Genetic disorders

1. Genetic disorders

2. I am learning to: explain inheritance of a range of genetic diseases and state their symptoms Know how cystic fibrosis is inherited using cross diagrams Describe symptoms of Cystic fibrosis and Huntington's diseases Draw genetic cross diagrams for the dominant disease Huntington's disease. Outcome: I draw genetic cross diagrams for Cystic fibrosis and Huntington's disease

3. Starter: • Disease of nervous system = Dominant • Disease of cell membranes /lungs = recessive Cystic fibrosis Huntington's

4. Cystic fibrosis • Cystic fibrosis is an inherited disease that particularly the lungs and digestive system. • In a person with cystic fibrosis, mucus is thicker than normal. This thick, sticky mucus can block the lungs and airways • People with cystic fibrosis need daily physiotherapy to help loosen the sticky mucus and Antibiotics help to treat and control lung infections • People with cystic fibrosis can have problems digesting food. Most take enzyme pills

5. Task 1: Cystic fibrosis • What is Cystic fibrosis and what organs does it mainly affect? • What treatment is required?

6. Task 2: inheriting Cystic Fibrosis • Caused by a recessive allele – c • A person with cystic fibrosis has the Genotype - cc • Carriers are Cc • Normal = CC • What is the chance of 2 carriers having a child with CF?

7. Task 3: inheriting Cystic Fibrosis • What is the chance of a homozygous recessive person and a normal person having a child with CF?

8. Huntingtons Disease • Huntingtons is an inherited disease that affects the brain and nervous system • Huntington’s disease causes damage to nerve cells in the areas of the brain involved in the control of movement, planning and motivation • People with Huntington’s disease are affected by gradual physical, mental and emotional changes. • The early symptoms of Huntington’s • disease include:mild tremor, clumsiness • lack of concentration, problems remembering things, depression • mood changes, sometimes including aggressive behaviour

9. Task 4: inheriting Huntington's Disease • Caused by a Dominant allele – H • A person with Huntingtons has the Genotype – Hh or HH • There are NO Carriers • Normal = hh • What is the chance of 2 heterozygous people having a child with Huntingtons?

10. Task 5: inheriting Huntington's Disease • What is the chance of a normal person and a person with Huntingtons (Hh)?

11. Task 6: Issues with Embryo screening? • Embryos can be screened for the alleles that cause these and other genetic disorders • What do you think?

12. Summary Task: inheritance of diseases • Cystic fibrosis – a disorder of ______ membranes – must be inherited from ______parents. The parents may be _______ of the disorder without actually having the disorder themselves. It is caused by a _________ allele of a gene and can therefore be passed on by parents, neither of whom has the disorder. • Huntington’s disease – a disorder of the _________ system – is caused by a _______ allele of a gene and can therefore be passed on by only _____ parent who has the disorder

13. Extension Task: • Complete exam questions in booklet for inherited diseases

14. Make a note of this info Draw a diagram or picture Discuss Think Investigate Watch Answer question