Lecture, chapter 9 - From genes to proteins

Today we finished chapter 9, from genes to proteins.

We talked about translation, protein structure, and the possible modifications that a polypeptide can undergo after it has been synthesized (by translation). We also discussed the difference between a polypeptide and a protein (when there is one).

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Lab 05 - Heritability and quantitative traits

Today we did our lab in heritability, a calculation that can be done when dealing with quantitative traits.

Heritability: The proportion of phenotypic variation explained by genotypic variation (as opposed to environmental factors)

Broad sense heritability (H^2): Heritability taking into account all kinds of genetic interactions (additive effects of polygenes, epistasis, dominance-recessiveness, etc.)

We used finger print ridge count data to calculate the broad sense heritability of the trait. Every student took his/her own fingerprints and did a ridge count on each one. We pooled everybody's data and proceeded with the calculation.

Narrow sense heritability (h^2): Heritability taking into account only the additive effects of polygenes. This measure is of interest to individuals who are interested in selection programs with the goal of shaping a population according to their interests (e.g. farmers or cattle breeders).

We used height data from students, their parents, aunts and uncles, and siblings, to calculate h^2 in a human population (even though this is never done with any practical purposes).

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Lecture, chapter 8 - DNA structure and chromosomal organizationLecture, chapter 9 - From genes to proteins

Today we finished chapter 8. We focused on DNA replication and the differences on how the leading and the lagging strands are synthesized in the process.

We also started chapter 9, on transcription and translation.

We covered the transcription process at a basic level, touching on its three stages (initiation, elongation, termination) and the role of different DNA sequences (promoter, gene [narrowly defined], terminator) in the process. Then we discussed mRNA processing (5'-capping, polyadenylation)

Tomorrow: For our heritability lab please know your height. Also find out about your siblings, parents, and grandparents' heights. All heights must be provided in inches.

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Lecture, chapter 8 - DNA structure and chromosomal organization

Today we covered most of chapter 8, on DNA structure and chromosomal organization.

We reviewed a brief time line of discoveries that lead us o know what we now know about nucleic acids, from the discovery of nuclein to the structure of DNA, for which Crick, Watson, and Wilkins received the Nobel prize in 1962. We remembered the important role that Rosalind Franklin played on the discovery of the DNA double helix, and how Watson neglected to acknowledge her properly (as well as the committee in charge of awarding the Nobel prize).

We compared the basic differences between DNA and RNA, introduced important concepts to comprehend nucleic acid lingo, and discussed the basics of the mechanisms in place for a cell to supercoil DNA into densely packed chromosomes visible during metafase in cell division.

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