FERTILIZATION & Intro to Mendelian Genetics

FERTILIZATION

In vitro Fertilization

EMBRYO DEVELOPMENT

TWINS

Mendel and His Peas

Results Tall x Tall F1 offspring #3 X F1 offspring # 3 Tall Tall Conclusion? Short x Short Tall x Short Conclusion?

Conclusions Every characteristic or trait (e.g. height) is determined by two factors (alleles). There are variations in alleles (e.g. height= tall (T) or short (t)) Genotype: What combination of alleles an individual has (TT, Tt, tt) Homozygous: individual has two of the same alleles (TT, tt) Heterozygous: individuals have two different alleles (Tt)

Phenotype: What the individual physically looks like (determined by genotype) Dominant allele: The allele that shows up physically in the heterozygous form Recessive allele: The allele that is not displayed physically in the heterozygous form

Is Dominant the most common allele in the population?

GenotypePhenotype Homozygous TallTTTall Heterozygous TallTtTall Homozygous Short ttShort

Mendel’s Law of Segregation Each allele separates into different gametes during meiosis therefore only one allele is passed down to the offspring T t T tT T tt T t meiosis DNA replication

Explaining Mendel’s Observations