1. Mendel and His In-Gene-ius Idea…
Big Idea 3: Living systems store, retrieve, transmit, and respond to info essential to life processes.

2. Essential Knowledge
3A3: The chromosomal basis of inheritance provides an understanding of the pattern of passage of genes from parent to offspring.

3. … “particulate” hypothesis is the idea that parents pass on discrete heritable units (genes)…
Gregor Mendel

4. Mendel’s Peas…
Planned experiments using characters (flower color) and traits (purple/white)

5. He Experiments…
Mendel mated 2 contrasting, true-breeding varieties  hybridization
True-breeding parents = P generation
Hybrid offspring of P generation = F1 generation
When F1 individuals self-pollinate = F2 generation is produced

6. Purple = dominant
White = recessive
3:1 Ratio

7. Mendel’s heritable factor = gene Alternate versions =alleles

9. IA Video

10. Law of Segregation and I.A. apply to genes on diff. chromosomes.

11. Genes near each other on same chromosome tend to move as a unit
Probability of segregation is a fxn of the distance b/t them.

12. Dominant vs Recessive
Use Punnett Squares to predict heredity outcomes.
Dominant alleles: Use upper case. Ex: S
Recessive alleles: Use lower case. Ex: s

13. Homozygous: alleles for a trait are same
Homozygous: alleles for a trait are same. Ex: SS or ss or TT (true breeding)
Heterozygous: alleles for a trait are different. Ex: Ss or Tt

14. Ratios Receive 2 types of info: genotype and phenotype.
Genotype: genetic trait that you cannot see (genes)
Phenotype: trait or behavior you can see physically.

15. Genotype
Phenotype
Use probability to analyze passage of single gene traits from parent to offspring

16. Punnett Squares!!

17. One Factor Punnett Square
One trait = monohybrid cross.
Ex: Cross a tall dominant homozygous pea plant (TT) w/ short recessive homozygous pea plant (tt).

18. Monohybrid Cross TT is a parent who is Tall
tt is a parent who is Short
Both are homozygous that make heterozygous offspring.

19. Ratios to Know TT x tt = 100% Dominant, but heterozygous
Tt x Tt = 75% Dominant, 25% Recessive, 3:1

20. Two factor Punnett Square
Cross 2 traits = dihybrid cross.
Example: Cross a dominant green, smooth pea plant (GGSS) with a recessive yellow, wrinkled pea plant (ggss)

21. Ratios to Know SsTt x SsTt = 9:3:3:1 9 dominant in both traits
3 dominant in one trait or the other trait
1 recessive for both traits

22. Human Genetic Disorders
Can be received by inheriting a single gene trait or specific chromosomal change
Ex: Tay-Sachs Disease: Mutation on Chrom causing deterioration of nerve cells.

23. What’s This??

24. Punnett Square Sample Probs