1. Mendel…….. The Father of Genetics

2. Mendel (1866) Austrian Monk Gardener & Mathematician / Statistician
Bred pea plants for different traits
Pea plants self-pollinate so all the pea plants in a patch would all have the same genes = true breeding

3. Mendel cross-pollinated peas
Anthers make pollen =
male gametes
Cross pollination
= gametes from different flower fertilize the eggs

4. Mendel discovers each parent has 2 copies of gene
Different versions of gene
Mendel discovers dominant & recessive
Law of segregation
Law of independent Assortment
Sources of variation

5. Gene = DNA code for one protein
Protein causes trait
Trait = characteristic = phenotype

6. Alleles = versions of a gene
For example if the gene is height the alleles are
tall and short
If the gene is seed color the alleles are
green and yellow
If alleles are blue and brown the gene could be
eye color

7. Dominant vs. Recessive Alleles
Dominant alleles overshaddow recessive alleles if an individual gets one of each
Dominant alleles … use a Capital letter
Recessive alleles …use a lower case letter
For height Tall is dominant & short is recessive
Tall = H short = h the gene is height
Same gene must use the same letter of the alphabet

8. Genotype vs. Phenotype
Genotype = what type of alleles you have ex. HH, Hh, or hh
Homozygous dominant = HH
Homozygous recessive = hh
Heterozygous = Hh
Phenotype = what type of physical appearance you have
short (recessive) or tall(dominant)

9. Determining phenotype
All individuals with even one dominant allele
look like the dominant trait
The only way to look recessive is to have
two copies of the recessive allele
hh = looks short
Hh = looks tall HH = looks tall

10. Determining Genotype Any individual that looks recessive has….
2 recessive alleles (hh)
Any individual that looks like dominant trait has:
………at least one dominant allele (H ?)
The second allele can only be determined if…
...the individual’s parent or child looks recessive
if a parent or child look recessive the individual
……… is heterozygous (Hh)

11. Generations in genetics experiments
P generation = parents
(first 2 individuals crossed)
F1 generation = offspring of the original parents
F2 generation = offspring resulting from a cross of two F1 individuals

12. Punnett Squares – used to predict the phenotypes / genotypes of offspring

14. Pedigree = a diagram of a families' genetic history
Black circles /squares show individuals with the phenotype being studied
If a circle or square is half shaded in … the individual is heterozygous for the trait being studied