Fundamentals of Genetics

Gregor Mendel Mendel was an Austrian monk who studied genetics by using pea plants. Mid 1800’s

Gregor Mendel Mendel observed different characteristics of the plants (called traits).

Gregor Mendel When he planted the offspring seeds of purple flowered plants, he noticed that the flowers were purple and white. This lead to the question of “WHY?”.

Gregor Mendel A pure trait is one that always produces offspring with that trait.

Generations Parental Generation = P1 Cross pollination of the P1 generation results in the F1 generation. F = Filial Cross pollination of the F1 generation results in the F2 generation.

Recessive vs. Dominant Traits Dominant = a trait that hides the presence of another trait for the same characteristic. Recessive = a trait that is hidden by the presence of another trait. Free = Dominant Attached = Recessive

The Law of Segregation A pair of factors is separated during the formation of gametes.

The Law of Independent Assortment The factors for different characteristics are distributed to gametes independently.

It’s in your Genes A gene is a segment of DNA on a chromosome that controls a particular hereditary trait.

It’s in your Genes Alleles are the alternative forms of a gene.

Geno. Vs. Pheno. Genotype is the genetic makeup of an organism. It is often written with letters such as TT, Tt, or tt.

Geno. Vs. Pheno. Phenotype is the external appearance of an organism. Such as Tall, Short, Green, Yellow

Hetero. Vs. Homo. “Homo” means the same “Hetero” means different Homozygous dominant : TT Heterozygous: Tt Homozygous recessive: tt

Probability The likelihood that a specific event will occur. It is expressed as a decimal, percent or fraction.

Probability Formula # of times an event is expected to happen # of opportunities for an event to happen

Punnett Squares Used to predict probability in various crosses.

Monohybrid Cross Involves only one pair of contrasting traits.

Dihybrid Cross Involves two pairs of contrasting traits.