BIO 111 EXAM 3 QUESTIONS AND ANSWERS ELABORATIONS
BASED ON FINAL EXAM!!
Freiedrich Miescher
Answers:1869- Isolated phosphate rich acidic comp termed nuclein (DNA)- pus in
hospital bandages
Phoebus Leven
Answers:1920s- Isolated sugars of RNA and DNA and 4 diff nucleotides in DNA-
EST TETRANUCLEOTIDE HYPOTHESIS- equal ratios though
Frederick Griffith
Answers:1928- studies strep in in vivo model (mice)-- living R bacteria was
transformed into pathogenic S bacteria by some heritable substance
Avery, MacLeod, McCarty
Answers:1944- used in vitro (lab) model- strep- determined DNA is what was
transmitted from one gen to next
Erwin Chargaff
Answers:1950- analyzed base comp of DNA in multiple org.-- DNA comp varies
from species to species. % A = %T and %G = %C
Alfred Hershey and Martha Chase
Answers:1952- studies bacteriophages (T2)-- DNA accepted as THE inheritable
substance
Rosalind Franklin and Maurice Wilkins
, Answers:1952- Imaged DNA-- 2 antiparallel sugar phosphate backbones--
nitrogenous bases paired in molecules interior (image 51)
James Watson and Francis Crick
Answers:1953- developed double helix model-- T pairs w A, G pairs w C
Nucleotide
Answers:phosphate group, sugar, nitrogenous base
Pyrimidine bases
Answers:CUT- cytosine, thymine, uracil
Purine bases
Answers:AGs are pure-- adenosine and guamine
DNA double strand
Answers:- sugar and phosphate on outside, nucleotides on inside. Antiparallel and
directional
3' end vs 5' end
Answers:3'-- OH (hydroxyl) at end
5' end-- OPO3(phosphate group)- at end
euchromatin
Answers:DNA that gets expressed-- loosely packed chromatin
heterochromatin
BASED ON FINAL EXAM!!
Freiedrich Miescher
Answers:1869- Isolated phosphate rich acidic comp termed nuclein (DNA)- pus in
hospital bandages
Phoebus Leven
Answers:1920s- Isolated sugars of RNA and DNA and 4 diff nucleotides in DNA-
EST TETRANUCLEOTIDE HYPOTHESIS- equal ratios though
Frederick Griffith
Answers:1928- studies strep in in vivo model (mice)-- living R bacteria was
transformed into pathogenic S bacteria by some heritable substance
Avery, MacLeod, McCarty
Answers:1944- used in vitro (lab) model- strep- determined DNA is what was
transmitted from one gen to next
Erwin Chargaff
Answers:1950- analyzed base comp of DNA in multiple org.-- DNA comp varies
from species to species. % A = %T and %G = %C
Alfred Hershey and Martha Chase
Answers:1952- studies bacteriophages (T2)-- DNA accepted as THE inheritable
substance
Rosalind Franklin and Maurice Wilkins
, Answers:1952- Imaged DNA-- 2 antiparallel sugar phosphate backbones--
nitrogenous bases paired in molecules interior (image 51)
James Watson and Francis Crick
Answers:1953- developed double helix model-- T pairs w A, G pairs w C
Nucleotide
Answers:phosphate group, sugar, nitrogenous base
Pyrimidine bases
Answers:CUT- cytosine, thymine, uracil
Purine bases
Answers:AGs are pure-- adenosine and guamine
DNA double strand
Answers:- sugar and phosphate on outside, nucleotides on inside. Antiparallel and
directional
3' end vs 5' end
Answers:3'-- OH (hydroxyl) at end
5' end-- OPO3(phosphate group)- at end
euchromatin
Answers:DNA that gets expressed-- loosely packed chromatin
heterochromatin