1. Synthetic lethal- A screening method used to uncover mutations in a second gene that will require the cell to maintain a wild-type copy of the gene being studied in order to survive st mutation + 2nd mutation = lethality This screen is commonly used in yeast genetics, but can be used in other model organisms as well.

2. Dead yeast don’t talk

3. a a b a A A a b a b X B

4. a b a b B A A a b a b B X

5. Mutation
The process that produces a gene or a chromosome set that is differing than that of the wild type.
The gene or a chromosome set that results from such a process.

6. Gene product DNA Protein mRNA RNA Structural Enzyme Structural
Functional &
Regulatory RNAs

10. a+ --> a- mutation (forward mutation)
a > a+ reverse mutation (reversion)

11. Forward
Reverse

12. Presence of pink pigment + / -
Four-o’clock plants
Incomplete dominance the term used to describe the general case in which the phenotype of a heterozygote is intermediate between those of the two homozygotes, on some quantitative scale of measurement

13. Point mutations at the molecular level
Purine replaced by a different purine; pyrimidine replaced by a different pyrimidine: TRANSITIONS
Purine replaced by a pyrimidine; pyrimidine replaced by a purin:
TRANSVERSIONS

14. Transition and transversion

22. Now, insertions and deletions of base pairs:

24. Selection of auxotrophs by filter enrichment
Forward mutation-A mutation that converts
a wild-type allele into a mutant allele

25. Reverse mutation-The production of a wild-type gene from a mutant gene

27. Intragenic suppressor
Equivalent reversion
UCC (Ser) forward UGC (Cys) reverse AGC (Ser)
Wild type Mutant Wild type
CGC (Arg, basic) forward CCC (Proline) reverse CAC (His, basic)
Wild type Mutant Pseudo-wild type

28. Intragenic suppressor

29. Intergenic suppressor

30. Intergenic suppressor
Nonsense
suppressor

33. ADE2

34. ade2

35. The Sup11 case WT
ade2-101
ade2-101
sup11

36. The Sup11 case

37. Chromosome transmission fidelity (Ctf) assay
non-essential Chromosome Fragment M
SUP11
ade2-101 WT
ade2-101
kar3D
sic1D
rad50D
xrs2D
CIN mutant
ade1-101
ade2-101

38. Regulatory
Coding

42. A situation in which the third nucleotide
WOBBLE
A situation in which the third nucleotide
of an anticodon (at the 5’ end) can form two alignments.
This third nucleotide can form hydrogen bonds not only with its
normal complementary nucleotide in the third position but
also with different nucleotide in the position.

44. I stands for inosine, one of the rare bases found in tRNA, often in anticodon

46. The genetic code is said to be degenerate because in many cases
MESSAGE
The genetic code is said to be degenerate because in many cases
more then one codon is assigned to a single amino acid, and, in addition,
several codons can pair with more then on anticodon (wobble)