Genetic Disorders Ch. 5 section 2

Causes Genetic Disorder: an abnormal condition that a person inherits through genes or chromosomes. Some are caused by mutations in DNA. Others by the changes in structure or Number of chromosomes.

Cystic Fibrosis The body produces abnormally thick mucus in the lungs and the intestines. Mucus makes it hard to breath. The recessive allele is a result of a mutation in which 3 bases are removed.

Sickle Cell Disease Affects the hemoglobin in red blood cells that carry oxygen. When oxygen levels are low the red blood cell has a sickle shape. Blot clots are common with this disease.

Hemophilia Disorder where a person’s blood clots very slowly. Occurs more in males than females. People bleed a lot just from a small cut.

Downs Syndrome A person’s cells carry an extra copy of chromosome 21. Instead of a pair of chromosomes they have 3 in the 21st set. People with DS have a degree of mental retardation and heart defect are also common.

Pedigrees An important tool that geneticists use to trace inheritance of traits in humans. Chart or “family tree” that track which family member has a particular trait.

Karyotypes Picture of all the chromosomes in a cell. Can help reveal if a person has the correct number of chromosomes in his or her cells.

Dealing with genetic disorders People with disorders face serious challenges. Medical care and treatments can help people with some of these disorders. Most genetic disorders do not prevent people from living active and productive lives.

CH. 5 section 3 Selective Breeding: selecting organisms with desired traits to be parents of the next generation. Inbreeding: crossing 2 individuals that have similar characteristics. (usually very similar) Hybridization: cross 2 genetically different individuals.

Cloning Can be used to produce offspring with desired traits. Clone: organism that has the exact same genes as the organism in which it was produced by. Researchers have cloned sheep and pigs.

Genetic Engineering Genes from one organism are transferred into the DNA of another. One type of Bacteria is genetically engineered to produce insulin that is used for people with Diabetes.

Gene Therapy Involves inserting copies of a gene directly into a person’s cells.

Concerns Long term effects are still in question. could cause health problems or environmental problems.

Human Genome project Genome: all the DNA in one cell of an organism. Goal is to identify the DNA sequence of every gene in the human genome. Humans contain at least 30,000 genes. Average gene has about 3,000 bases.