1. Gregor Mendel: Father of Genetics
• Mendel conducted experiments using garden pea plants
• Cross pollinated flowers and observed traits in offspring
BIO.B Describe & predict observed patterns of inheritance (i.e. dominant, recessive, codominance, incomplete dominance, sex-linked, polygenic and multiple alleles).
Kindlin BIO.B.2.2 Mendelian Genetics PPT 2016

4. Pea Plant Traits

5. Mendel’s Experiment
Mendel developed a true-breeding parent generation, P generation.
True-breeding purple flowered plants always produce purple flowered offspring.
Mendel crossed purple & white flowered plants. The offspring are called the first filial generation, F1 generation. They all had purple flowers.
The offspring of the F1 generation is called the F2 generation.

6. Mendel’s Observations
The observed trait is called dominant.
The dominant trait is represented with uppercase letters.
The hidden trait is called recessive.
The recessive trait is represented with lowercase letters.

8. Genotype Determines Phenotype!
The physical appearance is called phenotype.
For each trait, we have two alleles, or versions of a gene. We get one allele from each parent.
Our set of alleles determines our genotype.
PP = genotype Purple = phenotype
pp = genotype white = phenotype

9. What is a Gene? A gene is the basic unit of heredity.
A gene is a segment of DNA on a chromosome that describes how to make a certain protein.
Each gene is located at a specific locus on the chromosome.
A genome is all of the genetic information for an organism.

10. What will be the genotypes of the offspring? ______ ______

11. Same or Different Alleles?
If both alleles are the same they are called homozygous.
Homozygous Dominant = PP
Homozygous Recessive = pp
If the alleles are different it is called heterozygous.
Heterozygous = Pp

15. TT x Tt Tt x Tt

17. Law of Independent Assortment
Pairs of alleles separate independently during meiosis as long as they are on different chromosomes or far apart on the same chromosome.
Ex. Seed shape and seed color

22. Non-Mendelian Patterns of Inheritance:
Codominance
Incomplete Dominance
Sex-linked
Polygenic
Multiple Alleles

24. Codominance Produces Offspring with Both Phenotypes Expressed

25. Incomplete Dominance Produces a Blending in the Phenotype

27. Colorblindness
is Sex-Linked

29. Pedigree shows the typical inheritance
pattern found in red-green color-blindness

30. Sickle Cell Anemia is Sex-Linked

31. Polygenic Traits Many genes code for a single trait.
You typically see a wide variety of phenotypes as a result.
Examples: Skin color, Hair color, Eye color, Human height

34. Kindlin BIO.B.2.2 Mendelian Genetics PPT 2016