BIOL 1005 Action Center – Before Exam 2 Work together with your peers on each of these tasks, which are designed to help you organize all of the information that you have learned in this section of the course. Try not to use your notes unless everyone in your group is at a loss; instead, see if you can figure out each problem based on what you know. Don’t rush! The idea is to make sure you understand. 1. Grasp the Big Picture Directions: The concept map at upper right is one way to organize much of the information we have covered in this section of the course. On a separate piece of paper, write a sentence or two to answer each of the 7 questions in the concept map. [NOTE: For #6 on the map, you can answer the question for viruses, but we haven’t done biotechnology yet; we will do so before exam 2]. 2. Pay Attention to Scale Directions: Arrange the following terms in order from smallest to largest: cell nucleus, adenine, codon, gene, zygote, nitrogen atom, tRNA, chromosome, proton, gamete. Explain each choice you make. 3. Make a Sketch (or Two) Directions: On a separate piece of paper, draw a big cell containing DNA with the following sequence: TACGTTGCTACCCCCACT. Sketch the events of protein synthesis, including the role of DNA, mRNA, tRNA, amino acids, and the ribosome. (You may also use the magnets on the white board for this purpose.) What sequence of amino acids corresponds to the gene? (Use the dictionary of the genetic code in your book.) Now pretend the cell is a helper T cell and it is infected with HIV. Suppose the sequence of HIV’s genetic material is CCCAGCCUC. Sketch what happens upon infection with HIV, starting with attachment and ending with the release of new HIV particles. 4. Move Some Chromosomes Use the paper chromosomes left over from lab to demonstrate and talk through the events of mitosis and of meiosis. (If you are doing this at home, you can make your own chromosomes.) You can also search the internet for photos or illustrations of each stage of mitosis and meiosis, and move your chromosomes to follow along. Before you begin, ask yourself these questions: • Do you understand how to identify homologous chromosomes? • Do you understand the relationship between the two chromatids that make up a replicated chromosome? • Can you identify what happens in interphase, cytokinesis, and in each stage of mitosis or meiosis? 5. Sort These Words or Put ‘Em in a Concept Map Directions: Define each of the following terms. Then, on a separate piece of paper, place them into categories – you get to decide on the categories yourself. Alternatively, you may choose to make a concept map using these terms. DNA metaphase cell nucleus chromosome interphase centromere tRNA genotype ribosome amino acid heterozygous anaphase codominance ATP protein terminator nucleotide RNA polymerase gene gamete virus chromatid mitosis haploid translation incomplete dominance homozygous telophase egg cell reverse transcriptase mutation codon mRNA genetic code zygote sperm cell cytokinesis anticodon DNA replication allele transcription enzyme DNA polymerase promoter phenotype prophase HIV meiosis cell diploid X inactivation sex chromosomes 6. Make a Flowchart (or Write a Paragraph) Directions: On a separate piece of paper, make a flowchart or write a paragraph that explains how exposure to sunlight could lead to skin cancer. Use the following terms (plus whatever other words you find necessary): Cancer, cells, DNA, gene, malignant, mitosis, protein, radiation, tumor, mutation 7. Predict Some Babies Directions: On a separate piece of paper, explain the relationship between a Punnett square and the events of meiosis. Then, use Punnett squares to predict the probabilities of each of the possible genotypes and phenotypes of the offspring in each of the following crosses. [See the How to Solve a Genetics Problem section in your textbook for help.] -­‐ Mom and dad are both symptomless carriers of cystic fibrosis (recessive allele) -­‐ Mom has blood type A and is homozygous; dad has blood type B and is heterozygous -­‐ Mom is a carrier of hemophilia (X-­‐linked, recessive); dad doesn’t have hemophilia 8. Make a Couple of Charts Directions: On a separate piece of paper, make charts that list the similarities and differences between: DNA replication, transcription, and translation; bacterial cells and viruses; binary fission, mitosis, and meiosis 9. Learn from Videos Directions: On the iPads or your own computer, look at a few Khan Academy videos. Don’t just be a passive watcher! After each video, use diagrams and your own words to summarize what you saw. • Protein synthesis: Science à Biology à Evolution and natural selection à DNA • Viruses: Science à Biology à Tree of life à Viruses • Videos on chromosomes, cell division, and cancer: Science à Biology à Cells and cell division