BIO 340 FINAL EXAM QUESTIONS
WITH CORRECT SOLUTIONS||A+
GRADED||UPDATED 2026/2027
SYLLABUS||<<RECENT
VERSION>>
Which of the following types of mutation is a transition - ANSWER ✓ A-->G
-can't be purine to purine or pyrimidine to pyrimidine)
Which of the following types of mutation is a transvehrsion? - ANSWER ✓ C--
>G
-can't be purine to pyrimidine or pyrimidine to purine)
Silent mutation - ANSWER ✓ does not change protein sequence
missense mutation - ANSWER ✓ results in one amino acid change in a protein
sequence
nonsense mutation - ANSWER ✓ results in truncated protein sequence due to
stop codon
frameshift mutation - ANSWER ✓ results in many amino acids changes
downstream of the mutation and/or truncated protein
Which class of point mutation produces a product with the same amino acid
sequence as the wild-type polypeptide? - ANSWER ✓ silent
-silent mutation are nucleotides substitutions that result in no change in the
polypeptide sequence encoded by the mutant allele
Which class of point mutation essentially always results in a mutant phenotype? -
ANSWER ✓ frameshift
,-frameshift mutations alter the translational reading frame so that the entire amino
acid sequence is altered beyond the sire of the mutation (nucleotide insertion or
deletion)
what caused spontaneous mutations? - ANSWER ✓ -nucleotides structural
changes
-(tautomerism)
-nucleotide structural damage
- (lesions)
-DNA strand slippage
-(replication error)
*nucleotide structural isomerism and sessions occur many thousands times in each
cells every 24 hours* - ANSWER ✓ -however, most events are quickly revered or
repaired and do not result in DNA mutation
tautomers
*most common form of replication error* - ANSWER ✓ when nucleotide bases
can occasionally convert between alternative structures
radiation induced damage (usually uv) - ANSWER ✓ photo reactive
(=photoreactive repair)
UV repair (by nucleotide excision)
mismatch repair - ANSWER ✓ -mismatch repair in E. coli
-nucleotide base excision
-nucleotide excision (non-photoreactivation UV repair)
translation DNA synthesis - ANSWER ✓
double strand break repair - ANSWER ✓ -non homologous end joining (NHEJ)
-synthesis-dependent strand annealing (SDSA)
nucleotide base excision repair - ANSWER ✓ removes modified bases such as
hypoxanthine and 5-methylcytosine
What type of spontaneous mutation is fixed by nucleotide base excision repair? -
ANSWER ✓ deamination
,- hypoxanthine is the deaminated form of adenine; uracil is the deaminated form of
5-methylcytosine
nucleotide excision repair pt. 2 - ANSWER ✓ fixes bulky modifications such as
thymine dimers caused by radiation or O⁶-ethylguanine caused by alkylating agents
double-stranded break repair - ANSWER ✓ two types
-non-homologous end-jointing (NHEJ)
-synthesis-dependent strand annealing (SDSA)
synthesis dependent strand annealing (SDSA) - ANSWER ✓ -shares proteins
with recombination
-after replication before mitosis
-accurate
Autosomal Recessive - ANSWER ✓ An affected individual has two copies of a
mutant gene on a pair of autosomal chromosomes
Autosomal - ANSWER ✓ Chromosomes that are NOT sex chromosomes
Autosomal Dominant - ANSWER ✓ An affected individual has one copy of a
mutant gene and one normal gene on a pair of autosomal chromosomes
Recurrence Risk - ANSWER ✓ Probability that parents will produce a child with
a genetic disease
Haplosufficient - ANSWER ✓ Alleles that carry enough genetic product to
function alone
Haploinsufficient - ANSWER ✓ Alleles that do NOT carry enough genetic
product to function alone
Incomplete Dominance - ANSWER ✓ A form of intermediate inheritance in
which one allele for a specific trait is not completely expressed over its paired
allele
Codominance - ANSWER ✓ When heterozygotes express the phenotype of both
their alleles
, Gene Interaction - ANSWER ✓ Occurs when two or more genes affect the same
phenotype, by influencing a common pathway
Polygenic Traits - ANSWER ✓ Traits controlled by two or more genes (height,
skin color)
Epistasis - ANSWER ✓ Two separate genes control one trait, but one gene masks
the expression of the other gene
Recessive Lethal - ANSWER ✓ Lethal allele expressed only in the recessive
homozygote
Pleiotropy - ANSWER ✓ The control of more than one phenotypic characteristic
by a single gene
Diploid - ANSWER ✓ Containing two complete sets of chromosomes, one from
each parent
Chromatids - ANSWER ✓ Two identical chromosomes that split and contain the
same genetic material
Centromere - ANSWER ✓ Area where the chromatids of a chromosome are
attached
Homologous Chromosomes - ANSWER ✓ Chromosomes that have the same
sequence of genes and the same structure
Mitosis (1->2) - ANSWER ✓ Cell division in which the nucleus divides into
nuclei containing the same number of chromosomes
Meiosis (1->4) - ANSWER ✓ Cell division that produces reproductive cells in
sexually reproducing organisms
Sex-Limited Inheritance - ANSWER ✓ Autosomal traits in which one phenotype
