Genetics Exam 2

Minimal Media

Nutrients required for growth of WT bacteria - varies per species (usually need C source, salts, and trace elements)

Phototrophs

Strains that don’t need nutritional supplementation

Auxotrophs

Strains unable to synthesize essential nutrients, need nutritional supplementation

Complete Media

Along with minimal media ingredients, includes vitamins, AA, etc

Screening for auxotrophs (5 steps)

Prototrophic Strain

Contact Dependent Gene Transfer Experiment

F Factor

Confers ability to form conjugation pilus 

Transfer of F Factor

Conjugation of Hfr cells with F- cells leads to _____

Using Hfr bacteria to map E. coli chromosome

Thr and leu transferred immediately (closer together in genome)

 

Using this you get relative distances of genes + order

Longer they were conjugated, more genes transferred

Conversion of Hfr bacterium to F’, mating with F- = F-duction

F’ Factors and F duction

Characteristics of E.coli cells w different types of F factors (F+, F-, Hfr, and F’)

Results of Conjugation between cells w diff F factors (F+ X F-, Hfr X F-, F’ X F-)

Transformation

Transfer of extracellular DNA into cells

Mapping by Transformation (4 steps)

Bacteriophages

Life cycle of virulent phage T2 (5)

Life Cycle of Temperate Phage lambda (Lytic V Lysogenic Cycles)

Discovery of Generalized Transduction

Gene Mapping by Transduction + Definition

Generalized Transduction

Co-Transduction of Genes - 2 ways it can occur

1) Close together on chromosome (1 infection)

2) Carried by 2 different phages (simultaneous infection)

Independent assortment: 2 genes on 2 different homologous chromosomes - recombination is ____

Linkage - 2 genes on single pair of homologs - no crossing over

Linkage - 2 genes on a single pair of homologs; exchange between non-sister chromatids

Chiasmata

Cis and Trans Doubly Heterozygous

The extent of linkage varies between diff _____

Gene Pairs

Linked Genes, Unlinked, and completely linked recombination rates

Genetic Maps

Crossing over frequency

Crossing over, no recombination

Chi Square and Linkage

Double Crossovers and Interference (coefficient of coincidence) 

Mapping human genes

Linkage analysis of human genes

GWAS

Hereditary Retinoblastoma

Griffith 1928 Exp

Avery 1944 Exp

Hershey- Chase Exp

Adenine

Guanine

Uracil

Cytosine

Thmine

DNA Double Helix discovered by

Watson and Crick, AND MAINLY Rosalind Franklin + Maurice Wilkins (x-ray diffraction)

X-ray diffraction of DNA

DNA has 2 distinctive regularities of ___ and ____ along the molecule

____ width for DNA restricted BP possibilities 

DNA polynucleotide chain

Nucleoside

N base + sugar (no phosphate)

H bonds between A and T and C and G

weak bonds

MP of bonds between G-C vs A-T

DNA gel electrophoresis general idea

A, B, and Z form DNA

Viral, Bacterial, Mitochondrial, and Chloroplast Chromosomes

Supercoiling + Topoisomerase 

Eukaryotic DNA Organization (Chromatin)

Nucleosome

Chromatin Remodeling

Modification of histone tails via acetylation, methylation, ubiquitination, and phosphorylation

Heterochromatin

Part of chromosome that remains condensed and is inactive (centromere, telomere), opposite of euchromatin 

Telomeres

Euchromatin V Heterochromatin (condensation, location, type of sequences, presence of genes, when replicated, transcription, and crossing over rate)

Conservative, Dispersive, and Semiconservative Replication

DNA rep in E. coli is _____

New nucleotides add to ___ end

4 basic requirements of DNA replication

DNA synthesis in bacteria requires ______ (_____ replication)

Bacterial Replication (4 steps)

Initiation Step 1 

Initiation Steps 2-5

Initiation Steps 6+7

Elongation (step 8)

Bacterial Rep is _____, ___ replication forks

Elongation step 9

Leading V Lagging Strands

DNA looping allows _____ to synthesize both strands at the rep fork

Termination of replication (bacteria)

DNA supercoiling

Rep in E. coli overview

DNA rep in eukaryotes

Replicon

from the origin of rep to the 2 termini of rep

There are ____ origin(s) of rep and rep bubbles in linear chromosomes

Linear chromosome problems (5’ end problem)

Synthesis of telomeric DNA by telomerase in tetrahymena

_____ synthesis is coordinated with DNA rep

histone

DNA rep includes packaging

PCR

PCR steps

Holiday model of recombination

Holiday steps 1-3

Holiday steps 3-5

Holiday steps 6-7

Holiday final step

Holiday model final products