Year 10 – Genetics and Biotechnology (Biology)

Genetic disorders

Year 10 – Genetics and Biotechnology (Biology)

• 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

Year 10 – Genetics and Biotechnology (Biology)

Starter:

Disease of nervous system = Dominant

Disease of cell membranes /lungs = recessive

Cystic fibrosis Huntington's

Year 10 – Genetics and Biotechnology (Biology)

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

Year 10 – Genetics and Biotechnology (Biology)

Task 1: Cystic fibrosis

1. What is Cystic fibrosis and what organs does it mainly affect?

2. What treatment is required?

Year 10 – Genetics and Biotechnology (Biology)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?

C c

C

c

Year 10 – Genetics and Biotechnology (Biology)Task 3: inheriting Cystic

Fibrosis

• What is the chance of a homozygous recessive person and a normal person having a child with CF?

Year 10 – Genetics and Biotechnology (Biology)

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

Year 10 – Genetics and Biotechnology (Biology)

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?

Year 10 – Genetics and Biotechnology (Biology)

Task 5: inheriting Huntington's Disease

• What is the chance of a normal person and a person with Huntingtons (Hh)?

Year 10 – Genetics and Biotechnology (Biology)

Task 6: Issues with Embryo screening?

• Embryos can be screened for the alleles that cause these and other genetic disorders

• What do you think?

Year 10 – Genetics and Biotechnology (Biology)

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

Year 10 – Genetics and Biotechnology (Biology)

Extension Task:

Complete exam questions in booklet for inherited diseases

Year 10 – Genetics and Biotechnology (Biology)

• Make a note of this info

• Draw a diagram or picture

• Discuss

• Think

• Investigate

Watch

Answer question