Wake-up 1.A woman carrying hemophilia marries a man who is a hemophiliac. What percentage of their children will have hemophilia? 1.Cross a man heterozygous B with a woman who is a purebred for A. What blood types will their children have?
Human Genetic Disorders and Pedigrees Christopherson
Human Genetics: Karyotypes 46 TOTAL 23 homologous pairs 46 TOTAL 23 homologous pairs
Sex Chromosomes 2 sex chromosomes Typical Female = XX Typical Male = XY
Autosomes Autosomes: Any chromosome that’s not a sex chromosome 44 Autosomes 22 pairs of Autosomes
Recessive Disorder Caused by 2 recessive alleles
Albinism Defect of melanin production that results in little or no color in the skin, hair, and eyes
Albinism
How does it happen? Affected Genotype: aa
Cystic Fibrosis Disease that causes the body to produce unusually thick, sticky mucus that: Clogs the lungs and leads to lung infections Obstructs the pancreas Stops natural enzymes from helping the body break down and absorb food
How does it happen? Affected Genotype: cc
Sickle Cell Anemia Caused by an abnormal hemoglobin shape which causes the red blood cells to have a crescent shape. Red blood cells carry oxygen.
How does it happen? Affected Genotype: ss
Dominant Disorder Caused by a dominant allele Affected individuals are homozygous dominant or heterozygous
Huntington’s Disease Causes the break down of brain cells, (neurons) in certain areas of the brain. Causes uncontrolled movements, loss of intellectual faculties, and emotional disturbance.
How does it happen? Affected Genotype: HH or Hh
Sex-Linked Disorder Linked to sex chromosomes Recessive Disorders – caused by recessive alleles
Color Blindness Inability to see colors in the normal way
How does it happen? Affected Genotypes: X b X b X b Y
Hemophilia Inability of the blood to clot properly
How does it happen? Affected Genotypes: X h X h X h Y
Wake-up 1.What are the genotypes for individuals affected with the following disorders: a.Cystic Fibrosis b.Colorblindness c.Huntington’s disease 2.A parent has a genotype Bb. What alleles can this parent give their children?
What is a Pedigree??? Diagram showing a family tree and patterns of inheritance.
Types of Pedigrees: Recessive Affected Genotypes: bb Unaffected Genotypes: BB or Bb HINT: Recessive Disorders skip generations
Is the Pedigree below showing Recessive Inheritance?
Recessive Inheritance?
Types of Pedigrees: Sex-linked Affected Genotypes: X b X b or X b Y Unaffected Genotypes: X B X B or X B X b and X B Y HINT: Mainly males are affected
Is the Pedigree below showing Sex-Linked Inheritance?
Sex-linked Inheritance?
Types of Pedigrees: Dominant Affected Genotypes: BB or Bb Unaffected Genotypes: bb
Is the Pedigree below showing Dominant Inheritance?
Dominant Inheritance?
How many generations? What is genotype of Individual I- 1? What type of Inheritance?
How many generations? What is genotype of Individual I- 1? What type of Inheritance?