Genetic Disorders

Genetic Disorders:

Sickle cell disease is a genetic disorder caused by faulty alleles. The Sickle cell allele is recessive so only people with two copies of the allele suffer from the disorder.

People with the disease easily become tired and short of breath. Their joints can become very painful because their red blood cells stick together and block blood vessels. This can sometimes be fatal.

Another genetic disorder also caused by a recessive allele is cystic fibrosis. People with the disorder have their lungs clogged with thick mucus making breathing difficult which leads to infections. It also blocks tubes that carry enzymes to the small intestine. This can result in weight loss.

A family pedigree chart shows which members of a family suffer from a disorder. It allows you to see how a genetic disorder is passed on in a family.

Doctors use pedigree charts to work out the probability that a person may have inherited the disorder from their parents. This is called Pedigree analysis.


Key Words:

Sickle cell disease
Genetic disorder
Cystic Fibrosis
Family pedigree chart
Pedigree analysis


Questions:

1. State two symptoms of Sickle cell disease?
2. State two symptoms of Cystic fibrosis?
3. Why can't people catch sickle cell disease like catching a cold?
4. Why might Cystic Fibrosis sufferers lose weight?
5. Cystic fibrosis is a recessive genetic disorder. Explain what this means.


What you should've learnt:

How to analyse and interpret patterns of monohybrid inheritance using a genetic diagram and family pedigrees.

The symptoms of the genetic disorders: a. Sickle Cell Disease   b. Cystic Fibrosis

The outcomes of pedigree analysis when screening for genetic disorders a. Sickle Cell Disease  B. Cystic Fibrosis.