BIOLOGY 151 Lecture Notes - Lecture 37: Punnett Square, Stamen, Preformationism
Document Summary
Theory of epigenesis- organism derived from substances present in the egg and assembled during embryonic development. Theory of preformationism -sex cells contain complete miniature person. Blending inheritance-black rabbit + white rabbit = gray rabbit. Spontaneous generation- living things are created from nonliving things- maggots. Everything he did was before they knew dna was genetic material. True-breeding- round seed + round seed always results in a smooth pod. Controlled pea plants by removing stamen and manually transferring pollen to other flower. P generation: tall x dwarf true-breeding: tt x tt. F1 generation: all tall offspring - hybrids- tt tt tt tt. F2 generation: 75% tall 25% dwarf- tt tt tt tt. All offspring in f1 generation are tt because one trait is donated by each parent. Genotype: genetic composition of individual- particular combination of alleles. Phenotype: characteristics that you see- the expression of a trait. 3 important ideas: dominant and recessive traits. Recessive is masked by dominant: genes and alleles.
