sufficiently to be outside the range of immunity are soon spread in highly populated
areas.
14) present experimental evidence related to griffith’s experiment and the identification
of the cell’s genetic material.
when experimenting with streptococcus pneumoniae in the 1920’s, griffith noticed that
some colonies were shiny and smooth and some were rough in appearance. he called
the shiny colonies, the s strain’ and the rough colonies, the r’ strain. when griffith
injected mice with the s strain, which he discovered were encapsulated, they died. when
he injected them with the r strain, they did not die. in trying to determine what factor
was responsible for the s strain’s virulence, griffith heat-killed the s bacteria to destroy
the capsule. when he injected mice with the normally fatal s strain bacteria that had
been heat-killed, they did not die. however, if the heat-killed s strain bacteria were
mixed with harmless live r strain bacteria of the same species and injected, the mice did
die. surprisingly, living s strain bacteria were recovered from the bodies of the mice.
griffith concluded that some substance from the dead s strain bacteria passed to the r
strain bacteria, imparting virulence and the ability to form a capsule. avery and others
continued the search for the substance that “transformed” the r strain into the s strain.
hypothesis i: genetic material or “transforming substance” is protein.
hypothesis ii: genetic material or “transforming substance” is rna.
hypothesis iii: genetic material or “transforming substance” is dna.
an experiment was performed that demonstrated that the addition of protein-degrading
enzyme did not prevent transformation. this finding:
a. supports hypothesis i
b. supports hypothesis ii
c. supports hypothesis iii
d. rejects hypothesis i only.
e. rejects hypothesis ii only.
f. rejects hypothesis iii only.g. does not support any of these hypotheses.
15) where on this phylogenetic tree of primate evolution do you find the evolution of
humans and species very closely related to humans?