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Biology LibreTexts

3.S: Genetic Analysis of Single Genes (Summary)

  • Page ID
    4022
  • [ "article:topic", "OOG", "OGG", "authorname:tnickle" ]

    • A diploid can have up to two different alleles at a single locus. The alleles segregate equally between gametes during meiosis.
    • Phenotype depends on the alleles that are present, their dominance relationships, and sometimes also interactions with the environment and other factors.
    • Classical geneticists make use of true breeding lines, monohybrid crosses, Punnett squares, test crosses, reciprocal crosses, and the chi-square test.
    • Sex-linked genes are an exception to standard Mendelian inheritance. Their phenotypes are influenced by the type of sex chromosome system and the type of dosage compensation system found in the species.
    • The male/female phenotype (sex) can be determined by chromosomes, genes, or the environment.

    Key Terms

    allele

    Mendel’s First Law

    Law of Equal Segregation

    homozygous

    heterozygous

    hemizygous

    wild-type

    variant

    locus

    genotype

    phenotype

    dominant

    recessive

    complete dominance

    incomplete (semi) dominance

     

     

    co-dominance

    ABO blood group

    haplosufficiency

    haploinsufficiency

    classical genetics

    molecular genetics

    true breeding lines

    monohybrid cross

    Punnett Square

    test cross

    tester

    sex-linked

    dosage compensation

    X-linked genes

    autosomal genes

    reciprocal cross

    Z-linked genes

    hermaphrodites

    parthenogenesis

    hormonal

    cell-autonomous

    sexual gynandro-morphs

    sexually dimorphic

    gynandromorphy

    mosaic

    chimera

    G + E = P

    penetrance

    expressivity

    sampling effects

    chi-square χ2 test

     

     

     

    Contributors