Chapters 1 and 2 Introduction and Genome Structure
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Genetics
Chapter 1 is designed to convince you that you won’t do well in genetics.
Read it, because it has some good refresher terms.
(Race through slides) Discontinous, continuous. Environmental effects,
(emphasize its confusing as presented)
(But read it like a nova episode. Sit back and let it wash over you. Let you mind wander on
it.)
(Stop on Albinism)
Why do simple genetics problems sometimes seem difficult?
1st reason) Two fields of study, Mendelian and Molecular?
Breeders
vs
Molecular
Started with Cows with bigger utters, plants with more fruit. Whole field with its own
terms developed this way
Now genes and phenotypes are explained in molecular terms. And they have their
own language
We have to recognize and understand when two different fields, even though they
are using two different terms, are talking about the same thing .
(go to kingdom/cellt ype slide)
2nd reason) Different organisms reproduce differently?
Yet books hop from one organism to another because each one has some “special”
(bizarre) feature that makes it useful for us to see what’s going on.
We learn us
Animals Eukaryotic Diploid
Fungi Eukaryotic Haploid
Bacteria Prokaryotic Haploid
Plants Eukaryotic (Polyploid?) but kind of like animals
Would be best/easiest to have animal genetics class a fungal genetics class a prok
genetics class and bacterial genetics class….
So learnone of em… maybe the animals for this class. And then elegantly request to be
reminded of how the other organisms work. I know animals would be so and so…. But
remind… does that happen in fungi?
Its knowing the stupid trick about the reproduction of the organism that often makes
it easy.
Genomes: one complete set of the organism’s DNA
DNA is the genetic material
What the Transforming factor?
Most figured protein.” Binary letters vs the alpabet “
Griffith 1928
(Draw)
Avery 1944
DNA structure (go to slides) of structure
Sugar Phosphate Bases
(Draw as base pairs)
draw
5’-3’Antiparallel
5’____________3’ 5’ATCGATCGATCG3’
3’____________5’ 3’TAGCTAGCTAGC3’
wound 10 bp/turn
smart for information storage
back up copy of information.
But not redundant
accessible
linked winding (pro and con)
Gene structure
Prokaryotic
Operons
Closely spaced genes
Eukaryotic
Introns/Exons
Lots of repetitive “space”
(Draw& label)
(slides)
Genomes Structure
Prokaryotic
Circular
4 million base pairs
Eukaryotic
Multiple linear chromosomes
Larger 3 billion base pairs
Ploidy
Homologous
Correlations (slides)
Exon number roughly increases with genome size
But gene number doesn’t increase with genome size at same rate
Chromosome number doesn’t show much info
(Slides)
Eukaryotic structure/cytogenetics
Centromere positioning
“p”s and “q”s
Nucleoli/Nuclear organizers
Chromomeres/knobs
Heterochromatin/Euchromatin
Banding G and R bands
(draw and label)
Eukaryotic packaging
Histones, nucleosomes, solenoid, scaffolding, SARs, supercoiled scaffold
(Draw and label)
(movie slide)