Lecture 1

Question 1

nucelic acids and inheritance

Answer 1

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Question 2

bacterial transformation experiment

Answer 2

• frederick griffith worked with 2 strains of steptococcus pneumoniae (pathogenic S strain; harmless R strain)
• S cell = dead mouse
• R cell = healthy
• heated S = healthy
• heated S + normal R = dead

Question 3

transformation

Answer 3

• change in genotype due to assimilation of foreing DNA

Question 4

radioactive tracing experiment

Answer 4

• alfred hershey, martha chase
• protein / DNA component of T2 phages that infect bacterial cells and reprogram them
• used radioactive sulphur and phosphorous to trace fates of protein/DNA during E.coli infection

Question 5

E.coli structure

Answer 5

• phage head: coat (protein) ; DNA (or RNA)
• tail sheath (protein)
• tail fibre (protein)

Question 6

Batches

Answer 6

• 1: grown in sulphur; blended; centrifuged;
• 2: grown in phosphorous; blended; centrifuged;
• evidence that DNA injected by phage allows bacterial cell to produce new viral DNA and proteins

Question 7

nucelotide

Answer 7

• monomer (building block of DNA)
• nitrogenous base; pentose sugar; phosphate group
• 4 dfferent types (ATGC)
• equal amount of ATCG in species

Question 8

DNA structure

Answer 8

• x-ray crystallography
• two antiparallel sugar-phosphate backbones with nitrogenous bases paired in molecules interious
• helical molecule

Question 9

DNA base pairing

Answer 9

• purine with pyramidine
• Adenine + Thymine
• Guanine + Cytosine
• AG = purine
• TC = pyramidine