Review Chapters 16 27 Chapter 16 Molecular Genetics

Review Chapters 16 -27

Chapter 16: Molecular Genetics �You Must Know: ◦ The structure of DNA ◦ The major steps in replication ◦ The difference between replication, transcription, and translation ◦ “Central Dogma” ◦ How DNA is packaged into a chromosome

Experiments: �Griffin �Hershey and Chase �Chargaff �Meselson-Stahl

DNA Structure

Replication

Proofreading and repair � Mismatch Repair ◦ A DNA polymerase this as soon as added ◦ other proteins do as well (they monitor) � Excision Repair ◦ enzyme nuclease cuts segment of strand containing damage ◦ resulting gap is filled (A DNA polymerase and DNA ligase) nucleotide is continually does this

DNA packing

Chapter 17: From Gene to Protein �You Must Know ◦ The key terms gene expression, transcription, and translation ◦ How to explain the process of transcription ◦ How eukaryotic cells modify RNA after transcription ◦ The steps to translation ◦ How point mutations can change the amino acid sequence of a protein

Translation

Chapter 18: Regulation of Gene Expression �You Must Know ◦ The functions of the three parts of an operon ◦ The role of repressor genes in operons ◦ The impact of DNA methylation and histone acetylation on gene expression ◦ The role of oncogenes, proto-oncogenes, and tumor suppressor genes in cancer

Operons

Eukaryotic Gene Expression

Chapter 19: Viruses �You Must Know ◦ The components of a virus ◦ The differences between lytic and lysogenic cycles

Structure �Capsid �Envelope �DNA or RNA

Replication

Information flow in cells can be regulated by various mechanisms. (a) Describe the role of THREE of the following in the regulation of protein synthesis: RNA splicing repressor proteins methylation si. RNA (b) Information flow can be altered by mutation. Describe THREE different types of mutations and their effect on protein synthesis. (c) Identify TWO environmental factors that increase the mutation rate in an organism, and discuss their effect on the genome of the organism. (d) Epigenetics is the study of heritable changes in the phenotype caused by mechanisms other than changes in the DNA sequence. Describe ONE example of epigenetic inheritance.

Chapter 20: DNA Technology and Genomics �You Must Know ◦ The terminology of biotechnology ◦ The steps in gene cloning with special attention to the biotechnology tools that make cloning possible ◦ The key ideas that make PCR possible ◦ How gel electrophoresis

Terminology �Genetic Engineering �Biotechnology �Recombinant DNA �Gene Cloning �Restriction Enzymes �Restriction sites �Restriction fragments �Sticky ends

Gene Cloning

PCR

Electrophoresis

4. The flow of genetic information from DNA to protein in eukaryotic cells is called the central dogma of biology. (a) Explain the role of each of the following in protein synthesis in eukaryotic cells. • RNA polymerase • Spliceosomes (sn. RNPs) • Codons • Ribosomes • t. RNA (b) Cells regulate both protein synthesis and protein activity. Discuss TWO specific mechanisms of protein regulation in eukaryotic cells. (c) The central dogma does not apply to some viruses.

Chapter 21 �“Variation in molecular units provides cells with a wider range of functions” �This chapter serves to connect genetics to evolution. �Illustrative examples listed for this chapter are: • Different types of hemoglobin • MHC proteins • Chlorophylls • Molecular diversity of antibodies in response to an antigen

Chapter 22: Descent with Modification �You Must Know ◦ Natural selection is a major mechanism of evolution ◦ Biological evolution is supported by scientific evidence from many disciplines, including math ◦ Graphical analysis of allele frequencies in a population ◦ Application of the Hardy-Weinberg equilibrium equation ◦ Graphical analyses of allele frequencies in a population ◦ Analysis of sequence data sets ◦ Analysis of phylogenetic trees ◦ Construction of phylogenetic trees based on

Evidence for evolution �Direct observations �The fossil record �Homology ◦ ◦ ◦ Homologous structures vs. Analogous Convergent evolution Embryonic homologies Vestigial organs Molecular homologies �Biogeography ◦ Continental drift ◦ Endemic species

Chapter 23: The Evolution of Populations �You Must Know ◦ How mutation and sexual reproduction each produce genetic variation ◦ The conditions for Hardy-Weinberg Equilibrium ◦ How to use the Hardy-Weinberg equation to calculate allelic frequencies and to test whether a population is evolving

Practice �Suppose in a plant population that red flowers (R) are dominant to white flowers (r). In a population of 500 individuals, 25% show the recessive phenotype. How many individuals would you expect to be homozygous dominant and heterozygous for this trait?

