Module 2:
Transcription,
Translation, DNA
and Genetic
Code (weeks 6 +
7)
Chromosomal theory of inheritance - answer The theory
stating that hereditary traits are carried on chromosomes
(phenotypes are controlled by genes on chromosomes)
True. Bacteria (prokaryotes) carry their genetic material
as a single circular chromosome, without it being enclosed
by a nuclear membrane - answer True or False. Bacteria do
not have nuclei.
Smooth (S) and rough (R)
- smooth is wildtype
,- rough is mutant - answer 2 forms/strains of
Streptococcus pneumonia (pneumonia disease)
Smooth (wildtype) - answer Which of the 2 strains of
Streptococcus pneumonia is virulent? (Causes disease
readily)
Frederick Griffith - answer Discovered transformation in
pneumonia-causing bacteria (streptococcus pneumoniae)
by injecting this into mice
The ability of a substance to change the genetic
characteristics of a cell - answer What is the process of
transformation?
Griffith injected streptococcus pneumoniae into mice in
different forms. He found that injecting the live S
(smooth) form resulted in death of the mice and the
bacteria surviving. If he injected live R (rough) form, the
mice lives, but no bacteria recovered/survived (the
immune system cleared it up). This was also the same
result if he injected heat-killed S. However, injecting a
MIXTURE of R and heat-killed S resulted in the mice dying
and both forms of bacteria surviving. This was very
unexpected because individually, these bacteria did not
survive, and although the S form that was injected was
heat-killed, live S forms were recovered! The fact that live
R and dead S could produce live S trains suggests the
process of transformation, where this mixture allowed the
genetic characteristics of a cell to be changed. - answer
Explain exactly how Griffith discovered transformation in
his mice experiments with streptococcus pneumoniae
, Oswald Avery (with MacLeod and McCarty) - answer
scientist who discovered what the transforming factor was
in bacteria (DNA)
We know from the Griffith Experiments that if live R is
combined with heat-killed S, live S will result from it.
Avery wanted to know what component was responsible
for this transformation, so he combined this mixture with
various components to see what component would destroy
the heat-killed S, which would be the component that
causes transformation. A combination with protease that
would destroy proteins still showed live S, so proteins
could not be the transforming principle. A combination
with ribonuclease that would destroy RNA still showed live
S, so RNA could not be the transforming principle.
However, a combination with deoxyribonuclease that
would destroy DNA showed no surviving S, so this
suggests that DNA causes transformation.
Since, without DNA, no live S survived, this indicates that
the only one that could cause transformation was DNA and
that genes were made up of DNA. - answer Explain exactly
how Oswald Avery, MacLeod, and McCarty discovered that
genes were made up of DNA
Hershey and Chase - answer concluded that the genetic
material of the bacteriophage was DNA, not protein.
T2 bacteriophage - answer Very small virus that infects
bacteria and contains about equal amounts of protein and
DNA (nothing else), used by Hershey and Chase to
determine if DNA or proteins were the genetic material by
Transcription,
Translation, DNA
and Genetic
Code (weeks 6 +
7)
Chromosomal theory of inheritance - answer The theory
stating that hereditary traits are carried on chromosomes
(phenotypes are controlled by genes on chromosomes)
True. Bacteria (prokaryotes) carry their genetic material
as a single circular chromosome, without it being enclosed
by a nuclear membrane - answer True or False. Bacteria do
not have nuclei.
Smooth (S) and rough (R)
- smooth is wildtype
,- rough is mutant - answer 2 forms/strains of
Streptococcus pneumonia (pneumonia disease)
Smooth (wildtype) - answer Which of the 2 strains of
Streptococcus pneumonia is virulent? (Causes disease
readily)
Frederick Griffith - answer Discovered transformation in
pneumonia-causing bacteria (streptococcus pneumoniae)
by injecting this into mice
The ability of a substance to change the genetic
characteristics of a cell - answer What is the process of
transformation?
Griffith injected streptococcus pneumoniae into mice in
different forms. He found that injecting the live S
(smooth) form resulted in death of the mice and the
bacteria surviving. If he injected live R (rough) form, the
mice lives, but no bacteria recovered/survived (the
immune system cleared it up). This was also the same
result if he injected heat-killed S. However, injecting a
MIXTURE of R and heat-killed S resulted in the mice dying
and both forms of bacteria surviving. This was very
unexpected because individually, these bacteria did not
survive, and although the S form that was injected was
heat-killed, live S forms were recovered! The fact that live
R and dead S could produce live S trains suggests the
process of transformation, where this mixture allowed the
genetic characteristics of a cell to be changed. - answer
Explain exactly how Griffith discovered transformation in
his mice experiments with streptococcus pneumoniae
, Oswald Avery (with MacLeod and McCarty) - answer
scientist who discovered what the transforming factor was
in bacteria (DNA)
We know from the Griffith Experiments that if live R is
combined with heat-killed S, live S will result from it.
Avery wanted to know what component was responsible
for this transformation, so he combined this mixture with
various components to see what component would destroy
the heat-killed S, which would be the component that
causes transformation. A combination with protease that
would destroy proteins still showed live S, so proteins
could not be the transforming principle. A combination
with ribonuclease that would destroy RNA still showed live
S, so RNA could not be the transforming principle.
However, a combination with deoxyribonuclease that
would destroy DNA showed no surviving S, so this
suggests that DNA causes transformation.
Since, without DNA, no live S survived, this indicates that
the only one that could cause transformation was DNA and
that genes were made up of DNA. - answer Explain exactly
how Oswald Avery, MacLeod, and McCarty discovered that
genes were made up of DNA
Hershey and Chase - answer concluded that the genetic
material of the bacteriophage was DNA, not protein.
T2 bacteriophage - answer Very small virus that infects
bacteria and contains about equal amounts of protein and
DNA (nothing else), used by Hershey and Chase to
determine if DNA or proteins were the genetic material by
