Chromosomal Mutations

Mutations in Number
-Aneuploidy- an extra or missing chromosome
-There is Monosomy which is the lack of one chromosome, this can lead to Turner syndrome if it is in the sex chromosomes
-Disomy are two copies of chromosomes, which is natural in humans
-Trisomy which is three copies of chromosomes, this kind can lead to Down syndrome
-Tetrasomy/pentasomy which is four or five copies.
-This kind of mutation can also lead to miscarriages
Structural Mutations
-Deletions
    -When part of a chromosome is missing
    -Causes can be, unequal crossing over or breaking without rejoining
   - Small deletions are not fatal usually, unlike large ones which are. Medium deletions can result in human             disorders
-Duplications
   - A duplication of a region of a chromosome
   - It does not have any negative effects on the organism
   - It can help in evolution
-Translocations
   - The rearrangement of no homologous chromosomes
   - It can be reciprocal (an exchange of material) which is usually harmless or it can be Robertsonian (the fusion     of two chromosomes near the centromere, losing its short arms), this can cause cancer, infertility, and down     syndrome
  -  There are balanced ones, with an equal exchange of genetic material and unbalanced with an uneven exchange resulting in extra or missing genes -Invertions
    -The rearrangement in which a segment of chromosomes are reversed end to end
    -Paracentric- does not include the centromere and the break occurs only in one arm
    -Pericentric- includes the centromere and the break is in both arms
    -In most species it has no effect