Genetics
Unlinked genes ratio
1:1:1:1
You are following two X-linked genes in a two-factor cross using Drosophila. If the genes assort independently, an F1 dihybrid female should produce _blank_.
1:1:1:1
DNA polymerase moves
3 to 5 on template
Lagging strand direction
3-5
Purines
Adenine and Guanine
A mutation that changes wild type allele to new allele
Forward mutation
Mutations are heritable if they occur in
Germ line cells
an enzyme that unwinds the double helix.
Helicase
Formation of new genetic combinations by exchange of parts of homologs
Recombination
SCOs
Single Cross Over
Structure formed at spot where crossing over occurs between homologs
chiasma
Pyrimidines
cytosine, thymine, uracil
Recombination frequency for linked genes
less than 50%
Bacteria have how many origins of replication?
one
A chemical agent is being assayed for mutagenicity using the Ames test. This agent would be judged to be a mutagen if the number of bacterial colonies on the test plate is______.
significantly higher than that of the control plate
DNA polymerase needs how many dNTP
4
DNA polymerase adds nucleotides in the direction
5 to 3 of new strand
Leading strand direction
5' to 3'
recombination frequency for unlinked genes
50%
what phenotypic ratio should the offspring of a two-factor cross between two dihybrids show, assuming that the two genes control different traits?
9:3:3:1
Transversion mutation
A point mutation in which a pyrimidine is substitued for a purine, or vice versa.
Ames test
A procedure using bacteria to identify potential carcinogens
PolyQ base pair repeat
CAG
Protein that binds to origin of replication and calls helicase
Initiator protein
On crossover along a chromosome makes a second unlikely
Interference
an enzyme that forms phosphodiester bonds between DNA fragments.
Ligase
Linked genes
Parental > Recombinants
a short, preexisting DNA oligonucleotide or RNA molecule to which nucleotides can be added by DNA polymerase.
RNA primer
covalent linkage between adjacent thymine residues in DNA that can cause mutation.
Thymine dimers
Point mutation examples
Transversion, insertion, transition, deletion
Thymine dimers are caused by
UV radiation
Point mutations
gene mutations involving changes in one or a few nucleotides
DNA is negatively charged because of
the phosphate backbone of DNA is negatively charged
Complementation
the process in which heterozygosity for loss-of-function mutant recessive alleles for two different genes produces a normal phenotype.
transition substitution
when a purine is replaced with a purine or a pyrimidine is replaced with another pyrimidine