1. Notes: Genetics

2. What is Genetics? Genetics = the scientific study of heredity how traits r passed from parents 2 offspring Offspring - the children or young of a particular parent

3. What is a Trait? Trait = characteristic that an org can pass thru its genes (ex. eye color) Genes = a segment of DNA on a chromosome that codes 4 a certain trait

4. Heredity Activity http://www.phschoo l.com/atschool/calif ornia/science_explo rer/life_science/Stu dent_Area/FLS_SC 3_ACT_index.htmlwww.phschoo l.com/atschool/calif ornia/science_explo rer/life_science/Stu dent_Area/FLS_SC 3_ACT_index.html

5. Dominant TraitRecessive Trait Free earlobesAttached earlobes Hair on fingersNo hair on fingers Widow's peakNo widow's peak Curly hairStraight hair Cleft chinSmooth chin Smile dimplesNo smile dimples Heredity Activity

6. What is an Allele? Allele = the diff forms of a gene (dominant & recessive) Dominant = trait ALWAYS shows up when present Recessive – trait masked (hidden) when a dominant allele is present

7. Who is Gregor Mendel?

8. Gregor Mendel “Father of Genetics” Due to his study of heredity/genetics using pea plants Young European priest Through experimentation Mendel discovered that one inheritable trait would always be dominant to its recessive alternative.

9. Mendel’s Experiment

10. Mendel’s Pea Plants P generation - Parental generation; organisms w/different genotypes mated to produce hybrids F1 generation (1 st filial generation) – the hybrid offspring of the P generation F2 generation (2 nd filial generation) – the hybrid offspring of the F1 generation

11. Mendel’s Pea Plants (continued) Parent generation Tall pea plant (TT) x Short pea plant (tt) F1 generation Tall pea plant (Tt) x Tall (Tt) pea plant F2 generation Tall pea plant(TT)/Tall pea plant (Tt)/ Tall pea plant (Tt)/Short pea plant (tt)

12. Some New Vocabulary Filial comes from the Latin word “filius” meaning son of Purebred pure; same traits (ex. Tall (TT) x Short (tt)) Hybrid mixed; different traits (ex. Tt x (tt)

13. Example 1 B = Dominant = Black fur = BB or Bb b = recessive = white fur = bb Male BB x female bb bb BBbBb4/4 = black fur BBbBb100% black fur

14. Example 2 B = Dominant = Black fur = BB or Bb B = recessive = white fur = bb Male Bb x female bb bb BBbBb2/4 = ½ black fur bbbbb2/4 = ½ white fur 50% black fur & 50% white fur

15. Dominant or Recessive? Tt BB qq Gg Rr Ff SS

16. Genotypes and Phenotypes Genotypes & Phenotypes Geno = traits that r NOT visible (ex. TT, Tt, tt) Pheno = traits that r VISIBLE; physical appearance (ex. tall or short)

17. Genotype or Phenotype? tall BB Round eyes Gg Brown fur Red hair SS

18. Homozygous or Heterozygous? Homozygous & heterozygous Homozygous = 2 identical copies of the gene for a trait (homo=same) Homozygous dominant = TT Homozygous recessive = tt Heterozygous = a different version of the gene (hetero=different) Heterozygous = Tt

19. Heterozygous or Homozygous? Tt BB qq Gg Rr Ff SS