AP bio chapt 9 Flashcards
DNA and its role in heredity: Needed to show the three following…
DNA
Evidence: DNA in the Nucleus
Nuclein; Precipitation of DNA from White blood cell (WBC)
In 1868, Miescher:
Was extracting DNA from puss in wounds
Evidence: Doubles in the cell cycle
Flow Cytometry
Evidence: Twice as much in diploid cells
Further flow cytometry
Evidence: DNA is transmitted
NAME?
Bacteriophage:
Virus that attacks bacteria
Elucidating the structure of DNA: Why so key to know DNA structure? 2 important q’s:
- How is DNA replicated between cell division
Elucidating the structure of DNA: Crucial piece of evidence…
Crucial piece of evidence came from x-ray diffraction. Roseland Franklin
NAME?
Found: 2/28/1953
Double Helix: 4 key features:
- Double stranded.
Chargaff’s Rule
DNA from many species exhibited the certain regularities.
Structure Confers Function: 4
- Storage of genetic information
Structure confers function: 1. Storage of genetic information
We are looking at the nucleotide sequence: summarize by saying “Variations = differences”
Structure confers function: 2. Precise replication during cell division
complementary base pairing. This was huge as we now have a way of copying
Structure confers function: 3. Susceptibility to mutations
Change in sequence
Structure confers function: 4. Expression of coded information as phenotypes
DNA –> RNA –> Proteins
DNA replication is semiconservative:
They realized there must be a copying mechanism. Each parental strand is a template.
DNA replication is semiconservative: 2 general steps:
- DNA unwound
DNA replication is semiconservative: Ways to read the DNA.
The parent strand is read in a 3’ to 5’ manner. Nucleotides are added 5’ to 3’ direction.
Nucleotides added to new strand of DNA on 3’ end:
DYKNOW NOV 9 slide 5 look up and understand
Origin of Replication
- Many ORi’s: 10,000-40,000 bases
DNA Replication and Primase: A ___ ___ is needed
Starter Strand is needed: primer
DNA Replication and Primase: Most of time is:
RNA