Chapter 5

Cards (10)

  • Chromosomes - strands of hereditary material
    • Each human nucleus has 23 pairs
    • Egg and sperm cells have 23 unpaired chromosomes
    Genes - sections along each chromosome that controls the chemical reactions that direct development
    • Invisible traits
    • XX - Female
    • XY - Male
    Sex-linked genes are normally found on the X chromosome
    • Sex-linked genes impact males more than females
  • Dominant Trait - expressed in a person even if they only have one copy of that gene
    • Brown Eyes
    • Freckles
    • Dimples
    • Straight Hairline
  • Recessive Trait - requires two copies of the gene to be expressed.
    • Widows Peak
    • Blue Eyes
    • Left-Handedness
  • Color Blindness
    • Genetic (hereditary) condition
    • Pass along the X Chromosome
    • Recessive Trait
    • Red/Green colorblindness affects men more than women
    • Most colorblind women have full colorblindness
  • Monozygotic Twins - one egg is fertilized and splits into two
    • Identical Genes
    • Shared placenta
    • Identical Twins
    Dizygotic Twins - two separate eggs are fertilized at the same time
    • Share half their genes
    • Separate placenta
    • Fraternal Twins
  • Cross-Sectional - compares groups of individuals with different ages at the same time

    Longitudinal - follows a single group of individuals as they develop
  • Sequential Design - compares different people at different ages as they develop

    Combines Cross-Sectional and Longitudinal
    • Zygote - fertilized egg cell
    • Embryo - unborn child until the end of the seventh week following conception, pregnancy is detectable
    • Fetus - eight weeks after conception until birth
  • Infants' Hearing
    • Habituation - decreased response to a repeated stimulus
    • Dishabituation - when a change in a stimulus increases a previously habituated response

    Habituation - initially an infant may be startled with a stimulus, but after time they still hear the stimulus but they have adjusted to it and are no longer startled
    Dishabituation - if the frequency of the sound changes, the infant is once again startled