80 likes | 207 Views
Genetics- the study of heredity. Heredity- passing of traits from parent to offspring. Gregor Mendel- The Father of Genetics. Austrian monk lived in a monastery in charge of the garden. Noticed that some plants were tall, some were short, etc. Wanted to find out how 2 tall
E N D
Genetics- the study of heredity Heredity- passing of traits from parent to offspring
Gregor Mendel- The Father of Genetics • Austrian monk lived in a monastery in charge of the garden. • Noticed that some plants were tall, some were short, etc. Wanted to find out how 2 tall plants could produce a short plant and vice versa. • Begin experimenting with pea plants.
The Work of Gregor Mendel • Mendel used pea plants b/c: • Had a lot of traits to study and produced offspring fast.
The original pair of plants that were crossed were called the P (parental) generation. One tall and one short. • The offspring of this cross were called the F1 (first filial) generation. Resulted in 2 tall plants. • Offspring from the F1 generation produced the F2 generation. Resulted in 3 tall and one short. • Where did the short plant come from????
Results from Mendel’s Experiment • Principle of Dominance: some alleles are dominant and some are recessive. • If dominant is present, it will mask the recessive allele.
Genes and Alleles • Genes: chemical factors that determine a trait (characteristic). • Allele: different forms or ways of expressing a gene. • Ex: AA, Aa, aa • Dominant Allele: the trait that always shows physically and is represented by a CAPITAL letter. • Ex: AA or Aa • Recessive Allele: only shows if the dominant allele is not present. • Ex: aa
Homozygous (same) vs. Heterozygous (different) • Homozygous or Purebreed: 2 identical alleles. • Ex: AA= homozygous dominant aa= homozygous recessive • Heterozygous or Hybrid: 2 different alleles. • Ex: Aa= heterozygous (always dominant)
Phenotype vs. Genotype • Phenotype: physical characteristics of the organism (what it actually looks like). • Ex: tall plant or short plant • Genotype: genetic make up of the organism (what the alleles are). • Ex: AA, Aa or aa