father of genetics

McKinney ISD Austria Italy Johann Mendel Germany Poland Austria Czech Republic was born in 1822 in Heinzendorf, Austria, to a peasant farming family. He was an Austrian Monk with a love of science.

McKinney ISD During his early years at the monastery, Mendel began studying and breeding mice. The bishop was not pleased.

McKinney ISD Brother Gregor settled on bees...

McKinney ISD and peas.

McKinney ISD Mendel narrowed his focus to one particular garden pea, Pisum sativm. Mendel continued to conduct numerous experiments on plants. For 8 years, Mendel experimented with over 28,000 peas in the large gardens attached to the monastery.

McKinney ISD Rather than study every characteristic of the garden pea, Mendel narrowed his observations to 7 traits.

McKinney ISD Garden Pea Traits Observed

McKinney ISD smooth wrinkled yellow green inflated constricted green yellow purple white axial terminal tall short Seed shape Seed color Pod shape Flower color Flower location Plant size Pod color

McKinney ISD In 1866 when Mendel was 44, his experimental results were published... and ignored long after he died.

McKinney ISD Alleles: the different forms of a trait a gene may have You get ONE allele from each parent

McKinney ISD Examples in pea plants : -short or tall plants -red or white flowers -green or yellow peas

McKinney ISD Alleles : can be 1.Dominant-meaning they cover up the other alleles or they can be 2.Recessive –meaning they can be covered up or can seem to disappear

McKinney ISD DOMINANT alleles : written in CAPITAL LETTERS recessive alleles : written in lower case letters

McKinney ISD If the alleles are the same they are called homozygous (also known as purebred). Example: TT or tt (both parents gave the same allele) If the alleles are different they are called heterozygous (also known as hybrid). Example: Tt (parents gave different alleles)

McKinney ISD Genotype vs. Phenotype The genotype of an organism is its genetic makeup Example: TT=homozygous dominant Tt=homozygous recessive Tt=heterozygous The phenotype of an organism is the way the organism looks and/or behaves (what you see) Example: short, blue eyes, brown hair, etc…

McKinney ISD For the recessive allele or form of a trait to be seen, the genotype must be homozygous recessive tt phenotype=short The dominant form will show either homozygous dominant OR heterozygous TT and Tt phenotype=tall

McKinney ISD Punnett square A punnett square is: a simple chart for predicting the results of a cross. It shows the _________: the genetic makeup of an organism and the ________: the way an organism looks or behaves genotype phenotype