Chapter 3 Pathology Questions

Chapter 3 Review Questions 1. What is meant by the following terms Homologous chromosomes- A matched pair of chromosomes, one derived from each pargonnt. Both members of the pair argon resembling in size, shape, and appearance, except for depend upon chromosomes. Autosomes- The general term for chromosomes other than the sex chromosomes. Sex chromosome- The X and Y chromosomes that determine genetic sex. Barr body- The inactivated X chromosome that appears as a small, dense mass of chromatin attached to the nuclear tissue layer of somatic electric stalls.This building can be identified in the cells of a normal female and is called a sex chromatin body or Barr body after the man who first described it. Gene- Are segments of desoxyribonucleic acid chains that determine some property of the cell and ar the primary units of inheritance. Sometimes, they atomic number 18 described as being arranged along the chromosome give care beads on a string. Gametogenesis- A specialized type of cell subdivision that occurs during the development of the eggs (ova) and spermatozoan. The development of mature eggs and sperm from precursor cells.Centrosome- A small region of cytoplasm adjacent to the centre that contains the centrioles and serves to electronic organize microtubules. 2. How does the process of mitosis compare with meiosis? In mitosis, each of the 2 new cells (called the daughter cells) resulting from the cell division receives the same number of chromosomes that were contri simplye in the precursor cell (called the parent cell). In meiosis, the number of chromosomes is lessen so that the daughter cells receive only half of the chromosomes possessed by the parent cell. This process is not completed until fertilized by the sperm. . What are the differences surrounded by spermatogenesis and oogenesis? First, four spermatozoa are produced from each precursor cell in spermatogenesis, but only one ovum is formed from each precursor cell in oogenesis. The ot her three daughter cells derived from the meiotic divisions are toss out as polar bodies. Second, spermatogenesis occurs continually and is carried through to complation in about 2 months. Consequently, seminal fluid always contains relatively fresh sperm. In contrast, the oocytes are not produced continually.All of the oocytes present in the ovary were formed before birth and give birth remained in a prolonged prophase of the first meiotic division from foetal life until they are ovulated. 4. What is a chromosome karyotype? How is it obtained? How is it used? A chromosome karyotype is an arrangement of chromosomes from a single cell arrangement in pairs in descending shape according to size of the chromosomes and the positions of the centromeres. A chromosome karyotype is obtained by culturing cells in a fitting medium. Usually, human telephone line is used as a source of cells for these studies the blood lymphocytes can be induced to undergo mitotic division.Certain chemical s are added to stop the mitotic division after the chromosomes have become separate and distinct, and consequently , many cells arrested in mitosis accumulate in the culture medium. Additional methods are employed to elbow grease swelling of the cells, which are thusly prepared, and the chromosomes can be examined. The chromosomes are then arranged according to their size, the location of the centromere, the relative lengths of the chromatids that extend outward from the centromere, and the recitation of light and dark bands along the chromosomes.Then the separated chromosome from one cell are photographed and arranged into a karyotype. The presence of abnormalities in chromosome number or structure can be detected this way. 5. What is the MHC? What is its function? What is its relationship to disease strength? The MHC is the major histocompatibility complex. The antigens present on cells are determined by a cluster of genes on chromosome 6. This group of genes, which was first determined in lab animals in connection with transplantationation experiments, is called the MHC.Originally, MHC proteins were considered of interest only with respect to organ transplantation because transplantation of cells containing MHC proteins different from those of the transplant recipient was followed by rejection of the transplant unless the immune system was suppressed. They take part in generating immune responses to distant antigens of all types. The interaction of the HLA antigens with the various cells of the immune system is considered in the word of honor on immunity, hypersensitivity, allergy, and autoimmune diseases. 6.What is a haplotype? How are haplotypes inherited by churlren from their parents? What are the chances that two children will have the same haplotype? A haplotype is a perplex of HLA genes on one chromosome and is transmitted as a unit. Each child receives one of two possible haplotypes from each parent. Because of the way in which chromosomes are transmitted from parent to child, the child has any of four different combinations of HLA haplotypes. in that respect is one in four probability that two children will some(prenominal) possess the same pair of HLA haplotypes.