is limited to one sex
WITH CORRECT SOLUTIONS||A+
GRADED||UPDATED 2026/2027
SYLLABUS||<<RECENT
VERSION>>
Which of the following types of mutation is a transition - ANSWER ✓ A-->G
-can't be purine to purine or pyrimidine to pyrimidine)
Which of the following types of mutation is a transvehrsion? - ANSWER ✓ C--
>G
-can't be purine to pyrimidine or pyrimidine to purine)
Silent mutation - ANSWER ✓ does not change protein sequence
missense mutation - ANSWER ✓ results in one amino acid change in a protein
sequence
nonsense mutation - ANSWER ✓ results in truncated protein sequence due to
stop codon
frameshift mutation - ANSWER ✓ results in many amino acids changes
downstream of the mutation and/or truncated protein
Which class of point mutation produces a product with the same amino acid
sequence as the wild-type polypeptide? - ANSWER ✓ silent
-silent mutation are nucleotides substitutions that result in no change in the
polypeptide sequence encoded by the mutant allele
Which class of point mutation essentially always results in a mutant phenotype? -
ANSWER ✓ frameshift
,-frameshift mutations alter the translational reading frame so that the entire amino
acid sequence is altered beyond the sire of the mutation (nucleotide insertion or
deletion)
what caused spontaneous mutations? - ANSWER ✓ -nucleotides structural
changes
-(tautomerism)
-nucleotide structural damage
- (lesions)
-DNA strand slippage
-(replication error)
*nucleotide structural isomerism and sessions occur many thousands times in each
cells every 24 hours* - ANSWER ✓ -however, most events are quickly revered or
repaired and do not result in DNA mutation
tautomers
*most common form of replication error* - ANSWER ✓ when nucleotide bases
can occasionally convert between alternative structures
radiation induced damage (usually uv) - ANSWER ✓ photo reactive
(=photoreactive repair)
UV repair (by nucleotide excision)
mismatch repair - ANSWER ✓ -mismatch repair in E. coli
-nucleotide base excision
-nucleotide excision (non-photoreactivation UV repair)
translation DNA synthesis - ANSWER ✓
double strand break repair - ANSWER ✓ -non homologous end joining (NHEJ)
-synthesis-dependent strand annealing (SDSA)
nucleotide base excision repair - ANSWER ✓ removes modified bases such as
hypoxanthine and 5-methylcytosine
What type of spontaneous mutation is fixed by nucleotide base excision repair? -
ANSWER ✓ deamination
,- hypoxanthine is the deaminated form of adenine; uracil is the deaminated form of
5-methylcytosine
nucleotide excision repair pt. 2 - ANSWER ✓ fixes bulky modifications such as
thymine dimers caused by radiation or O⁶-ethylguanine caused by alkylating agents
double-stranded break repair - ANSWER ✓ two types
-non-homologous end-jointing (NHEJ)
-synthesis-dependent strand annealing (SDSA)
synthesis dependent strand annealing (SDSA) - ANSWER ✓ -shares proteins
with recombination
-after replication before mitosis
-accurate
Autosomal Recessive - ANSWER ✓ An affected individual has two copies of a
mutant gene on a pair of autosomal chromosomes
Autosomal - ANSWER ✓ Chromosomes that are NOT sex chromosomes
Autosomal Dominant - ANSWER ✓ An affected individual has one copy of a
mutant gene and one normal gene on a pair of autosomal chromosomes
Recurrence Risk - ANSWER ✓ Probability that parents will produce a child with
a genetic disease
Haplosufficient - ANSWER ✓ Alleles that carry enough genetic product to
function alone
Haploinsufficient - ANSWER ✓ Alleles that do NOT carry enough genetic
product to function alone
Incomplete Dominance - ANSWER ✓ A form of intermediate inheritance in
which one allele for a specific trait is not completely expressed over its paired
allele
Codominance - ANSWER ✓ When heterozygotes express the phenotype of both
their alleles
, Gene Interaction - ANSWER ✓ Occurs when two or more genes affect the same
phenotype, by influencing a common pathway
Polygenic Traits - ANSWER ✓ Traits controlled by two or more genes (height,
skin color)
Epistasis - ANSWER ✓ Two separate genes control one trait, but one gene masks
the expression of the other gene
Recessive Lethal - ANSWER ✓ Lethal allele expressed only in the recessive
homozygote
Pleiotropy - ANSWER ✓ The control of more than one phenotypic characteristic
by a single gene
Diploid - ANSWER ✓ Containing two complete sets of chromosomes, one from
each parent
Chromatids - ANSWER ✓ Two identical chromosomes that split and contain the
same genetic material
Centromere - ANSWER ✓ Area where the chromatids of a chromosome are
attached
Homologous Chromosomes - ANSWER ✓ Chromosomes that have the same
sequence of genes and the same structure
Mitosis (1->2) - ANSWER ✓ Cell division in which the nucleus divides into
nuclei containing the same number of chromosomes
Meiosis (1->4) - ANSWER ✓ Cell division that produces reproductive cells in
sexually reproducing organisms
Sex-Limited Inheritance - ANSWER ✓ Autosomal traits in which one phenotype
is limited to one sex
