1. Genetics
A Monk and his Methods

2. Gregor Mendel In 1865 he published his observations of pea plants.
His work went unnoticed for several decades, before the realization of his genius set in.

3. What did he do? He worked with Pea plants.
He noted several variations in the characteristics of his plants
Variations such as
Flower color (Purple or White)
Seed Texture (Round or Wrinkled)

6. Careful Observations
Mendel did several experiments where he cross-bred (mated) plants of various characteristics.
He took careful notes and recorded all of his observations
Mendel made some astounding conclusions

9. The Conclusions
Mendel noted that some traits seemed to prevail over others…..
An example:
Mendel cross bred a pea plant with white flowers and a pea plant with purple flowers. The majority of plants produced had purple flowers, few had white flowers.

10. Why is this important?
These observations lead to the conclusion that certain traits are DOMINANT over other traits.
The traits that are not DOMINANT are called RECESSIVE.

11. Patterns of Inheritance
Mendel noted these patterns of inheritance among pea plants.
Today we can apply these ideas to human inheritance.

12. Let’s Take a Closer Look
What is actually happening when traits are inherited????
Remember traits (genes) are carried on CHROMOSOMES.
You have TWO copies of EACH chromosome.
This means you have TWO copies of EACH gene.

14. Your Genes
You received one half of your genes from your mother and the other half from your father.
These genes complement each other and express themselves as a PHENOTYPE.
PHENOTYPE- physical characteristic of an organism (What you see)

15. Phenotype Vs. Genotype
Your phenotype (what you see) may be different than your GENOTYPE
GENOTYPE- the combination of ALLELES that an organism has for a trait
ALLELE- a variation of a trait

16. Let’s Check it Out

18. Dominant Vs Recessive
Some alleles are Dominant and some are Recessive

20. Homozygous and Heterozygous
Genotypes can be Heterozygous or Homozygous.
A Heterozygous genotype has one of each allele. (Aa)
A Homozygous genotype only has one type of allele (aa or AA)

21. Recessive
Only those individuals who have the homozygous recessive genotype will have the recessive phenotype.