1. Genetics and Heredity Genetics is the study of heredity
Heredity is how different genes are passed down from parents to children

2. Genes Your GENES, not your JEANS.
A gene is a segment of DNA that codes for a certain trait

3. Genetics Terminology: Genome, Chromosomes & Genes
________ -Complete complement of an organism’s DNA.
Cellular DNA is organized in ___________.
______ have specific places on chromosomes.
Genome
Chromosomes
Genes
From the Virtual Cell Biology Classroom on ScienceProfOnline.com

4. Gregor Mendel (lived in 1800s)
Austrian monk who taught natural science
Interested in how traits are passed on
Crossbred snow pea plants to figure it out
Is known as “The father of Genetics”
Genetics- the study of heredity

5. The work of Gregor Mendel
Earlier Notions of Inheritance
Blending
Spermists
Ovists
Mendel was first to show both parents contribute equally

6. “Father of Genetics”
Mendel performed breeding experiments with garden peas
Found mathematical patterns of inheritance
His work was not appreciated until 1900, 16 years after his death

7. Mendel’s work Why breed peas?
They were available in many varieties, inexpensive, short life cycle, simple procedures, easy to grow.
The use of plants also allowed strict control over the mating.
He chose to study only characters that varied in an ‘either-or’ rather than a ‘more-or-less’ manner.

8. Why peas?
-not too many traits to keep track of
-Pea traits-pea color, pea shape, plant height, pod shape, pod color, flower color, flower position

9. Mendel crossed purple flowers with white flowers. (Purebreds)
- all of the resulting flowers were purple
Then he let the F1s self-fertilize.
Result in F2 generation:
-  75% of the flowers purple
25% of the flowers white Explain! F1

10. Interpreting Mendel’s Data
Parent Cross
F1 generation
F2 generation
Actual Ratio
Probability Ratio
Round x wrinkled
100% round
5,474 round 1,850 wrink.
2.96:1
3:1
Yellow x green pea
100% yellow
6,022 yell
2,001 green
3.01:1
Long x short stem
100% long stem
787 long
277 short
2.84:1

11. Mendel’s Observations
“dominant” vs “recessive”
Before “genes” and “meiosis” were known, Mendel theorized “inheritance factors”…
are in the pollen and ova of peas as alternate forms for different traits.
occur in pairs, (equal contribution from both parents)
separate during gamete formation and pair up again at fertilization

12. Mendel's Laws 1. Law of Dominance 2. Law of Segregation
3. Law of Independent Assortment
Image: Gregor Mendel, Mendel's Principles of Heredity: A Defense by Bateson, William.
From the Virtual Cell Biology Classroom on ScienceProfOnline.com

13. 1. Mendel’s Law of _________
• In a cross of parents that are pure for contrasting traits, only one form of the trait will appear in the next generation. 
• Offspring that are hybrid for a trait will have only the dominant trait in the phenotype.
Dominance

14. Mendel’s Law of Segregation
Each hereditary characteristic is controlled by two factors (alleles) that separate and pass into reproductive cells (gametes).

15. 2. Mendel’s Law of ________
Alternative versions of genes (alleles) result in variations in inherited characteristics.
For each character, an organism inherits 2 alleles (one from each parent).
The alleles for each character segregate (separate) during gamete production (_______).
Alleles for a trait are recombined at fertilization, becoming genotype for the traits of the offspring.
Table showing how the genes exchange according to segregation or independent assortment during meiosis and how this translates into Mendel's laws.
Segregation
meiosis

16. Mendel’s Law of Independent Assortment
Pairs of inheritance factors (alleles) segregate independently of each other when sex cells (gametes) are formed.

17. 3. Mendel’s Law of _____ ______
Diagram of how the genes exchange according to segregation or independent assortment during meiosis and how this translates into Mendel's laws.
Alleles for different traits are distributed to sex cells (& offspring) independently of one another.
Show me a video!
Remember…Mendel came up with this stuff BEFORE we know about the existence of DNA, genes, chromosomes!
Independent Assortment
Image: Independent assortment and segregation diagram, Mariana Ruiz.
From the Virtual Cell Biology Classroom on ScienceProfOnline.com

18. Mendel’s Laws: 2. Law of Segregations:
1. Law of Dominance:
- In a cross of parents that are pure for
contrasting traits, only one form of the
trait will appear in the next generation.
- Offspring that are hybrid for a trait will
have only the dominant trait in the phenotype.
2. Law of Segregations:
- During the formation of gametes (eggs or sperm), the two alleles (hereditary units) responsible for a trait separate from each other. 
- Alleles for a trait are then "recombined" at fertilization, producing the genotype for the traits of the offspring.
3. Law of Independent Assortment:
- Alleles for different traits are distributed to sex cells (& offspring) independently of one another.
Image: Gregor Mendel, Mendel's Principles of Heredity: A Defense by Bateson, William
From the Virtual Cell Biology Classroom on ScienceProfOnline.com

19. Mendelian Inheritance in Humans dominant recessive
Tongue Roller (T)
Free Earlobes (F)
Dimples (D)
Widow’s Peak (P)
Can’t roll tongue (t)
Attached lobes (f)
No dimples (d)
Straight hairline (w)

20. Genetics and Probability
Discuss…
Coin flipping
Card picking
Punnett Square probability vs actuality

21. Some Vital Vocab. Genetics Gene vs Chromosome Alleles
Dominant vs Recessive

22. Some Vital Vocab. Genotype vs Phenotype Homozygous vs Heterozygous
Diploid vs Haploid
Mitosis vs Meiosis
Zygote

23. Problem Solving from Mendelian Genetics
Consider inheritance patterns for
Cystic Fibrosis
Sickle Cell Anemia
Huntington’s disease
Hemophelia
Colorblindness pedigree

24. Exceptions to Complete Dominance
Polygenic Traits
Intermediate Expression (aka incomplete dominance)
Multiple Alleles
Several described at this link!