(Pierce, 2020), Chapter 1-26 | 9781319216801 All Chapters
with Answers and Rationals .
mutations are the - ANSWER: primary source of genetic variation, the raw material for evolution
two basic classes of mutations - ANSWER: somatic and germ line
somatic mutations - ANSWER: occur in nonreproductive cells and are passed to new cells through
mitosis, creating a clone of cells with mutant gene
germ line mutations - ANSWER: occur in cells that give rise to gametes, meiosis and sexual
reproduction allow mutations to be passed to half the members of the next generation who will carry
the mutations in all their cells
how often is somatic mutations + other info - ANSWER: 1 in one million,
some cause disease like cancer,
mosaicism can result
classes of mutation - ANSWER: base pair changes,
base pair insertion or deletion,
expansion of nucleotide repeats,
gene copy number expansion
three types of DNA sequence mutations - ANSWER: substitutions, insertions, and deletions
substitution mutation - ANSWER: base substitution alters a single codon
insertion mutation vs deletion - ANSWER: insertion or deletion alters the reading frame and may
change many codons
substitution vs insertion/deletion - ANSWER: substitution alters a single codon,
insertion/deletion can alter many
transition vs transversion - ANSWER: transition is substitution of purine for purine or pyrimidine for
pyrimidine,
transversion is pyrimidine for a purine or purine for a pyrimidine
purine - ANSWER: Adenine and Guanine double ring
pyrimidine - ANSWER: Cytosine and thymine, structure made up of 1 ring
expanding nucleotide repeats - ANSWER: number of copies of set of nucleotides increases from
normal,
genetic testing results may not be definitive,
age of onset, severity of condition
example of human genetic disease caused by nucleotide repeat - ANSWER: CAG repeated,
huntington
types of genetic mutations and their results - ANSWER: forward, reverse, missense, nonsense, silent,
neutral
forward mutation - ANSWER: wild type to mutant type
, reverse mutation - ANSWER: mutant to wild type
missense mutation - ANSWER: amino acid to different amino acid
nonsense mutations - ANSWER: new codon is stop codon, premature termination of translation
silent mutation - ANSWER: codon to synonymous codon
neutral mutation - ANSWER: no change in function
phenotypes effects of mutations - ANSWER: loss of function,
gain of function,
lethal
loss of function mutation - ANSWER: coding sequence is defective,
coding sequence intact but mutation impairs binding of transcription factors to promotors or
enhances,
not deleterious
examples of loss of function mutations - ANSWER: inability to synthesize vitamin C,
pale skin
example of gain of function mutation - ANSWER: lactase persistence
gain of function mutation - ANSWER: protein produced that is not normally present or is expressed
differently
true frequency of mutation is - ANSWER: difficult to detect,
DNA repair mechanisms correct it before next round of replication,
mutation is not detectable in phenotype,
lethal mutations leave no evidence
what causes mutations - ANSWER: spontaneous chemical changes,
spontaneous replication errors,
chemically induced mutations,
radiation
spontaneous replication errors include - ANSWER: tautomeric shifts,
mispairing,
incorporation errors and replication errors,
deletions and insertions
tautomeric shifts - ANSWER: change in chemical structure of base,
spontaneous isomerization of nitrogen base to alternative hydrogen bonding form
deletions and insertions result in - ANSWER: strand slippage results in dropping of base pair or
nonsense (has to happen at right time),
unequal crossing over
wobble base pairing process and result - ANSWER: transition mutation,
DNA strands separate for replication,
thymine on original template strand base pairs with guanine,
at next round of replication,
guanine with cytosine,
transition mutation
transition mutation caused by - ANSWER: wobble base pairing