Intro to Genetics

Genetics

The study of heredity

Heredity

The transmission of traits from parent to offspring

Law of Dominance

Dominant trait is a version of trait that expresses itself over another

Alleles

Alternative forms of a gene (trait) inherited in pairs = one from each parent

Dominant traits

Traits that express themselves over recessive traits

Recessive trait

Trait that can be 'hidden' by dominant traits

Genotype

Organism's genetic makeup (the genes, aka LETTERS)

Phenotype

What the organism looks like (appearance)

Homozygous

Having identical alleles for a trait (purebred)

Heterozygous

Having different alleles for a trait (hybrid)

Punnett Squares

A method to predict the genotype of offspring by writing one parent genotype across the top and one on the left

Dominant trait

Round = letter is R

Recessive trait for seed shape

Wrinkled = letter is r

Dominant trait for seed color

Yellow = letter is Y

Recessive trait for seed color

Green = letter is y

Example of genotype for Tall plants

TT or Tt

Example of genotype for Short plants

tt

allele

alternative forms of a gene inherited by each parent

incomplete dominance

one allele does not completely dominate another, resulting in a blended phenotype.

codominance