Genetics

• DNA strands are separated during replication.
• DNA contains Phosphorus but not sulfur, Protein contains sulfur but notphosphorus.
• DNA labeled by 32P and protein labeled by 35S.
• The radioisotopes in the bacteria were traced after separation from the phage,most of the P-labeled DNA was now inside the bacterial cell, nearly all theS-labeled protein was outside of the cell as ‘ghost’ phage coats.
• Single stranded DNA or RNA probes are added to mitotic cells and monitored for hybridization.
• Fluorescent or radioactive labels are used for detection to determine chromosomal locations of specific genetic information.
• Molecules separate under the influence of an electric field through a semisolid agarose gel and a buffer solution.
• DNA in the chromosome is a target for hybridization.
• Fluorescent dyes are used to visualize different bands.
• Electrophoresis separates DNA and RNA fragments based on size and charge.
• The gel can have different pore sizes based on what you are trying to separate.
• Small molecules and more negative molecules will travel further down the gel toward the positive anode.
• Electrophoresis is used in blotting techniques.
• Progeny phages from lysed DNA only contained P32.
• Helped determine proteins weren’t involved in reproduction but DNA was directlyinvolved.
• Transfection- showed if lysozyme was used, the outer wall of a cell could be removedwithout harming the bacterium (forming protoplasts).
• Protoplasts were used to initiate phage reproduction w/ T2 phages- showedviruses didn’t need an intact protein coat for infection.
• Transfection- infection by only the viral nucleic acid.
• DNA was purified from a bacteriophage containing single strandedcircular DNA, produced complete bacteriophages when added to bacteria.
• Showed DNA alone was all that was necessary for production ofviruses.
• Eukaryotic organisms hadn’t been used to demonstrate DNA as genetic material in the1950’s, but it was assumed it would be universal throughout prokaryotes and eukaryotes.
• Indirect evidence- DNA Distribution.
• Both DNA and proteins were found in the nucleus, but proteins are also foundthroughout the cell.
• DNA is found in the chromosome, mitochondria, and chloroplast- all performgenetic functions.
• DNA existing in the chromosome implies a link between the ploidy of a cell andthe quantity of genetic material.
• Comparison the amount of DNA between diploid somatic cells andhaploid gametes.
• Indirect evidence- Mutagenesis.
• UV light induces mutations in genetic material, with different wavelengths of UVlight producing different levels of mutations.
• Effectiveness creates an action spectrum of UV light and mutations.
• DNA and RNA absorb UV light most strongly at 260 nm, which is UV light’s mostmutagenic wavelength.
• Proteins absorb most strongly at 280 nm, where no significant mutagenic effectsare shown.
• Shows nucleic acids are likely the genetic material due to its ability to be mutated.
• Recombinant DNA technology splices DNA sequences from different organisms.
• When recombinant DNA is introduced to bacteria, it is replicated andpassed down through cell division where it is expressed.
• Shows how specific DNA sequences contain heritable information to produce acertain gene.
• Nitrogenous bases of the chains are paired to form hydrogen bonds between A-T and C-G pairs.
• Each carbon in a nucleotide is numbered with a prime sign.
• Each complete turn of the helix is 34A long, so each turn is 10 base pairs.
• Purines are covalently bonded to the sugar at the N-9 position, while pyrimidines are at the N-1 position.
• Ribose and deoxyribose are separated by an oxygen.