An error in meiosis or mitosis in which members of a pair of homologous chromosomes or a pair of sister chromatids fail to separate properly from each other.
A chromosomal aberration in which one or more chromosomes are present in extra copies or are deficient in number.
Referring to a diploid cell that has only one copy of a particular chromosome instead of the normal two.
Referring to a diploid cell that has three copies of a particular chromosome instead of the normal two.
A chromosomal alteration in which the organism possesses more than two complete chromosome sets. It is the result of an accident of cell division.
(1) A deficiency in a chromosome resulting from the loss of a fragment through breakage. (2) A mutational loss of one or more nucleotide pairs from a gene.
An aberration in chromosome structure due to fusion with a fragment from a homologous chromosome, such that a portion of a chromosome is duplicated.
An aberration in chromosome structure resulting from reattachment of a chromosomal fragment in a reverse orientation to the chromosome from which it originated.
(1) An aberration in chromosome structure resulting from attachment of a chromosomal fragment to a non-homologous chromosome. (2) During protein synthesis, the third stage in the elongation cycle, when the RNA carrying the growing polypeptide moves from the A site to the P site on the ribosome. (3) The transport of organic nutrients in the phloem of vascular plants.
A human genetic disease usu- ally caused by the presence of an extra chromosome 21; characterized by developmental delays and heart and other defects that are generally treatable or non-life-threatening.
A phenomenon in which expression of an allele in offspring depends on whether the allele is inherited from the male or female parent.