Some terms �Natural selection �Genetic drift ◦ Founder effect ◦ Bottleneck effect �Gene flow �Directional selection �Disruptive selection �Stabilizing selection �Heterozygote advantage

Chapter 24: The Origin of Species �You Must Know ◦ The difference between microevolution and macroevolution ◦ The biological concept of species ◦ Prezygotic and postzygotic barriers that maintain reproductive isolation in natural populations ◦ How allopatric and sympatric speciation are similar and different ◦ How an autopolyploid or an allopolyploid chromosomal change can lead to sympatric speciation ◦ How punctuated equilibrium and gradualism describe two different tempos of speciation

Pre and Post Zygotic Isolation �Habitat �Behavioral �Temporal �Mechanical �Gametic �Reduced Hybrid viability �Reduced Hybrid fertility �Hybrid Breakdown

Autopolyploid

Allopolyploid

Adaptive Radiation

3. Reproduction can be either asexual or sexual. (a) Using a specific example, describe how organisms can reproduce asexually. Discuss TWO evolutionary advantages of asexual reproduction. (b) Identify THREE ways that sexual reproduction increases genetic variability. For each, explain how it increases genetic diversity among the offspring. (c) Discuss TWO prezygotic isolating mechanisms that prevent hybridization between two species. Include in your discussion an example of each mechanism.

4. Phylogeny reflects the evolutionary history of organisms. (a) Discuss TWO mechanisms of speciation that lead to the development of separate species from a common ancestor. (b) Explain THREE methods that have been used to investigate the phylogeny of organisms. Describe a strength or weakness of each method. (c) The two phylogenetic trees represent the relationship of whales to six other mammals. All of the organisms shown have a pulley-shaped astragalus bone in the ankle except for the whale. • For each tree, describe a monophyletic group, the closest relative to the whale, and the point at which the pulley astragalus was lost or gained. • Based on the principle of parsimony (the simplest explanation is the best) and the genomic information in the table shown, identify which tree is the best representation of the evolutionary relationship of these animals, and justify your answer.

Chapter 25: The History of Life on Earth �You Must Know ◦ The age of the Earth and when prokaryotic and eukaryotic life emerged. ◦ Characteristics of the early planet and its atmosphere ◦ How Miller and Urey tested the Oparin. Haldane hypothesis and what they learned ◦ Methods used to date fossils and rocks ◦ Evidence for endosymbiosis ◦ How continental drift can explain the current distribution of species.

Chapter 26: Phylogeny and the Tree of Life �You Must Know ◦ The taxonomic categories and how they indicate relatedness ◦ How systematics is used to develop phylogenetic trees ◦ The three domains of life including their similarities and their differences

Phylogenies show evolutionary relationships

3. Phylogeny is the evolutionary history of a species. (a) The evolution of a species is dependent on changes in the genome of the species. Identify TWO mechanisms of genetic change, and explain how each affects genetic variation. (b) Based on the data in the table below, draw a phylogenetic tree that reflects the evolutionary relationships of the organisms based on the differences in their cytochrome c amino-acid sequences and explain the relationships of the organisms. Based on the data, identify which organism is most closely related to the chicken and explain your choice. (c) Describe TWO types of evidence—other than the comparison of proteins —that can be used to determine the phylogeny of organisms. Discuss one strength of each type of evidence you described.

Three Domains Characteristic Bacteria Archaea Eukarya Nuclear Envelop No No Yes Membrane-enclosed organelles No No Yes Introns No Yes Histone proteins assoc. with DNA Circular chromosome No Yes Yes No

Chapter 27: Bacteria �You Must Know: ◦ Electrophoresis ◦ Plasmid-based transformation ◦ Restriction enzyme analysis of DNA