BIO 148 EXAM 2 UKY QUESTIONS
AND ANSWERS 2026
What do activators do? - ANSWERSturn on transcription at the time & location the
mRNA needs to be made
Where do point mutations usually occur? - ANSWERSthe promoter (which typically
alters amount of gene expression)
What is created from mutations? - ANSWERSalleles, which creates new proteins & a
new phenotype
Point mutation - ANSWERSgene mutation in which a single base pair in DNA has been
changed
When do mutations occur? - ANSWERSduring DNA replication
Silent mutation - ANSWERSA mutation that changes a single nucleotide, but does NOT
change the amino acid created
Missense mutation - ANSWERSA base-pair substitution that results in a codon that
codes for a different amino acid
Nonsense mutation - ANSWERSA mutation that changes an amino acid codon to 1 of
the 3 stop codons, resulting in a shorter and usually nonfunctional protein "STOP that
nonsense!"
How many tRNA bonding sights do ribosomes have? - ANSWERS3
tRNA - ANSWERSan adapter molecule that holds acids in place, posses anticodons
that base pair w/ mRNA (antiparallel, complementary)
5 features of genetic code - ANSWERS1. Redundant (> 1 codon/acid)
2. Unambiguous (1 codon= 1 acid)
3. Non-overlapping (after AUG, reads every 3 bases)
4. Nearly universal (all use ATCG)
5. Conservative (when several codons code for the same acid the first 2 bases are
identical)
Genetic code is - ANSWERSredundant
Two distantly related species (like a cow and a yeast) will: - ANSWERShave many
genes that differ b/w the two species
AND ANSWERS 2026
What do activators do? - ANSWERSturn on transcription at the time & location the
mRNA needs to be made
Where do point mutations usually occur? - ANSWERSthe promoter (which typically
alters amount of gene expression)
What is created from mutations? - ANSWERSalleles, which creates new proteins & a
new phenotype
Point mutation - ANSWERSgene mutation in which a single base pair in DNA has been
changed
When do mutations occur? - ANSWERSduring DNA replication
Silent mutation - ANSWERSA mutation that changes a single nucleotide, but does NOT
change the amino acid created
Missense mutation - ANSWERSA base-pair substitution that results in a codon that
codes for a different amino acid
Nonsense mutation - ANSWERSA mutation that changes an amino acid codon to 1 of
the 3 stop codons, resulting in a shorter and usually nonfunctional protein "STOP that
nonsense!"
How many tRNA bonding sights do ribosomes have? - ANSWERS3
tRNA - ANSWERSan adapter molecule that holds acids in place, posses anticodons
that base pair w/ mRNA (antiparallel, complementary)
5 features of genetic code - ANSWERS1. Redundant (> 1 codon/acid)
2. Unambiguous (1 codon= 1 acid)
3. Non-overlapping (after AUG, reads every 3 bases)
4. Nearly universal (all use ATCG)
5. Conservative (when several codons code for the same acid the first 2 bases are
identical)
Genetic code is - ANSWERSredundant
Two distantly related species (like a cow and a yeast) will: - ANSWERShave many
genes that differ b/w the two species
