CHAPTER 11: Complex Inheritance and Human Heredity

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CHAPTER 11 Complex Inheritance and Human Heredity

• BIOLOGY

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11.1 Basic Patterns of Human Inheritance

• RECESSIVE GENETIC DISORDERS a recessive trait
  is expressed when the individual is HOMOZYGOUS
  RECESSIVE for that trait bb
• Carrier is an individual who is HETEROZYGOUS
  recessive (Bb) for a recessive disorder.
• CYSTIC FIBROSIS, ALBINISM, TAY-SACHS DISEASE, AND
  GALACTOSEMIA
• COPY CHART ON PG 297 IN NOTESCOPY DISORDER,
  CAUSE, EFFECT, AND TREATMENT do it now please

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Dominant Genetic Disorders

• Huntingtons Disease affects nervous system,
  symptoms first appear between ages of 30-50 yrs
  old., gradual loss of brain function,
  uncontrollable movements, and emotional
  disturbances, NO PREVENTATIVE TREATMENT OR CURE
  EXISTS

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• Achodroplasia person has small body with
  similarly short limbs, most common form of
  dwarfism, avg height of 4 ft, normal life
  expectancy, 75 born to normal sized parents due
  to new mutation or genetic change.

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Pedigrees

• A pedigree is a diagram that traces the
  inheritance of a particular trait through several
  generations.

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11.2 Complex Patterns of Inheritance

• Incomplete dominance heterozygous phenotype is
  an intermediate phenotype between the two
  homozygous phenotypes
• Codominance both alleles are expressed in the
  heterozygous condition
• Sickle-cell disease genetic changes in the
  proteins in hemoglobin cause cells to change to
  sickle shapedo not transport oxygen well
• Sickle-cell and Malaria people who are
  heterozygous for sickle-cell disease are more
  resistant to Malaria

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Multiple Alleles

• Blood groups in Humans ABO groups have 3
  alleles IA type A, IB type B, i type O (no
  AB markers)..i is recessive to IA and IB, IA and
  IB are codominant
• Blood Types A, A-, AB, B, B-, O, O-

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• Epistasis varying coat colors. Yellow black
  in labsthese traits have two alleles for each
  trait 1 for pigment/not, the other for how
  dark/light the pigment is
• Sex Chromosomes determine an individuals
  gender. XX female.. XY male
• Autosomes non-sex chromosomes.the other 22
  chromosome sets that determine skin tone, eye
  color, hair type, etc.

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Dosage Compensation

• Chromosome inactivation parts of the X
  chromosome dont activate correctly causing
  blotches.calico cats
• Barr Bodies only females of any species have
  these

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Sex-Linked Traits

• Sex-Linked Traits traits controlled by genes on
  the X and Y chromosomes
• Males have only 1 X so they are more likely to
  show X-linked recessive traits (male pattern
  baldness)
• Red-green Colorblindness recessive X-linked
  trait8 of males in the US have this
• Hemophilia delayed clotting of bloodeasy
  bleedersmore men than women.men die at early age

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Polygenic Traits

• Polygenic traits arise from the interaction of
  many alleles for the same traitskin color,
  height, eye color
• Environmental Influences certain traits can be
  inherited (heart disease) but your environment
  can also have a large affect (diet)