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

INTRODUCTION TO GENETICS

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

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

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

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

INTRODUCTION TO GENETICS

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

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

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

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

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

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)

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

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

INTRODUCTION TO GENETICS Analyzing inheritance Probability Probability and genetics

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

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

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