5.2 Human Genetic Disorders Human Heredity 5.2 Human Genetic Disorders

POINT > Define a gene in simple terms POINT > Define and describe genetic mutations POINT > Distinguish between gene and chromosomal mutations POINT > Describe examples of genetic diseases caused by single gene mutations POINT > Identify human diseases caused by chromosomal mutations POINT > Explain Pedigree analysis

POINT > Define a gene in simple terms One gene is a sequence of DNA that codes for one protein There are 1000’s of different proteins in a cell Each protein has an important function in the cell The DNA sequence in a gene determines the amino acid sequence in a protein The amino acid sequence of the protein has to be correct! If not...

Werewolf

POINT > Define and describe genetic mutations A mutation is a change to the DNA sequence of an organism A gene mutation affects only one gene/one protein A chromosomal mutation affects the number of chromosomes in the cell. This affects many genes

POINT > Define and describe genetic mutations If the DNA is altered, the mutation is passed to daughter cells through mitosis If the mutation occurs in an egg cell or sperm cell, the changes are passed to offspring

CHECK: What is a mutation? What is a gene mutation? What is a chromosomal mutation?

The Mummy

POINT > Describe human diseases caused by single gene mutations Cystic fibrosis: a recessive allele carries a mutation that causes mucus to fill the lungs Difficulty breathing and death are the results of this disease

POINT > Describe human diseases caused by single gene mutations 2. Sickle cell anemia: A codominant allele causes some red blood cells to be misshaped Blood doesn’t carry oxygen as well

POINT > Describe human diseases caused by single gene mutations Hemophilia: A sex-linked (X chromosome) recessive allele causes blood to not clot Patients have excessive bleeding

CHECK: What kind of allele causes cystic fibrosis? What kind of allele causes sickle cell anemia? What kind of allele causes hemophilia ?

Frankenstein monster

Varying degrees of mental retardation POINT > Identify human diseases caused by chromosomal mutations Down’s syndrome: 1 extra chromosome (#21) Varying degrees of mental retardation Many distinct physical characteristics

POINT > Identify human diseases caused by chromosomal mutations Edward’s syndrome 1 extra chromosome (#18) Major physical abnormalities & mental retardation ~3% of cases result in live birth, median lifespan is 5-15 days

CHECK: What causes Down’s syndrome? What causes Edwards syndrome?

Dracula

POINT > Explain pedigree analysis

POINT > Explain pedigree analysis Pedigree analysis is used to trace a disease or trait in a family history

POINT > Explain pedigree analysis Examples of symbols: Female: Male: You must learn the symbols of the pedigree charts before you can start to learn how to interpret it. These are the symbols that represent a male and a female.

POINT > Explain pedigree analysis Examples of symbols: Married Couple: Offspring: These symbols also represent relationships between people. some may have to each other.

POINT > Explain pedigree analysis Empty shape = unaffected  Carrier. Has allele, but not the disease/trait  Has the disease/trait

Color Blindness About 1 in 10 men have some form of color blindness. Sex-linked recessive disorder Can get color blind from nerve damage, or drugs (one drug used to treat arthritis causes color blindness), but most of the time is a genetic disorder. Color blindness is a life long condition, doesn’t impact day to day life that much. Color blind people may not be able to do certain jobs that require seeing color, like a fashion designer or a cook who needs to be able to tell when the meat is done, or an electrician who can’t tell the difference between wire colors that she or he needs to cut

Homework: Read pages 151-155 S.A. #1-3 page 155 GRAS pages 72-73 Pedigree analysis Worksheet