Law of segregation allele pairs segregate during

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Law of Segregation: allele pairs segregate during gamete formation and paired condition is restored by the random fusion of gametes at fertilization- Ex: Mendel selecting pure bred pea varieties with either spherical seeds or dented seeds -Law of Independent Assortment: the segregation of each allele pair is independent of other allele pairs; the individual allele pairs need to be located on separate loci, far from each other to allow independent assortment during gamete formation- Ex: Dihybrid cross -2. Know how to do Punnett Square -3. Non-Mendelian patterns of inheritance and examples -Intermediate inheritance/incomplete dominance: Red x White = Pink -Codominance: Red + White -Pleiotropy: Phenylketonuria -Epistasis: Male pattern baldness -Multiple Genes: skin color -Sex-Linked Inheritance: hemophilia -Maternal inheritance: stem coloration in four o’clock plants -Environmental Effect on Gene Expression: skin color based on sun Ch. 14 DNA Structure and Replication -1. Experiments -DNA as genetic material- Griffin -S-strain(disease-causing) + R-strain(rough) -heat killed S= no disease; heat killed S + R= disease -DNA as semiconservative- Menselson + Stahl -semiconservative= half of new DNA is old template -Sample 1: 14N + 15N Separate -Sample 2: 14N + 15N Hybrid -Sample 3: Hybrid + 14N -2. Structure of DNA double helix -1. 2 strands H-bonded together w/ 2nm width -2. strands turn right -> right-handed helix (clockwise); ladder- strands as ropes w/ bases as rungs -3. hydrophilic sugar-phosphate on outside of helix- makes DNA soluble -4. hydrophobic N-bases stacked perpendicular to strand; .34 nm b/w base pairs; 10 base pairs per turn -5. A-T (2 H-bonds), G-C (3 H-bonds)- complementary base pairing- Chargaff’s rule -6. 2 strands run in opposite directions; P group attached @ 5th C of 5’ ribose, OH group attached @ 3rd C of 3’ ribose -3. Complementary base pairing- G-C and A-T -3 different forms of DNA -A-DNA- dehydrated form -B-DNA- most common
-Z-DNA- short oligonucleotides GCGCGC -4. Enzymes + Proteins involved in DNA replication, roles, + sequence in DNA replication process -Initiation -supercoiling relaxed @ origin of replication (ORI) by topoisomerase-Relaxed DNA helix opened to make replication fork by helicase-resulting single stranded DNA stabilized by single stranded DNA binding (SSB) proteins-Primasemakes RNA primer to start new DNA synthesis -Elongation -DNA polymerase III (complex protein) binds to DNA template + RNA-primer + adds nucleotides complementary to template strand; proofreads DNA + removes errors -New DNA synthesis occurs in 5’ to 3’ direction on template running in 3’ to 5’ direction -due to nature of enzyme DNA polymerase- links new deoxy-nucleoside triphosphates (dNTPs) to 3’-OH group -H-bonding in base pairing works only if new strand runs in opposite direction of template DNA -DNA Polymerase I removes RNA primer + completes DNA strand -DNA ligase joins 2 ends of strands to complete DNA replication; DNA gyrase facilitates supercoiling to compact chromosomes -5. Leading strand:synthesized continuously from 5’ to 3’ based on the template -

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