Topic 2-1 Flashcards
genetic material must be able to:
- contain large amounts of complex information
- replicate faithfully
- encode the phenotype
- have the capacity to vary
Johann Friedrich Miescher performed the first chemical analysis of the substance present in nuclei and found:
a substance that is slightly acidic and high in phosphorus
who discovered nuclein?
Miescher
what cells did Miescher isolate nuclei from?
white blood cells in pus from bandages from a nearby clinic
what did Miescher think about the role of nuclein in heredity?
he believed that proteins were the substance that carried hereditary information
Albretch Kossel and Phoebus Levene investigated the chemical nature of:
nucleic acids
Kossel determined that there were four nitrogenous bases:
adenine, thymine, guanine, and cytosine
Levene discovered that DNA is a:
polymer
Levene proposed that DNA consisted of a series of repeating, invariant, 4-nucleotide units in a fixed sequence. this is known as the:
tetranucleotide hypothesis
what is Chargaff’s rule?
adenine is always equal to thymine, and guanine is always equal to cytosine
does chargaff’s rule support or disprove the tetranucleotide hypothesis?
disproves it
which three experiments supported the hypothesis that hereditary information is encoded in nucleic acids?
- Griffith’s experiment
- Drs. Avery, Macleod, and McCarty’s experiment
- the Hershey-Chase experiment
Fred Griffith’s experiment demonstrated:
transformation in bacteria
Avery, McCarty, and Macleod’s experiments revealed:
that the transforming principle is DNA
what is T2?
a bacteriophage that infects E. coli
