1. Genetics Mr. Skirbst Life Science Topic 08

2. Genetics

3. the study of heredity

4. Genetics the study of heredity Heredity is the passing of traits to offspring

5. Genetics the study of heredity Heredity is the passing of traits to offspring Traits are characteristics of an organism (ex. Hair color, eye color, skin color, etc.)

6. GENES - units of heredity

7. GENES - units of heredity Dominant – stronger trait “T”

8. GENES - units of heredity Dominant – stronger trait “T” Recessive – weaker trait “t”

9. Genetics Zygote – fertilized egg

10. Genetics Zygote – fertilized egg Homozygous (purebred) – Contains all one trait (ex. TT or tt)

11. Genetics Zygote – fertilized egg Heterozygous (hybrid) – Contains mixed traits (ex. Tt)

12. Genetics Phenotype – physical appearance (ex. Hair color)

13. Genetics Phenotype – physical appearance (ex. Hair color) Genotype – Genetic makeup (ex. Tt or TT)

14. Probability

15. - the possibility (or likelihood) that an event will happen (ex. flipping a coin, lottery, rain, characteristics of offspring)

16. Probability Punnett Square:

17. Probability Punnett Square: - used to show possible gene combinations in a cross between two organisms (shows genetic probability)

18. Probability Punnett Square: bb B B Cross between: *Purebred recessive & *Purebred dominant

19. Probability Punnett Square: bb B BB B B B bb bb Cross between: *Purebred recessive & *Purebred dominant Produces: *Offspring that are all hybrids

20. Probability Punnett Square: bB b B Cross between: *Hybrid & Hybrid

21. Probability Punnett Square: bB b B Cross between: *Hybrid & Hybrid Produces: *Offspring possibilities 2 hybrids, 1 purebred dominant, and 1 purebred recessive B b B B B b b b

22. Punnett Square 1.Cross a homozygous dominant with a heterozygous organism 2.Cross a heterozygous organism with a homozygous recessive 3.Cross a homozygous recessive with a homozygous dominant 4.Cross a homozygous recessive with a homozygous recessive

23. Punnett Square (examples)

24. Genetic Survey TraitMaleFemaleTotal Hair(Black)_______________ (Brown)_______________ (Blonde)_______________ (Red)_______________ Eyes(brown)_______________ (hazel)_______________ (blue)_______________ Tongue(roller)_______________ (non-roller)_______________ Ear lobe(attached)_______________ (not attached)______________