Chromosome Mutations or Chromosome Aberrations
Changes in the total number of chromosome, such as a deletion or rearrangement
Variations in chromosome number. When an organism gains or loses one ore more chromosomes and has other than an exact multiple of the haploid set
Chromosomal variation arises from nondisjunction, where chromosomes or chromatids fail to disjoin and move to opposite poles during Meiosis I or II
2n+1 Chromosomes. Often lethal for autosomes, but not sex chromosomes. Three copies of one chromosome are present so pairings are irregular.
An unpaired chromosome, can be present along with a bivalent instead of a trivalent. When 3 chromosomes aren't synapsed, instead 2 are and 1 is left unpaired.
Amniocentesis or Chorionic Villus Sampling (CVS)
Testings for women who become pregnant late in their reproductive years
The addition of one or more sets of chromosomes identical to the haploid complement of the same species
The combination of chromosome sets from different species as a consequence of interspecific matings
The condition in which only certain cells in an otherwise diploid organism are polyploid
Chromosome breaks in one or more places and a portion if it is lost, the missing piece.
Results form a segmental deletion of a small terminal portion of the short arm of chromosome 5
Arise as the result of unequal crossing over during meiosis or through a replication error prior to meiosis
Involves a rearrangement of the linear gene sequence rather than the loss of genetic information. Segment turned 180 degrees in a chromosome, requires two breaks and reinsertion of the inverted segment. May arise from chromosomal looping
Includes centromere, does change the relative lengths of the two arms of a chromosome
Paracentric inversion crossover
One recombinant chromatid is dicentric (two centromeres) and one is acentric (lacking a centromere)
Involves the exchange of segments between two nonhomologous chromosomes. Unusual synapsis