Lecture, chapter 8 - DNA structure

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Rosalind Franklin and her "photo 51"
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Today we started covering chapter 8, on the structure of DNA and chromosomes.

We talked about a little bit of the history of how the structure of DNA was discovered, including the injustice commited towards Rosalind Franklin, who took the X-ray diffraction image known as "photo 51", which was key for Watson and Crick to resolve the structure of the double helix. Her collaborator, Maurice Wilkins showed Watson the picture, without Franklin's knowledge, and the latter failed to acknowledge the fact that HER image put him and Crick on the road to become the icons they officially are today.

Then we talked about the structure of nucleotides and how they are assembled to form the famous DNA double helix.

On Thursday: We will talk about the similarities and differences between DNA and RNA, and will cover the basics of chromosome structure.

Congratulations to Brittany Simmons, the winner of the heritability challenge...!

Have a happy Easter break!

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Lab 05 - Heritability

In today's lab we focused in calculating heritability, the proportion of phenotypic variance explained by genetic differences.

We covered two approaches to calculating heritability:

1. Broad sense heritability: It reflects all possible genetic contributions to a population's phenotypic variance like effects due to allelic variation (additive variance), dominance, or polygenic interactions, as well as matrenal and paternal effects.
2. Narrow sense heritability: It quantifies the proportion of phenotypic variation explained by allelic variation.

We calculated broad sense heritability with data collected from student's fingerprints, specifically total ridge count. And narrow sense heritability will be calculated based on students' heights in inches, as well as the heights of their siblings, parents, and parents siblings.

The heritability challenge (Thursday):

During the exercise I made a mistake when calculating broad sense heritability. Apparently no body caught it. If you can find the mistake and explain the whole exercise correctly to the rest of the class, you will have the chance to earn 5 bonus points. Be prepared, and among those who have the answer I will randomly chose some one to try to get the bonus points.

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Friday, April 3, 2009

EXAM 1

We had our first exam, covering chapters 1 through 6 in the book.

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