: chromosomes condense during the process of cell division and are therefore visible under light microscope.

In Karyotype cells are stained with Giemsa dye. Dark and light band pattern is observed. Metacentric chromosomes have centromere in the center or near the central part of the chromosome. Acrocentric: the centromere is near the end of the chromosome. Telocentric: centromere is terminally located. Chromosomes