INTRODUCTION TO GENETICS

1. INTRODUCTION TO GENETICS • The science of inheritance • Parents and offspring • heredity is the set of characteristics an organism receives from his parents

2. INTRODUCTION TO GENETICS

3. INTRODUCTION TO GENETICS • Gregor Mendel • worked with peas • discovered 7 traits in true breeding pea plants • F1 generation • F2 generation

4. INTRODUCTION TO GENETICS • Gene functional unit that controls inherited trait expression that is passed on from one generation to the next • Dominant allele a specific trait that appears in the F1 generation • Denoted with a capital letter

5. INTRODUCTION TO GENETICS • Recessive allele a specific trait that is masked in the F1 generation • Denoted with a small letter • Homozygous organism with two of the same alleles for a specific trait

6. INTRODUCTION TO GENETICS • Heterozygous organism with two different alleles for a specific trait • Hybrid organism heterozygous for a specific trait

7. INTRODUCTION TO GENETICS

8. INTRODUCTION TO GENETICS • Segregation • A process that separates the two alleles • Independent assortment

9. INTRODUCTION TO GENETICS • Mendel’s principles • individual units, called genes, determine biological characteristics • For each gene, an organism receives one allele from each parent.

10. INTRODUCTION TO GENETICS • if an organism inherits different alleles for the same trait, one allele may be dominant over the other • some genes segregate independently

11. INTRODUCTION TO GENETICS • TURN AND TALK Explain dominance, segregation, and independent assortment.

12. INTRODUCTION TO GENETICS • Meiosis • Chromosomes • Forming gametes • haploid and diploid cells • Haploid having one copy of each chromosome • Diploid having two copies of each chromosome

13. INTRODUCTION TO GENETICS • Phases of meiosis • Have students reproduce chart on pg 133 of book. • Meiosis and genetic diversity • chromosome combinations (pg 134 in book)

14. INTRODUCTION TO GENETICS • Crossing over exchange of chromosomal segments between a pair of homologous chromosomes during prophase I

15. INTRODUCTION TO GENETICS • TURN AND TALK Explain how crossing over increases genetic diversity.

16. INTRODUCTION TO GENETICS • Analyzing inheritance • Probability • Probability and genetics

17. INTRODUCTION TO GENETICS • A closer look at heredity • Incomplete dominance complex heritance pattern in which the heterozygous phenotype is intermediate between two heterozygous parents

18. INTRODUCTION TO GENETICS • Co-dominance complex inheritance pattern that occurs when neither allele is dominant and both alleles are expressed

19. INTRODUCTION TO GENETICS • Polygenic traits characteristic, such as eye color or skin color, that results from the interaction of multiple gene pairs