AP Bio Chapter 16 Part 1 Flashcards
What was known involving traits, but not known
Traits were inherited
How the process happened
What happened by the middle of the 20th century
Genetics was well established as a field of study
The most significant contribution to understanding how life works is
The discovery of DNA
What did observations of chromosomes during cell divisions demonstrate
They act in a way consistent with molecules of heredity
What are chromosomes made of and what does it suggest
DNA and protein, heritability is controlled by one of these 2 molecules
What did biologists previously think was the molecule for inheritance
Protein
What did people not know about DNA
It’s structure and function
What did Frederick Griffith, a Scottish microbiologist, discover
Bacteria could give other bacteria heritable traits, even after they were dead
THATS WHERE HE LEFT IT
How do bacteria grow
In colonies
You can have all the same bacteria but different
Strains
Examples of strains
Smooth strains
Rough strains
Same bacteria
What did Frederick get when he injected living S cells (control) in a mouse
It died
What did Frederick get when he injected living r cells in a mouse
Heathy mouse
What did Frederick get when he injected heat killed S cells (control) in a mouse
Healthy
What did Frederick get when he injected a mixture of heat killed S cells and living R cells in mouse
Dead mouse
What did Griffith conclude ?
DNA was transformed (there was a TRANSFORMING FACTOR—some molecule got out of R cells and into S cells)
What did Avery McCarry and MacLeod do
Found Griffiths factor, only DNA (Nucleic acid) allowed for transformation
Refined Griffiths experiment
What did Avery mccarry and Macleod know the transforming factor to be
A macromolecules
What did Avery mccarry and Macleod do
Exposed r strain streptococcus to purified S strain protein and purified S strain DNA
What were the results of Avery mccarry and Macleods experiment
Only the bacteria exposed to the S strain DNA were transformed —> not enough evidence for the latter
What did Hershey and chase do
The blender experiment
Worked with bacteriophages at cold springs harbor
What did Hershey and chase wonder
How does phage DNA or phage protein get into a cell when a virus binds to it
What did Hershey and chase do
Labeled the protein and DNA with radioactivity, and only DNA got in, which allowed for reproduction of the virus
What do viruses have none of and have
Enzymes carbs lipids
Protein coat with genetic material concentrated at the core
What did Erwin chargraff do
Demonstrated two major rules of DNA composition
- All species have different amounts of adenine thymine cytosine and guanine in their DNA
- In every species, the amount of C=G, A=T
What did Chargraff’s rules help develop
DNA structure
Who were Watson and crick and Franklin and Wilkins
2 competing teams to determine the structure of DNA
What did Watson and crick use
X ray diffraction data developed by Rosalind Franklin to develop their double helix model of the Nobel prize
Who won the Nobel prize
Watson crick and wilkins (1962)
Photo 51
The crucial data used by Watson and Crick, taken by Rosalind Franklin
What are the nitrogenous bases held together by
Weak hydrogen bonds
What is the antiparallel structure of DNA
5’ to 3’
3’ to 5’
What is DNA’s genetic code
The order of the bases
Bases in one strand are _________________ bonded to each other resulting in
Covalently
Phosphodiester bonds
Bases on ________ strands are ____________ bonded to each other forming what
Opposite
Hydrogen
Base pairs
