Genetics: Mendel’s Work Omit Blue Text

Gregor Mendel Lived from 1822-1884 Priest – lived on a monastery High-school teacher, gardener Grew hundreds of pea plants Over 10 years he studied the plants and formed the foundation of genetics

Vocabulary Trait = physical characteristic Heredity = passing of traits from parents to offspring Genetics = scientific study of heredity Purebred = produces offspring with the same form of a trait as the parent

Mendel’s Experiments x Purebred Tall Purebred Short He called this the parental generation or “P generation”

Mendel’s Experiments Result? The short trait had disappeared! F1 Generation – “F” stand for filial or “son” in latin

Mendel’s Experiments + So he crossed two of the plants from the F1 generation… +

Mendel’s Experiments The missing trait had reappeared! F2 Generation What % are tall plants? What % are short plants?

More Vocabulary Traits are controlled in pairs Gene = factor that controls a trait Allele = ½ of a gene – one from mom and one from dad

Chromosome Alleles (letters)

Some alleles are dominant while others are recessive.

Dominant vs Recessive Dominant alleles are traits that are always shown Recessive alleles can be covered up or hidden when the dominant allele is present. A trait expressed by a recessive allele will only show up if there is no dominant allele present.

In Mendel’s Experiments… Tall Allele Short Allele is dominant over

Chromosome 1 Chromosome 2 1 Gene 2 Alleles Chromosome Pair

Bb = Eye Gene B = Brown b = blue

Vocabulary Example: “Bb” Hybrid - have two different alleles for a trait Example: “Bb” Recessive Dominant

Questions?