DNA Properties Test Notes 2017-04-02
Hassan Alibhai Page DP1
Important People
Name Contribution Image if Needed
Gregor Mendel • Austrian scientist-friar
• “The Father of Modern Genetics”
• Researched patterns of inheritance by experimenting with garden peas,
and their colour, size, stem length, etc.
• Discovered alleles, and dominant and recessive traits: “Mendel’s Laws
of Inheritance”
Friedrich Miescher • Swiss biochemist and physician
• Isolated a non-protein substance from the nuclei of white blood cells
obtained from pus found in bandages from wounds
◦ Called in nuclein, (now called nucleic acid)
• Showed that proteins are not hereditary material (first person)
Phoebus Levene • Russian-american biochemist
• Isolated DNA and RNA based on sugars: deoxyribose and ribose
◦ Made of nucleotides → sugar + phosphate + nitrogen base
◦ Thought that nucleotides repeated (AGCTAGCT....), too simple to
be genetic material → incorrect but people believed him
Frederick Griffith • British microbiologist
• Tried to develop a vaccine against
pneumonia
• heat + virulent pneumococcus + non-virulent
pneumococcus → death
• Discovered transformation, where bacteria
pick up DNA from the environment
Joachim Hammerling • Danish-German biologist
• Experiment on green algae showed that algae
had to have a “foot” to regenerate
◦ Foot had nucleus, so nucleus has DNA
Oswald Avery • Canadian born (Halifax) American medical researcher (with McCarty
and MacLeod)
• Transforming Principle (with Griffith’s work) → it was DNA
• Further evidence that DNA is hereditary
Alfred Hershey and • American geneticists
Martha Chase • Radioactively labelled viruses infected bacteria cells → tagged DNA
with phosphorous, and proteins with sulphur
◦ Only phosphorous transferred → DNA is hereditary
◦ Confirmed for the last time, now scientific community accepts it
, DNA Properties Test Notes 2017-04-02
Hassan Alibhai Page DP2
Heinz Fraenkel-Conrat • German biochemist
• Experimented with viruses to determine if
protein or RNA is responsible for replication
• Isolated TMV and HRV, each contained
protein and a single strand of RNA
• Created a hybrid with the RNA from HRV
and protein from TMV
• Tobacco plant had lesions on leaves, property
of HRV virus, meaning that RNA is
responsible for virus replication and is in the
nuclear core of viruses.
Erwin Chargaff • Ukrainian born American biochemist
• Worked on a variety of organisms and
analyzed the various DNA compositions
• Determined that
◦ DNA compositions are species specific
(all are different)
◦ Adenine pairs with Thymine (A = T)
◦ Cytosine pairs with Guanine (C = G)
◦ A + G = T + C (Chargaff’s Rule)
Franklin and Wilkins • Tension between them, they were studying
DNA using x-rays at the same time
• DNA is long and thin
• DNA has a uniform, 2nm diameter
• DNA coils (turns completely) every 3.4nm.
• DNA has some kind of helical shape
Watson and Crick • Used the work of Chargaff, Franklin, and
Wilkins to determine that DNA has a double
helix shape
◦ Held together by hydrogen bonds
between AT and CG (2 + 3 respectively)
• DNA varies by species
• Awarded 1962 Nobel Prize with Wilkins
◦ Franklin died before she was awarded
• Side Note: PCR was invented by Kary Mullis, which is in the exam review despite not yet being
covered.
Hassan Alibhai Page DP1
Important People
Name Contribution Image if Needed
Gregor Mendel • Austrian scientist-friar
• “The Father of Modern Genetics”
• Researched patterns of inheritance by experimenting with garden peas,
and their colour, size, stem length, etc.
• Discovered alleles, and dominant and recessive traits: “Mendel’s Laws
of Inheritance”
Friedrich Miescher • Swiss biochemist and physician
• Isolated a non-protein substance from the nuclei of white blood cells
obtained from pus found in bandages from wounds
◦ Called in nuclein, (now called nucleic acid)
• Showed that proteins are not hereditary material (first person)
Phoebus Levene • Russian-american biochemist
• Isolated DNA and RNA based on sugars: deoxyribose and ribose
◦ Made of nucleotides → sugar + phosphate + nitrogen base
◦ Thought that nucleotides repeated (AGCTAGCT....), too simple to
be genetic material → incorrect but people believed him
Frederick Griffith • British microbiologist
• Tried to develop a vaccine against
pneumonia
• heat + virulent pneumococcus + non-virulent
pneumococcus → death
• Discovered transformation, where bacteria
pick up DNA from the environment
Joachim Hammerling • Danish-German biologist
• Experiment on green algae showed that algae
had to have a “foot” to regenerate
◦ Foot had nucleus, so nucleus has DNA
Oswald Avery • Canadian born (Halifax) American medical researcher (with McCarty
and MacLeod)
• Transforming Principle (with Griffith’s work) → it was DNA
• Further evidence that DNA is hereditary
Alfred Hershey and • American geneticists
Martha Chase • Radioactively labelled viruses infected bacteria cells → tagged DNA
with phosphorous, and proteins with sulphur
◦ Only phosphorous transferred → DNA is hereditary
◦ Confirmed for the last time, now scientific community accepts it
, DNA Properties Test Notes 2017-04-02
Hassan Alibhai Page DP2
Heinz Fraenkel-Conrat • German biochemist
• Experimented with viruses to determine if
protein or RNA is responsible for replication
• Isolated TMV and HRV, each contained
protein and a single strand of RNA
• Created a hybrid with the RNA from HRV
and protein from TMV
• Tobacco plant had lesions on leaves, property
of HRV virus, meaning that RNA is
responsible for virus replication and is in the
nuclear core of viruses.
Erwin Chargaff • Ukrainian born American biochemist
• Worked on a variety of organisms and
analyzed the various DNA compositions
• Determined that
◦ DNA compositions are species specific
(all are different)
◦ Adenine pairs with Thymine (A = T)
◦ Cytosine pairs with Guanine (C = G)
◦ A + G = T + C (Chargaff’s Rule)
Franklin and Wilkins • Tension between them, they were studying
DNA using x-rays at the same time
• DNA is long and thin
• DNA has a uniform, 2nm diameter
• DNA coils (turns completely) every 3.4nm.
• DNA has some kind of helical shape
Watson and Crick • Used the work of Chargaff, Franklin, and
Wilkins to determine that DNA has a double
helix shape
◦ Held together by hydrogen bonds
between AT and CG (2 + 3 respectively)
• DNA varies by species
• Awarded 1962 Nobel Prize with Wilkins
◦ Franklin died before she was awarded
• Side Note: PCR was invented by Kary Mullis, which is in the exam review despite not yet being
covered.
