1. Basic DNA and Genetics

2. Basic (like Elaine) DNA
Double helix shape (Rosalind Franklin, Watson and Crick)
DNA is wound around histone proteins to form chromatin
During replication, supercoiling occurs
Replication occurs during S phase of cell growth
Leading strand and lagging strand
Built 5’ to 3’ end

3. Replication in Depth
DNA is first unwound at replication forks by helicase
Stabilized by SSBPs
Nucleotides are brought in to match template strands
Arrive as nucleosides (DNA bases with triphosphate)
Bound to the parent strand by DNA Polymerase III
Can only add to 3’ end, so the strand grows from 5’ to 3’
Leading strand vs. Lagging strand
Okazaki fragments and ligase
DNA polymerase III can only add to existing: need RNA primer
Primase
Primers removed by DNA Polymerase I

7. Replication in Depth Telomeres are expendable, non-coding ends
Telomerase (application to cancer)
Though DNA pairs are matched pyramidine to purine, errors can occur, resulting in mutations
Checked by DNA Polymerase I, but can fail
End daughter cells both have same number of chromosomes as parent in MITOSIS (different in meiosis)
Diploid vs. Haploid – alternation of generations

10. Genetics Gregor Mendel Genotype vs. Phenotype Punnett Squrrr
Pea plants – good choice
Crossed true-breeding parents (P)
Crossed F1 generation again
Noted masked traits resurfaced in the F2 generation
Dominant vs. Recessive Allele
Genotype vs. Phenotype
Punnett Squrrr

13. Genetics Test Cross Mendel’s Laws of Segregation
Determine genotype of a organism by crossing the dominant phenotype with a homozygous recessive
Mendel’s Laws of Segregation
#1 – Law of Segregation
When gametes are produced, homologous chromosomes separate
Created by meiosis I
Monohybrid crosses
#2 – Independent Assortment
Each pair of alleles segregates into gametes independently
Created by Meiosis I
Dihybrid crosses (or more than 2 traits)

14. Human Genetics Pedigrees
Diseases are recessive -> non-functioning protein (or lack of)
Heterozygotes for the trait are referred to as “carriers” CF
Extracellular buildup of Cl- ions, resulting in thick mucus
Percussive treatment
Tay-Sachs
“Hitler’s Revenge”
Enzyme that breaks down lipids in the brain is non-functional

15. Human Genetics Sickle Cell Anemia
African Americans are primary afflicted
Substitution in hemoglobin causes crystallization
Pleiotropic
Heterozygote advantage