TheMcGraw-HillCompaniesChapter 9MicrobialGeneticsFoundationsinMicrobiologyEIGHTHEDTTIOKathleenParkTalaroBarryChessCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display
Chapter 9 Microbial Genetics Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display
Genetics andGenesGenetics - the study of heredityThe science of genetics explores:1. Transmission of biological traits from parent tooffspring2.Expression and variation of those traits3.Structure and function of genetic material4.How this material changes2
2 Genetics and Genes Genetics – the study of heredity The science of genetics explores: 1. Transmission of biological traits from parent to offspring 2. Expression and variation of those traits 3. Structure and function of genetic material 4. How this material changes
Levels ofStructureandFunctionoftheGenomeGenome - sum total of genetic material of a cell(chromosomes + mitochondria/chloroplasts and/or plasmids)- Genome of cells -DNA- Genome of viruses - DNA or RNADNA complexed with protein constitutes the genetic materialas chromosomesCopyright The McGraw-Hil Companies, Inc. Permission required for reproduction or dis playCell levelOrganism levelChromosome levelMolecular levelTAGCCGTATAGCGCCC
3 Levels of Structure and Function of the Genome • Genome – sum total of genetic material of a cell (chromosomes + mitochondria/chloroplasts and/or plasmids) – Genome of cells – DNA – Genome of viruses – DNA or RNA • DNA complexed with protein constitutes the genetic material as chromosomes T T GC A CG TA T CG GC CG T A G C C G C A A A A T C G Organism level Cell level Chromosome level Molecular level Copyright © The McGraw -Hill Companies, Inc. Permission required for reproduction or display. © PhotoLink/Photodisc/Getty Images RF
MicrobialGenomesBacterial chromosomes are a single circular loopEukaryotic chromosomes are multiple and linearCopyright The McGraw-HillCompanies, Inc. Permission required for reproduction or displayCellsProkaryoteEukaryote(composite)-Chromosomes-NucleusNucleolusChromosomePlasmidsMitochondrionPlasmid(insomeVirusesfungi and迷protozoa)ExtrachromosomalDNARNADNAChloroplast4
4 • Bacterial chromosomes are a single circular loop • Eukaryotic chromosomes are multiple and linear Microbial Genomes Chromosomes Nucleus Mitochondrion Nucleolus Extrachromosomal DNA Chloroplast Chromosome Plasmids DNA RNA Plasmid (in some fungi and protozoa) Cells Prokaryote Viruses Eukaryote (composite) Copyright © The McGraw -Hill Companies, Inc. Permission required for reproduction or display
GenesChromosome is subdivided into genes, the fundamental unit ofheredity responsible fora giventraitSite on the chromosome that provides information for acertain cell functionSegment of DNA that contains the necessary code tomake a protein or RNA moleculeThree basic categories of genes:1.Genes that code for proteins - structural genes2.Genes that code for RNA3.Genes that control gene expression - regulatory genes5
5 Chromosome is subdivided into genes, the fundamental unit of heredity responsible for a given trait – Site on the chromosome that provides information for a certain cell function – Segment of DNA that contains the necessary code to make a protein or RNA molecule Three basic categories of genes: 1. Genes that code for proteins – structural genes 2. Genes that code for RNA 3. Genes that control gene expression – regulatory genes Genes