BIO 148
BIO 148 EXAM 2 PRACTICE QUESTIONS WITH
CORRECT ANSWERS 2026 UPDATE
What do activators do? -Correct Answer ✔-turn on transcription at the time & location
the mRNA needs to be made
Where do point mutations usually occur? -Correct Answer ✔-the promoter (which
typically alters amount of gene expression)
What is created from mutations? -Correct Answer ✔-alleles, which creates new proteins
& a new phenotype
Point mutation -Correct Answer ✔-gene mutation in which a single base pair in DNA has
been changed
When do mutations occur? -Correct Answer ✔-during DNA replication
Silent mutation -Correct Answer ✔-A mutation that changes a single nucleotide, but
does NOT change the amino acid created
Missense mutation -Correct Answer ✔-A base-pair substitution that results in a codon
that codes for a different amino acid
Nonsense mutation -Correct Answer ✔-A 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? -Correct Answer ✔-3
tRNA -Correct Answer ✔-an adapter molecule that holds acids in place, posses
anticodons that base pair w/ mRNA (antiparallel, complementary)
5 features of genetic code -Correct Answer ✔-1. 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 -Correct Answer ✔-redundant
BIO 148
, BIO 148
Two distantly related species (like a cow and a yeast) will: -Correct Answer ✔-have
many genes that differ b/w the two species
Two members of same species will: -Correct Answer ✔-share all the same genes, but
may contain different alleles
An individual that is heterozygous for a particular gene has: -Correct Answer ✔-two
different alleles of the gene, w/ each copy located on homologous chromosomes
What links acids? -Correct Answer ✔-peptide bonds b/w carboxyl group of one interacts
w/ amino group of another
Building block of proteins are -Correct Answer ✔-amino acids
A gene duplication followed by many mutations create a new: -Correct Answer ✔-gene
A single point mutation in a gene creates a new: -Correct Answer ✔-allele
If you compare any 2 different amino acids, how will they differ? -Correct Answer ✔-their
R groups will differ
What is a switch activator? -Correct Answer ✔-proteins that bind to a DNA sequence
(switches are DNA sequences)
What is a gene expression? -Correct Answer ✔-the mRNAs that are translated to
proteins
What does adding or removing a base do? -Correct Answer ✔-change the reading
frame of the gene
Does DNA in cells vary? -Correct Answer ✔-NO. The DNA in every single one of your
somatic cells is the same (all 23 chromosomes)
However, the difference is the genes that are expressed
An animal is born w/ a mutation that prevents the expression of the BIO148 protein in
Kidney but does NOT prevent its expression in Liver. Where is this mutation most likely
located? -Correct Answer ✔-in a gene switch
Translation -Correct Answer ✔-mRNA is translated into a sequence of acids of a protein
Which is translated? -Correct Answer ✔-exons
What are ribosomes the sight of? -Correct Answer ✔-protein synthesis
BIO 148
BIO 148 EXAM 2 PRACTICE QUESTIONS WITH
CORRECT ANSWERS 2026 UPDATE
What do activators do? -Correct Answer ✔-turn on transcription at the time & location
the mRNA needs to be made
Where do point mutations usually occur? -Correct Answer ✔-the promoter (which
typically alters amount of gene expression)
What is created from mutations? -Correct Answer ✔-alleles, which creates new proteins
& a new phenotype
Point mutation -Correct Answer ✔-gene mutation in which a single base pair in DNA has
been changed
When do mutations occur? -Correct Answer ✔-during DNA replication
Silent mutation -Correct Answer ✔-A mutation that changes a single nucleotide, but
does NOT change the amino acid created
Missense mutation -Correct Answer ✔-A base-pair substitution that results in a codon
that codes for a different amino acid
Nonsense mutation -Correct Answer ✔-A 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? -Correct Answer ✔-3
tRNA -Correct Answer ✔-an adapter molecule that holds acids in place, posses
anticodons that base pair w/ mRNA (antiparallel, complementary)
5 features of genetic code -Correct Answer ✔-1. 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 -Correct Answer ✔-redundant
BIO 148
, BIO 148
Two distantly related species (like a cow and a yeast) will: -Correct Answer ✔-have
many genes that differ b/w the two species
Two members of same species will: -Correct Answer ✔-share all the same genes, but
may contain different alleles
An individual that is heterozygous for a particular gene has: -Correct Answer ✔-two
different alleles of the gene, w/ each copy located on homologous chromosomes
What links acids? -Correct Answer ✔-peptide bonds b/w carboxyl group of one interacts
w/ amino group of another
Building block of proteins are -Correct Answer ✔-amino acids
A gene duplication followed by many mutations create a new: -Correct Answer ✔-gene
A single point mutation in a gene creates a new: -Correct Answer ✔-allele
If you compare any 2 different amino acids, how will they differ? -Correct Answer ✔-their
R groups will differ
What is a switch activator? -Correct Answer ✔-proteins that bind to a DNA sequence
(switches are DNA sequences)
What is a gene expression? -Correct Answer ✔-the mRNAs that are translated to
proteins
What does adding or removing a base do? -Correct Answer ✔-change the reading
frame of the gene
Does DNA in cells vary? -Correct Answer ✔-NO. The DNA in every single one of your
somatic cells is the same (all 23 chromosomes)
However, the difference is the genes that are expressed
An animal is born w/ a mutation that prevents the expression of the BIO148 protein in
Kidney but does NOT prevent its expression in Liver. Where is this mutation most likely
located? -Correct Answer ✔-in a gene switch
Translation -Correct Answer ✔-mRNA is translated into a sequence of acids of a protein
Which is translated? -Correct Answer ✔-exons
What are ribosomes the sight of? -Correct Answer ✔-protein synthesis
BIO 148
