10.1 - Mendel’s Laws of Heredity
Parts of a Flower The Male Parts of a Flower
The Female Parts of a Flower
Fertilization in Plants
Self-Pollination: male & female gametes come from the same plant Cross Pollination: male & female gametes come from different plants
Mendel’s Crosses
Hybrid: offspring of parents that have different forms (alleles) of a trait
The Rule of Dominance
7 Traits studied by Mendel
Phenotype vs. Genotype Genotype: the combination of alleles an
organism has (TT, Tt, tt…) Homozygous: if the 2 alleles for a trait are the
same Homozygous dominant (TT) Homozygous recessive (tt)
Heterozygous: if the 2 alleles for a trait are
different (Tt) Phenotype: the actual characteristic (tall,
short, ….)
Punnett Square: used to determine the expected proportions of possible genotypes of the offspring
Mendel’s Conclusions The Rule of Unit factors: each organism has 2
factors (alleles) that control each of its trait. The Rule of Dominance: The dominant allele expresses itself over the recessive allele. The recessive allele only expresses itself when 2 copies of the allele are present The law of segregation: when gametes are produced, each gamete receives one of the 2 alleles