biology chapter 12

Terms & Concepts: Appreciate the significance of the experiments of Griffith and Avery using transformation in bacteria. Understand that these experiments opened the door to our understanding of DNA as the genetic material. Be able to describe the experiments of Hershey and Chase. Know the general life cycle of the bacteriophage and its relationship to the E.coli bacterium. Understand how this experiment relied on radioactive markers to follow the transmission of DNA from phase to bacteria. Know that the basic building block of the DNA molecule are the four nucleotides. Be sure you can recognize a diagram of a nucleotide and its component parts: the phosphate group, deoxyribose sugar, and the nitrogenous bases. Appreciate the how the work of Chargaff and Franklin helped other scientist determine the base pairing of nucleotides and the 3D shape of the DNA molecule. Understand that the model proposed by Watson and Crick dependent not only on their work but that of other scientists. Appreciate that their model of DNA structure also led to our understanding of how genes work at the molecular level.

B. Read pages 295-299. Due 20/21 May.
Terms & Concepts: Be able to describe some of the important differences of the DNA molecule in prokaryotes and eukaryotes in terms of its location, size, and the function of histone proteins. Know the components of chromatin and its relationship to the eukaryotic chromosome. Understand why DNA must be able to replicate during mitosis and meiosis with a high degree of accuracy. Use the diagram on page 298 to visualize the process of DNA replication. Appreciate that this process requires the coordinated activity of many enzymes and other proteins including DNA polymerase.

Questions page 296: Read the "Analyzing Data" section on page 296 and write out the answers to the three questions in that section.

D. Read pages 300-306. Due 28 May.
Terms & Concepts: Be able to describe the general structure and function of the three major types of RNA, messenger, ribosomal, and transfer RNAs. Be able to compare the structure of RNA to that of DNA; know the similarities and the differences. Appreciate that the process of going from DNA (genotype) to a protein (phenotype) is a two step process, transcription and translation. Use the diagram on page 301 to visualize transcription. Be aware of the general similarity of this process to DNA replication. Be particularly aware of the role of RNA polymerase in this process and that the end product is mRNA. Be able to interpret the codons of mRNA into the corresponding sequence of amino acids in the resulting protein. Use the genetic code chart on page 303 for this purpose. Understand that in eukaryotes, mRNA often contains none coding sequences of base called introns as well as the coding sections, exons. Use the diagram on pages 304 and 305 to visualize the process of translation. Be sure you can describe the role of the ribosomes, mRNA, and tRNA in this process. Understand the relationship between the codons on the mRNA and the anticodons on the tRNA in terms of the placement of amino acids into the correct sequence.

E. Read page 307-312. Due 1 June.
Terms & Concepts: Be aware that mutations are an important source of genetic variation in populations and play a crucial role in evolution. Be able to list and describe different types of mutations such as point mutations and frame shift mutations. You will be required to predict how a mutation modifies the mRNA during transcription and the amino acid sequence of a protein during translation. Appreciate that genes do not work in isolation. They are dependent on their environment. Regulation allows genes to respond to changes in their environment and permits the cell and/or organism to adapt to environment. Be able to describe examples of gene regulation. In particular be able to describe the structure and function of the lac operon in bacteria and the promoter sequences and hox genes of eukaryotes.

Chapter 12, DNA and RNA