BIOL 3315 1st Edition Lecture 4 Outline of Last Lecture Chapter 1 (continue)I. Impact on human geneticsII. Predictive Preventative MedicineIII. Genetic and human affairsIV. Social issue and geneticsChapter 2I. OverviewII. What is hereditary material?III. Chargaff’ rulesIV. The DNA nucleotideV. X-ray diffraction patterns of DNAVI. The Double HelixVII. Denaturing DNAVIII. Structure and function: three roles of DNAIX. DNAX. Nature of genomesXI. Prokaryotic genomesXII. Viral genomesXIII. Gene neighborhoodsXIV. Repetitive DNAXV. Reassociation curve of complex genomesXVI. Structure of genesXVII. Eukaryote Gene XVIII. Eukaryote protein-coding genesOutline of Current Lecture XIX. “C-value paradox”XX. Why are some genomes so largeXXI. Eukaryotic nuclear genomesXXII. Eukaryotic chromosomesXXIII. Eukaryotic chromosomesXXIV. Chromosomes of 2 tomatoXXV. Nuclear DNAXXVI. Comparative genomicThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.XXVII. X chromosomes in 3 species Current LectureXIX. Comparing genome size and complexity the “C- value paradox”A. Genome size does not correlate with organismal complexityXX. Why are some genomes so large?A. There is no clear correlation between genome size and genetic complexityB. C-value- the total amount of DNA in the genome (per haploid set of chromosomes)C. C-value paradox- the lack of relationship between the DNA content (C-value) of an organism and its coding potential XXI. Eukaryotic nuclear genomesA. Each species has characteristic chromosome numberB. Genes are segments of nuclear chromosomesC. Ploidy refers to number of complete sets of chromosomes1. Haploid (1n) one complete set of genes2. Diploid (2n)3. Polyploid (≥ 3n)D. In diploid, chromosomes come in homologous pairs (homologs)1. Structurally similar2. Same sequence of genes3. Many contain different allelesE. What is n for humans? 23 F. How many chromosomes in somatic cells? 46G. In humans, somatic cells have 2n=46 chromosomesXXII. Eukaryotic chromosomes (1)A. Cytogenetic: microscopic study ofchromosomesB. Considerable difference in sizeand number of genesC. Variable centromere position1. Telocentric: centromere atend2. Acrocentric: centromere close to end3. Metacentric: centromere in middle4. P arm is shortest, q arm is longest D. Telomere: end of chromosome (important in aging)E. Centromere: constriction1. Attachment pointXXIII. Eukaryotic chromosomesA. Heterochromatin1. Densely stained regions of highly compact DNA2. Mostly repetitive sequencesB. Euchromatin: poorly stained, less compact, contain transcribed genes (contain active part of genome)C. Binding patterns (metaphase chromosomes1. Differential uptake of dyes2. G bands, Giemsa stain (A/T rich)3. R bands reverse of Giesma (G/C rich)D. Polytene chromosomes (present in fruit flies but not us)1. Replicated, un-separated chromosomes2. Present in certain tissues of dipteran insectsXXIV. Chromosome of 2 tomatoA. Nucleolus organizerB. One to many per eukaryotic genomeC. Lead to formation of nucleolusD. Contain rRNA genes copies essential for ribosomal XXV. Nuclear DNAA. Highly organized, various degrees of coilingB. Nucleosome1. Fundamental unit of chromatin2. DNA wound around histone core( octamer)a. Histones are highly conserved proteins b. *H2A, H2B, H3,H43. 10nm fiber4. Solenoid, 30nm fiberC. Higher order coiling1. Solenoid loops attach a scaffold2. Scaffold attachment contain topoisomerase II3. Form larger diameter fibers XXVI. Comparative genomic A. Study of similarities and differences among genomesB. Many genes are shared among all living things or between related groupsC. Study of genes in model organisms provides useful information regarding genes in other organismsD. Large genome projects produce considerable information1. Computer analysis XXVII. X chromosome in 3 speciesA. Synteny-blocks of same genes occur in same order on chromosomes of different