CELL DIVISION Atypical or Abnormal Cell Division

Mitosis Gone Awry Mutations are changes in the molecular structure of DNA that ultimately creates diversity Carcinogens, radiation viruses and other factors can all cause mutations. Mutations in somatic cells aren’t passed to offspring Breast cancer cells dividing (3 days time lapse)

There are two different types of mutation: A) Gene Mutations – A new alleles for a trait suddenly appears on the chromosome that carries the gene

Damage to Chromosome Structure Large scale mutations that damage chromosome structure can occur when something unusual happens during crossing over. Translocation – the transfer of a chromosome segment to a non- homologous chromosome. Deletion - occurs when a chromosome segment breaks off, resulting in the loss of some genes Duplication – occurs when part of a chromosome is repeated Inversion – occurs when a piece of a chromosome is rotated so that the order of genes in the segment is reversed.

Atypical Meiosis NONDISJUNCTION – the uneven separation of homologous chromosomes during Anaphase.

Mutations in gametes Mutations in meiosis are inherited by offspring though no disorder was evident in the parent By age 42, 90% of a woman’s eggs are chromosomally abnormal. Thus, at age eighteen, 1:2,000 live births results in Down Syndrome. By age 42 that rises to 1:25

Trisomy 21 Down Syndrome – there is an extra chromosome in either the egg or sperm making 47 in the zygote

Genetic Screening Amniocentesis – withdraw fluid and cells from the amniotic sac surrounding the fetus to look at chromosomal abnormalities ocentesis.htm

Trisomy 8,9,13,16,18 March is Trisomy Awareness month. I photographed this series of portraits at the SOFT (Support for Families with Trisomy 18, 13 and Related Disorders) conference in Roanoke, Virginia during July I am trying to raise awareness that while only 10% of these kids survive their first year the ones that do live a rich life. Expectant parents are often told that Trisomy is incompatible with life and I am trying to share their unique beauty through these digital images. These children and young adults do not pose for photographs but can be captured being themselves, living in the moment. Most are non-verbal so I see it as an honor to help tell their stories visually.