Exam 4 Flashcards
base substitution that leads to a change in the amino acid sequence of the encoded polypeptide
missinse mutation
point mutation in which a purine is interchanges with a pyrimidine, or vice versa
transversion
mutation that does not alter the AA sequence of the encoded polypeptide even though the nucleotide sequence has changed
silent mutation
point mutation in which one base is substituted for another
base substitution
5-AACGCTAGATC-3 —> 5-AACGCTC-3
3-TTGCGATCAG-5 —> 3-TTGCGAG-5
deletion
mutation that involves a change from a sense codon to a stop codon
nonsense mutation
mutation that involves the addition of nucleotides not in a multiple of three and thereby alters the reading frame of the codon sequence downstream from the mutation
frameshift mutation
point mutation involving a change of a pyrimidine to another (e.g., C to T) or a purine to another urine (e.g., A to G)
transition
housekeeping genes require regulatory factors to function
false
embryonic transcription ca be controlled through covalent attachments
true
chromatin remodeling can cause heterochromatin to become euchromatin
true
CpG islands are the site of _____ , which may enhance or prevent binding of regulatory transcription factors through silencing
methylation
RNA that is non-coding may acts as a scaffold for protein complexes
true
antisense RNA is an example of non-coding RNA
true
mutations may be favorable by natural selection
true
a regulatory transcription facto may be modified through
protein-protein interactions
up-regualtion results n
increased gene expression
highly regulated genes are typically
tissue-specific
Germ-line mutations result in mosaic organisms
false
a conditional mutant can thrive in all conditions
false
repressors bind to
silencer sequences
a nonsense mutation is not likely to be a neutral mutation
true
lethal mutations are most commonly found in adults
false
why is chromatin remodeling necessary?
so transcription factors can gain access to target sequences
what is one way ATP-dependent chromatin-remodeling complexes can change chromatin structure?
evicting a histone
which type of mutation has the potential to have the greatest effect on more cells overall?
germ-line mutation
3 ways regulatory transcription factors can be modified
- small-effector molecule binding
- protein-protien interaction
- covalent modification
difference btwn a deleterious and lethal mutation.
deleterious mutation causes a detrimental effect to the phenotype.lethal mutation leads to the death of a cell
example of a mutagen for an induced mutation
UV, toxins, chemicals
