Instructor Resources for Chapter 1: Heritable Material
|PowerPoint Slides with Pedagogy for Each Section in Chapter 1|
These slides have pedagogy built into them. These slides are structured to not only cover the content, but also engage students in thoughtful discussion, questioning and interpreting data. Instructors can use these slides directly, or modify them to suit their pedagogical needs.
Bio-Math Exploration 1.1: Why do amino acids make a better code than nucleotides?
ELSI 1.1: Who owns your DNA?
Bio-Math Exploration 1.2: How much DNA is in each band?
Bio-Math Exploration 1.3: How are generations measured on a log scale?
|Apply What You Know:
Optional Questions for Advanced Exploration of Chapter 1 Content
- When biological information is used by a cell, is it consumed or left intact? Answer this question while focusing on DNA. In future chapters, you might modify your answer as you learn about other forms of biological information.
- DNA is not consumed since it can be replicated and transcribed many times. It is possible that each use produces some new variation, but the original DNA template remains consistent. Epigenetic alterations can change the function of DNA, but the sequence remains unaltered.
- Search PubMed for the 2002 paper by Cooney, Dave, and Wolff. What do you learn about the ability of a mother to affect the epigenome of her offspring?
- Pregnant mice were fed methyl supplements to increase DNA methylation. Their offspring lived longer lives than control mice that did not receive the supplements.
- Now search PubMed for the 2003 paper by Rakyan, Chong, Champ, Cuthbert, Morgan, Luu, and Whitelaw. What other surprising news is there about the capacity of an epigenome to be passed on to the next generation?
- Altered methylation status of the gene Axin(Fu) can lead to a kinked tail in mice. This epigenetic regulation can be passed on to subsequent generations through both the father and the mother.
- Given the lessons from the papers you found in the previous two questions, what implications do these papers have on your environmental exposure to compounds that alter your methylation status? Keep in mind that changes in the epigenome are not dependent upon mutations in the DNA sequence.
- Anything we do to alter our epigenome can alter our own phenotypes and those of our offspring. Therefore, activities such as smoking and conditions such as obesity can transcend generations.
- Search PubMed for the 2007 paper by Levy, Sutton, Ng, et al. published in the open access journal PLoS Biology. Read the abstract to gain an appreciation for the variation within a single human’s genome. Based on this abstract, do you think DNA replication produces identical copies of DNA? Is the encoding of genetic information perfectly accurate, or do our DNA polymerases duplicate information inaccurately from one generation to the next?
- The investigators reported, "more than 4.1 million DNA variants, encompassing 12.3 Mb. These variants (of which 1,288,319 were novel) included 3,213,401 single nucleotide polymorphisms (SNPs), 53,823 block substitutions (2-206 bp), 292,102 heterozygous insertion/deletion events (indels)(1-571 bp), 559,473 homozygous indels (1-82,711 bp), 90 inversions, as well as numerous segmental duplications and copy number variation regions." Therefore, it is likely that DNA polymerases make errors with each generation. The paper by Roach et al. (2010) sequenced the genomes of two children and their parents to document how many mutations are passed on each generation.