Science 2024 semester 1

• There are 46 chromosomes in a human nucleus:

  23 from mother, 23 from father
• Heterozygous: 2 different alleles, e.g Bb
• carrier: allele for recessive trait that does not show on phenotype
• recessive trait: characteristic that is only expressed in phenotype if both alleles are recessive
• dominant trait: trait that only needs one copy of the allele to be expressed