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IB BIOLOGY………………..STUDY GUIDE
DNA - THE GENETIC MATERIAL
TERMS TO KNOW:
Pathogenic — disease causing organism.
Lytic cycle - reproductive cycle of virus. Virus attaches to host cell, injects its hereditary
material into the host cell, host cell reproduces new virus particles and host cell bursts
releasing new virus particles.
Nucleotide - monomer of DNA and RNA. Composed of a five carbon sugar, a phosphate
and a nitrogen base.
Helix - twisted, spiral shaped molecule.
Histones — proteins that DNA wraps around.
Nucleosomes - clusters of eight histone — DNA units.
Chromatin — strings of nucleosome “beads” joined.
Chromosome - tightly coiled chromatin. Thick enough to be seen during cell division.
Heterochromatin - chromatin so tightly coiled that it can’t encode RNA.
Euchromatin - chromatin loosely coiled and capable of encoding RNA.
DISCUSS THE FOLLOWING:
Discuss the experiments and contributions made by the following to the discovery of DNA as the
molecule of heredity:
Hammerling:
Griffith:
Avery, MacLeod, McCarty:
Hershey, Chase:
Fraenkel - Conrat:
THE DISCOVERY OF DNA STRUCTURE:
Discuss the contributions made by the following to the discovery of the physical structure of
DNA:
Miescher -
Levine -
Chargaff -
Wilkins and Franklin -
Discuss the Watson and Crick model of DNA structure:
Discuss Watson and Crick’s “semi-conservative” model for DNA replication:
Discuss how Messelson and Stahl confirmed Watson and Crick’s explanation of how DNA
replicated:
DNA REPLICATION:
Discuss the “semi-discontinuous” model for DNA replication. Use specific terms and be
thorough:
THE EUKARYOTIC CHROMOSOME:
Discuss the structure of the chromosome. Include in your discussion the terms “histone”,
“nucleosome”, “chromatin” and “chromosome.”
Discuss how Beadle and Tatum developed their “one gene - one protein theory.” How
would you modify this theory:
How did Sanger prove that genes code for proteins: