SBI4U Molecular Genetics Review
Explain the significance of this experiment
SBI4U Molecular Genetics Review
Griffith Experiment proved bacterial transformation occurred
through a physical, heritable means: but, was it protein or DNA?
Still not conclusive…
SBI4U Molecular Genetics Review
Explain the
significance of
this experiment
SBI4U Molecular Genetics Review
Hershey &
Chase
Experiment
35S
32P
Demonstrates
that it’s DNA,
not protein,
passed on from
one generation
to another:
35S
not found in
offspring virus
32P
present in
offspring virus
SBI4U Molecular Genetics Review
Another Look at the
Hershey & Chase
Experiment
SBI4U Molecular Genetics Review
U. DNA Nucleotide
W
V. Phosphate
Z
V
W.Adenine
U
Y
X.Cytosine
Y. Gene Locus, DNA
backbone
X
Z. Hydrogen bonds
SBI4U Molecular Genetics Review
Avery & MacLeod Experiment: If you damage
DNA, you destroy heredity.
SBI4U Molecular Genetics Review
Match-up Question:
1. Meselson & Stahl = C
2. Chargaff = G
3. Meischer = E
4. Franklin = A
5. Watson & Crick = H
6. Hershey & Chase = F
7. Avery, MacLeod, McCarty = D
8. Griffith = B
SBI4U Molecular Genetics Review
Identify the labeled structures:
A Amino Acid
B tRNA
C Anticodon
E mRNA
F Ribosome
G Polypeptide
SBI4U Molecular Genetics Review
Identify the labeled structures:
1 Lagging Strand
2 Leading Strand
3 DNA pol.
4 Ligase
5 RNA Primer
6 Primase
7 Okazaki fragment
8 DNA pol.
9 Helicase
10 ssb’s
11 Gyrase
SBI4U Molecular Genetics Review
Review Booklet – 6.4 DNA Replication & Repair
Q 1: Replication is more suitable because it conveys not
only the precision required, but also the semi-conservative
nature of DNA synthesis: “half old, half new”
Q 3: Table 1 information:
R.O: the starting point, at an RNA primer
H: Unzips DNA strands
R.F: point of DNA strand separation
T: aka gyrase; untwists DNA helix
SSB: loosely bound to DNA strands, prevent reannealing
R.B.: gap between two replication forks
SBI4U Molecular Genetics Review
Review Booklet – 6.4 continued
Q 4: Table information:
NT: provides bases for the nucleotides
PB: strong covalent bond of DNA backbone
RNAp: builds a primer needed for DNApol
RNA primer: provides attachment pt for DNApol
DNApolIII: extends the DNA chain
LdS: 5’  3’ direction, continuous synthesis
LgS: 3’  5’ orientation, discontinuous syn.
OF: short DNA strands of Lagging strand
DNApolI: aka RNAse H; removes primer
Ligase: joins Okazaki fragments
SBI4U Molecular Genetics Review
Review Booklet – 6.4 continued
Q 5: Table information:
Bp mismatch leads to a bulge or twist in the DNA double helix.
The weakened point could lead to a gross chromosomal
mutation.
DNA repair complex, involves DNApol II & I; able to ‘edit’ point
mutations in most cases by excising incorrect nucleotide,
replacing w correct one.
Q 6: Diagram Labels:
1. Helicase & Gyrase
2. Replication Fork
3. SSb’s
4. Ligase 5. point of ligation
6. DNA Polymerase III 7. Template strand
8. 9. Okazaki fragments 10. RNA primer 11. Primase
SBI4U Molecular Genetics Review
Review Booklet – 7.2 Transcription & 7.3 Translation
Q 1: Table information:
Promoter + TATA Box: site of RNA polymerase binding
RNA Polymerase: synthesis of new mRNA strand
Coding strand: DNA strand NOT being transcribed. 5’ 3’
Template strand: 3’  5’ strand of DNA that IS being
transcribed.
*it must be this strand in order to ensure mRNA is made in
5’  3’ direction
Start Codon: TAC triplet that indicates start point of
transcription
Q 2: uh….. Transcription, perhaps? Give us some credit,
textbook.
Q 1: tRNA is much shorter than mRNA
Q 2: why yes, I do have a picture to show you!
SBI4U Molecular Genetics Review
Review Booklet –7.3 Translation
Q 3: Anticodon sequences will be: CAA, CGG, UUU, GGA
Q 4: This is a property of the code called Code Redundancy. A limited
set of bases in the ribonucleotides (A, C, G, U) can be rearranged into 61
codons (64, with the stop codons!) for the 20 amino acids. Proteins are
built out of a limited ‘alphabet’ of 20 amino acids by repetition and
duplication of them, as needed.
Q 5: A Ribosome is made of two different parts, called the small
and large ribosomal subunits. mRNA threads through a ribosome.
A tRNA molecule, with an amino acid attached to it and the
anticodon that pairs with the amino acid’s mRNA codon,
introduces the amino acid to be added to the polypeptide chain
next. The amino acid is added to the chain and the tRNA is
released. Other tRNA molecules add subsequent amino acids to
the polypeptide.
And that, children, is the world’s lamest fill in the blanks paragraph. #aminoacid
SBI4U Molecular Genetics Review
Review Booklet – Chapter 7 summary
Q 5: Transcription diagram:
a. DNA b. RNA polymerase c. mRNA
Q 6: Translation diagram:
a. Ribosome b. mRNA
c. anticodons d. codon
e. Ribosomal large subunit, A site
f. P Site g. E site h. polypeptide
i. tRNA
SBI4U Molecular Genetics Review
Review Booklet – short answer questions
Q 1: DNA excision (cutting) by restriction enzymes, and
complementary pairing
Q 2: Bacteria conjugate, Viruses transfer plasmids to
host cells
Q 5: Introduction of desirable traits into crop
plants or farm animals
Q 6: By creating transgenic bacteria to produce
clotting factor much more quickly in a lab setting
Q 7: Paternity testing; criminal forensics; paleobiology;
taxonomy; identification of missing persons, etc.
SBI4U Molecular Genetics Review
Review Booklet – short answer questions
Q 9 - 20: Matching Test
9B 10C 11E 12A 13B 14D
15C 16B 17E 18B 19C 20B
Q 21: A Q 22: E Q 23: B
Q 24: E
Q 25: B Q 26: B Q 27: E
SBI4U Molecular Genetics Review
Review Booklet – short answer questions
Q 4-13: 4A 5B 6A 7B 8A 9B 10B 11B 12A 13B
Q14-21: 14B 15B* (really all of them!)
16A 17B 18C 19A 20B 21B
Q22: ACGGAAUCUUC
Q23. Initiation: Binding of mRNA to Ribosome,
translation begins; Elongation: adding a.a. to
the polypeptide; Termination: release of
ribosome when STOP codon reached.
SBI4U Molecular Genetics Review
Review Booklet – short answer questions
Q 25-29: 25C 26A 27A 28B,D 29D
Q30: Absence of Lactose: Repressor protein is free to
bind to DNA & prevent transcription. Presence of Lactose:
Repressor protein is disabled by Lactose, changed shape
prevents it from binding to DNA – transcription proceeds
as RNA polymerase binds to DNA.
Q31. Exons = coding; Introns = junk DNA.
Q32. Promoter = identifies beginning of gene locus, binds
RNA polymerase; Enhancer = binds proteins that enhance
(improve, promote) transcription.
Q 34: A
Q 35: A
SBI4U Molecular Genetics Review
Review Booklet – short answer questions
Q 6,7,8: See notes on DNA discovery!
Q 9: TCCAGTTACGCG
Q 10: Semi-conservative: half old, half new; template
DNA opens up & is copied by enzymes, producing two
new DNA molecules, each consisting of one template
strand & one new.
Q12-16: 12D 13B 14C 15A 16E
Q17. C
Q19: C
Q 18: B or D both valid
Q 20: E
Q 21: D