Higher Human biology

• Monitoring the health of the mother, developing baby, and fetus


  A variety of techniques can be used
• Antenatal screening


  Identifies the risk of a disorder so that further tests and a prenatal diagnosis can be offered
• Antenatal screening tests


  • Ultrasound
  • Blood and Urine Tests
  • Diagnostic Testing
• Antenatal screening tests


  1. Routine blood and urine tests

  2. Dating scan (8-14 weeks)

  3. Amniocentesis

  4. Anomaly scan (18-20 weeks)

  5. Chorionic villus sampling (CVS)
• Dating scans


  Determine stage and due date
• Chorionic villus sampling (CVS)


  Can be carried out earlier in pregnancy than amniocentesis, although it has a higher risk of misscarriage
• Anomaly scans

  May detect serious physical abnormalities in the fetus
• Postnatal screening


  Routine testing for metabolic disorders after birth
• In the UK, all newborn babies are routinely screened for Phenylketonuria (PKU)
• Phenylketonuria (PKU)


  A substitution mutation means that the enzyme which converts phenylalanine to tyrosine is non-functional. Individuals with high levels of phenylalanine are placed on a restricted diet
• Autosomes


  Any chromosome that isn't a sex chromosome
• Sex chromosome


  X and Y chromosome
• Autosomal recessive inheritance


  • For a recessive trait to appear, both parents must be carriers
• Incomplete dominance inheritance


  • Affected individuals must have two carrier parents
• Autosomal dominant inheritance


  • Dominant traits appear in every generation
• Sex-linked recessive inheritance


  • For females to be affected by sex-linked disorders, the father has to be affected and the mother a carrier