Chromosomes Answers

130

Nondisjunction is the failure of sister chromatids or homologous chromosomes to separate properly during cell division, such as meiosis. This results in gametes that have an abnormal number of chromosomes (either an extra chromosome or a missing one). When such a gamete is involved in fertilization, the resulting zygote has an irregular number of chromosomes, a condition known as aneuploidy. Examples of aneuploidy include trisomy, which is having an extra chromosome, and monosomy, which is missing a chromosome.

2000

Some genetic disorders found on chromosome 11 include sickle cell anemia, beta-thalassemia, Wilms tumor, aniridia, and albinism.

Genetic disorders associated with chromosome 17 include BRCA1 breast cancer, neurofibromatosis type 1, Alexander disease, Charcot-Marie-Tooth disease, and Canavan disease.

Sickle cell anemia is a blood disorder where red blood cells are misshapen, making it difficult for oxygen to be transported throughout the body. Wilms tumor is a rare form of kidney cancer that primarily affects children. Aniridia is a condition where the iris of the eye is missing or underdeveloped.

The BRCA1 gene is a tumor suppressor gene; mutations in it significantly increase a person's risk for breast and ovarian cancer. Neurofibromatosis type 1 is a disorder that causes tumors to grow on nerve tissue and can cause skin pigment changes.