Linkage and Mapping
To determine the recombination frequency between 2 genes, you must perform this cross
AaBb X aabb
C to T
transition
A trisomy of chromosome 22 would be an example of this type of chromosomal abnormality
Aneuploidy
If a diploid individual has a recessive mutation on one chromosome and a deletion of the same region on the homologous chromosome, the recessive mutation will show this
pseudodominance
This type of repair is activated by chemically-altered bases
Base excision repair
You conduct a 3-point testcross between 3 linked genes to create a map. You get the following results: Which gene is in the middle?
5abC
200 ABC
52AbC
48aBC
211 abc
54aBc
4ABc
47 Abc
C
Huntington's disease, ALS, and Fragile X can all be caused by this type of mutation
repeat expansion
Crossing-over between 2 homologous chromosomes that are misaligned can cause these mutations
dels/dups
A spontaneous replication error can be caused by this movement of a H ion to another electronegative atom in the same base, creating new base pairing possibilities
tautomeric shift
uv radiation damage activates this type of repair pathway
Nucleotide excision repair
This is a measure of what proportion of expected double cross-over events are actually observed in a test cross
Interference
A base substitution that changes an amino acid to a stop codon in the resulting sequence
nonsense
Down syndrome can be cause by trisomy, or by this type of chromosomal rearrangement
translocation
A mutation in a second gene that restores a wildtype phenotype to an organism with a phenotypic mutation in another gene
intergenic suppressor
A C matched with an A in DNA would activate this repair pathway
Mismatch repair
3 genes are linked with a negative interference. What does this mean in practical terms
More double crossovers are observed than predicted by single crossover rates
A mutation that returns a mutated base back to wildtype sequence
reverse
While common in plants, this chromosomal abnormality can occur in certain cells of humans, including cardiac cells after damage
polyploidy
You cross a green fat (AaBb) fly with a orange skinny (aabb) fly. You get the following results: Were the genes in your Green fat fly in coupling or repulsion?
17 Green fat
210 Green skinny
187 orange fat
25 orange skinny
Repulsion
DNA Glycosylases are important for this type of DNA repair
Base excision
You want to determine whether 2 genes assort independently. You obtain the following data from a test cross:
Aa aa Total
Bb 100 10 110
bb 10 100 110
Tot 110 110 220
What are the expected number of aabb offspring from this cross?
110*110/220=55
Removal of an NH2 group from a base, creating a different base, for example, C to U
Deamination
These elements carry repeat sequences around the genome, and are a major driver of chromosome structure rearrangements
transposons
You cross an green, knobby AaBb cucumber with a yellow, smooth aabb cucumber. The 2 genes are linked, with a recombination frequency of 25%. How many green smooth cucumbers would you expect in 120 offspring?
120 X .25 /2 = 15
When a double stranded break occurs in DNA, the homologous chromosome can be used to guide sequence repair in this type of DNA repair
Homology Driven