Genetics Chapters 13-15

Mitosis Two identical daughter cells Interphase Cell growth, preparing for cell division Prophase Metaphase Anaphase Telophase Cytokinesis

Mitosis Karyotype: picture of the chromosomes Chromatids (sister): 2 halves joined by a centromere Homologous chromosomes Matched pair of chromosomes

Meiosis 2 successive rounds No replication of DNA between them Meiosis I Half the number of chromosomes Meiosis II 4 haploid cells

Synapsis: homologous chromosomes pair Crossing-over: Homologues exchange information Nondisjunction: Failure to separate properly Down syndrome, Turner syndrome

Mendel Genetics:Study of heredity Genotype Phenotype Alleles: two alternate forms of the character Dominant Recessive F1(first filial generation) F2(second filial generation)

Mendel’s laws of heredity Law of Segregation: Alternate alleles separate Law of Independent Assortment: Genes located on different chromosomes

Mendel Mononhybrid: Heterozygous one trait Dihybrid: Heterozygous two traits Testcross

Not Mendel Polygenes Additive effect Pleiotropy Allele-more than one effect on phenotype Sickle cell, cystic fibrosis

Not Mendel Incomplete dominance Environmental effects Epistasis One gene interferes with the expression of another gene Codominance ABO blood types

Pedigree

Sex-linked Mom passes on X-chromosome to son Hemophilia Color-blindness DMD

Human chromosomes 23 pairs 22 autosomes 1 sex chromosome pair XX female XY male