Chromosomes+CC

Chapter 18.5 Chromosome Inheritance

o nondisjunction- occurs during meiosis 1when both members of a homologous pair go into the same daughter cell trisomy-one type of chromosome is present in three copies monosomy- one type of chromosome is present in one copy Barr body-in the normal XX females, one of the X's becomes a darkly staining mass of chromatin. Down Syndrome-an autosomal trisomy because they have three copies of chromosome 21 Turner Syndrome- an individual only has one chromosome, an X Klinefelter Syndrome- XXY, which means a male has an extra X chromosome so he may have some female traits (breasts) Poly-X Females- female has more than 2 X chromosomes and may have an extra barr body in the nucleus Jacobs Syndrome- XYY males which results from nondisjunction during spermatogenesis. o What are the two types of chromosomes and how many of each do we have in every cell? There is an X and Y chromosome that determine the sex and characteristics of an individual. A normal individual has 22 pairs of autosomes and two sex chromosomes. o Describe process that can change the normal number of chromosomes in a cell? Non disjunction is when both members of a homologous pair go into the same daughter cell or when the sister chromatids fail to separate and both daughter chromosomes go into the same gamete. o Name chromosome disorders due to an abnormal number of autosomal chromosomes. Down Syndrome, o Name chromosome disorders due to an abnormal number of sex chromosomes. Turner syndrome, klinefelter syndrome, Poly X females, jacobs syndrome
 * Changes in Chromosome Number

o Vocab: deletion-when an end chromosome breaks off or when two breaks lead to the loss of an internal segment duplication-a chromosomal segment that occurs more than once in the same chromosome inversion-a segment of a chromosome to another non homologous chromosome translocation-movement of a chromosome segment from one chromosome to another non homologous chromosome Williams syndrome- occurs when chromosome 7 looses an end piece Crit du Chat syndrome- chromosome 5 is missing an end piece Alagille sydnrome- affects the heart, liver, and other parts of the body. autosomal dominant problem Chronic myelogenous leukemia- form of leukemia because of an abnormal growth of predominantly myeloid cells in the bone marrow and in the blood Burkett lymphoma- cancer of the lymphatic system o Name chromosome deletion syndromes. williams syndrome, crit du chat syndrome, o Name chromosome translocation syndromes. alagille syndrome, cancers, myologenous leukemia, burkitt lymphoma
 * Changes in Chromosome Structure