Friday, January 4. Bell Work:

Transcription

1 Friday, January 4 Bell Work: Red green colorblindness is an X linked trait and is recessive. A male who is normal marries a woman who is a carrier, what is the phenotypic ratio of their offspring? 1

2 Genetic Disorder An abnormal condition that a person inherits through genes or chromosomes caused by mutations or changes in a person s DNA Mutations can occur during meiosis or can be passed from parent to child through an already existing mutation. Mutation a sudden change in characteristics 2

3 What s the difference between a treatment and a cure? A cure eliminates the symptoms and the disease. A treatment controls the symptoms without eliminating the disease. 3

4 Cystic Fibrosis A genetic disorder that causes thick mucus to build up in a person s lungs and intestinesmaking it hard to breathe. Bacteria grow in mucus and can cause infection/lung damage Mucus makes digestion in intestines difficult Affects the whole body, oftentimes leads to an early death Avg. life span is 37.4 years Other symptoms include: poor growth and poor weight gain despite a normal food intake, accumulation of thick, sticky mucus, frequent chest infections and coughing, and sinus infections. 4

5 Can be diagnosed using a genetic test, even before birth Recessive Most common in people from Northern Europe Currently no cure exists but treatments exists for lung infections: medications, breathing treatments Sometimes lung transplants are also necessary physical therapy is available to help break down the mucus Important for them to stay active 5

6 Sickle Cell Anemia Genetic disorder that affects the blood Shape of cells always serves a purpose RBC are usually disc shape so that they can move easily through the vessels in your body Sickle cell anemia patients have sickle or half moon shape RBC causing them to get stuck in narrow blood vessels. 6

7 The mutation that causes the disorder affects the production of an important protein called hemoglobin Carries oxygen to all parts of your body Oxygen levels are very low in people who have sickle cell anemia. It is a co dominant allele with the normal one. African ancestry is most common place for disease (1 in 12 are carriers). Pain, weakness, and lack of oxygen are all symptoms. A person with two sickle cell traits will have the disease, person with one allele will be a carrier and produce ½ sickle cells, ½ normal and generally they do not have any health issues. No cure but given drugs to help with pain and prevent blockage in blood vessels. 7

8 Hemophilia Genetic disorder in which a person s blood clots very slowly or not at all they lack the proteins necessary for clotting Could bleed to death from a minor cut or scrape Doesn t bleed at a faster rate, just for longer periods of time Recessive allele on x chromosome (sex linked) more common in males than females Can lead normal lives but advised to avoid contact sports and other activities that could cause internal injuries 8

9 Bell Work: Monday, January 7 What is the cause of hemophilia? How is it inherited? 9

10 Huntington s Disease Lethal genetic disorder by a rare dominant allele in which certain parts of the brain start to break down. This causes uncontrolled movements, emotional disturbance, lack of concentration, eventually they have trouble feeding themselves and swallowing Onset doesn t usually occur until years old there is no way to stop or reverse the course of HD Medications do exist to help with muscle control and emotional problems 10

11 Inheritance of Huntington s We now have a test that can be done to determine whether or not you have the allele The disease runs in families passed from parent to child through a mutation in the normal gene. Each child of an HD parent has a chance of inheriting the HD gene. If a child does not inherit the HD gene, he or she will not develop the disease and cannot pass it to subsequent generations 11

12 Down Syndrome A genetic disorder in which a person s cells have an extra copy of chromosome 21 Can see this by doing an amniocentesis or looking at baby when born An error occurs during meiosis chromosomes fail to separate Occurs when mothers are older when they have kids People with this genetic disorder have a distinctive physical appearance (flattened face, upward slanted eyes) and some degree of mental retardation, heart defects are also common but most can be treated, infertile. Physical genetic limitations of Down syndrome cannot be overcome, but education and proper care will improve quality of life. 12

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