Chapter 1 Introduction

Branches of Genetics 4. Quantitative genetics 1. Transmission genetics Classical or Mendelian genetics 2. Molecular genetics chromosomes, DNA, regulation of gene expression recombinant DNA, biotechnology, bioinformatics, genomics, proteomics Population, evolutionary genetics allelic frequencies in populations effects of migration study relatedness of taxa via DNA and protein analysis 4. Quantitative genetics effects of many genes

What is a gene? A unit of inheritance A specific location on a chromosome A sequence of base pairs Transcribed into mRNA Encodes a protein Expressed The specifier of a phenotype Composed of DNA

Model Organisms cheap to grow short generation time can control mating no ethical concerns many offspring some have simpler systems small (most)

Why use model organisms? Development Disease Metabolic pathways (biochemistry) Evolution All living organisms share a common descent

Prokaryotic model organism Bacteria E. coli

Eukaryotic model organism 1. Unicellular Saccharomyces cerevisiae Bakers yeast Chlamydomonas reinhardtii Green algae

2. Multicellular Neurospora crassa C. elegans Orange bread mold Nematode worm 1mm long, 959 cells, transparent

transparent development Xenopus laevis big eggs Zebra danio transparent development http://www.biology.uiowa.edu/faculty_info.php?ID=1120 .

Arabidopsis thaliana small plant/mustard family Drosophila melanogaster Fruit fly Mus musculus