Study Guide Questions with Actual
Answers.
Escherichia coli - Answer may acquire genes encoding virulence factors, converting them into
pathogenic strains, like this uropathogenic E. coli.
Freidrich Miescher - Answer The first person to isolate phosphorus rich material, from white
blood cells in pus from bandages, which he named "nuclein". What he had isolated was RNA
and DNA.
Richard Altmann - Answer Building on Miescher's work, noted the acid nature of nuclein and
renamed it nucleic acid.
Albrecht Kossel - Answer >>Further isolated and characterized nucleic acid by identifying five
different nucleotide bases. Adenine, guanine, cytosine, thymine (DNA),uracil(RNA).
>>Composed of nitrogenous base (A,G,C,T or U), a phosphate group, and a sugar deoxyribose
(DNA) or ribose (RNA)
Johann Gregor Mendel - Answer >>"Father of Genetics" -Used pea plants to demonstrate that
there was some heritable component -genes. See slides and outline.
>>continuous variation
>>dicountinuous variation
>>model system
>>Using self-fertilizing pea plants, which he then hybridized (cross-bred), he showed that
offspring showed predictable patterns.
>>Pgeneration-Cross-bred violet (PP) and white flowers (pp).uF1filialgeneration-All offspring
were violet (Pp) PpuF2 generation -3:1 ratio of violet to white (PP, Pp, pp)
Mendel's Pea Plants - Answer pruple folwer + white flower= P generation
the offspring of p generation, being purple as pruple is the dominant gene= F1 Generation
the offspring of F1 are one purple, one white= f2 generation
>>In one of his experiments on inheritance patterns, Mendel crossed plants that were true-
breeding for violet flower color with plants true-breeding for white flower color (the P
generation). The resulting hybrids in the F1generation all had violet flowers. In the
F2generation, approximately three-quarters of the plants had violet flowers, and one-quarter
had white flowers
, Walter Sutton and Theodor Boveri - Answer Chromosomal Theory of Independence
>>During meiosis, homologous chromosome pairs migrate as discrete structures that are
independent of other chromosome pairs.
>>The sorting of chromosomes from each homologous pair into pre-gametes appears to be
random.
>>Each parent synthesizes gametes that contain only half of their chromosomal complement.
>>Even though male and female gametes differ in size and morphology, they have the same
number of chromosomes, suggesting equal genetic contributions from each parent.uThe
gametic chromosomes combine during fertilization to produce offspring with the same
chromosome number as their parents.
Chromosomes - Answer genetic material responsible for inheritance
Thomas Hunt Morgan - Answer Using the Drosophila melanogaster fruit fly, made microscopic
observations of fly chromosomes and correlated them with fly characteristics.
Barbara McClintock - Answer Developed chromosomal staining techniques to visualize and
differentiate between different chromosomes of maize/corn. Observed transposons-a DNA
sequence that can relocate in the genome, however, was not given credit for this discovery for
some time.
Joachim Hammerling - Answer Using the single-celled alga Acetabularia, demonstrated that
the genetic information in a eukaryotic cell is found within the nucleus. See slides and outline
George Beadleand Edward Tatum - Answer Using Neurospora crassa, red bread mold, led to
the one-gene-one-enzyme hypothesis, showing the link between genes and corresponding
characteristics -in this case the gene coding for amino acid synthesis. See slides and outline
Frederick Griffith - Answer Demonstrated horizontal transfer of genetic information between
bacteria by using Streptococcus pneumoniae (rough and smooth) and mice. See slides and
outline
Oswald Avery, Colin MacLeod, and Maclyn McCarty - Answer Building on Griffith's work they
were able to isolate the S strain S. pneumoniae, from the dead mice and demonstrate that it
was DNA which conferred the virulence. See slides and outline.
Martha Chase and Alfred Hershey - Answer Using radio-tagged sulfur and phosphorus were
able to demonstrate that it was phage DNA that was injected into bacteria and which carried
genetic information and not the protein of the capsid. See slides and outline.