BIOB51 Test 1 | Summer 2025 Final Verified
Multiple Choice and Conceptual Actual Exam
Questions With Reviewed 100% Correct
Detailed Answers
Guaranteed Pass!!Current Update
1. What is a point mutation? Within coding regions, know how to identify and
describe synonymous, nonsynonymous, and nonsense mutations? - ANSWER
A point mutation is when a single nucleotide changes into another.
Synonymous mutations (or silent mutations) cause the same amino acid to be
added, but may affect slight efficiency changes.
Nonsynonymous (missense) changes the amino acid entirely, and a nonsense
mutation leads to the premature stopping of protein production through a newly
introduced stop codon.
2. What is meant by an 'in-frame' and 'frameshift' mutation.
What is potential impact on the polypeptide? - ANSWER ' In-frame '
mutations are changes to nucleotides within the 3 codon reading frame.
Frameshift: caused by deletions, insertions, or duplications change the entire
protein by shifting the 3 codon reading frame.
■ Changes all downstream codons, leading to a completely different polypeptide
or premature stop codon
■ Nonfuncitonal or trucated protein
,3. Know how to describe and identify duplication, deletion/insertion, inversion,
and translocation - ANSWER Deletions (parts of the chromosomes are
deleted), Inversions (parts of the chromosomes from idential chromatids are
swapped and inverted),
Duplications (a chromatid is elongated by a sudden duplication)
Translocations (One part of a chromatid move to another part, and vice versa,
involving different chromatids i.e. 9 and 22 in cancer patients)
4. What is the difference between cis and trans regulation of gene expression? -
ANSWER Cis regulation is where factors affecting transcription are on the
same chromosome, either upstream or downstream, usually regulatory
sequences, but may also be RNA being synthesized from the DNA while also
acting on the same DNA.
Trans regulation of transcription are proteins and other factors that come from
other chromosomes, or synthesized from the same chromosome however only
enacting while completely separated from it.
5. Understand and be able to describe how gene expression can be regulated?
What is an activator, enhancer, silencer, transcription factor? - ANSWER
An activator is the cis regulator where enhancers, the trans regulators, can
enhance gene expression.
Silencers are regions where trans acting repressors may bind to repress gene
expression.
6. Gene duplications can play two important roles in evolution: - ANSWER 1.
Lead to creation of Pseudogenes
,2. Lead to the creation of new functional genes
7. Loss-of-function mutations are more likely to be found in a duplicated gene
rather than in a gene with only one copy. Why? - ANSWER
8. Paralog - ANSWER copy of a gene caused by a gene duplication event
9. Functional redundancy - ANSWER • The original gene continues to
produce functional protein
• The paralog is often under reduced selection for the original function
• Many possible outcomes
10. Pseudogenes - ANSWER a DNA sequence that resembles a functional
gene but has lost its protein-coding ability or is no longer expressed
• often form after a gene has been duplicated and one or more of the redundant
('extra') copies loses their function • Human genomes have almost 17,032
pseudogenes!
Accumulate mutations more rapidly than functional genes, at a predictable rate
(see next lecture: genetic drift)
• Provide a 'record' of evolutionary history of a taxon
11. Evolution of Venom in Snakes - ANSWER Snake venom genes are related
to genes found in many other organs for different functions
• Some lizards have genes closely related to snake venom genes
, • Venoms now used in snakes started evolving millions of years before snakes
evolved
12. Aneuploidy - ANSWER Chromosomes are duplicated or lost
e.g. Trisomy 21 (leading to Down's Syndrome) Extra full or partial copy of
chromosome 21 (so there are 3)
13. What does the term ploidy refer to? What is diploid? What is haploid? What
is polyploid? - ANSWER Ploidy is how many copies of chromosomes you
have. Diploids (2n) have two copies, ( human = 46)
haploids (1n) have one copies, ( gametes = 23 )
polyploidy (triploid, tetraploid etc.)
14. What is a karyotype? - ANSWER The graphical depiction of all your
chromosomes together.
15. What is RNA? How is RNA different from DNA? What is similar between DNA
and RNA? - ANSWER RNA is a molecule derived from DNA. The
intermediate between DNA and protein, but also for different functions. It's
similar from DNA because of the bases and general structure, however RNA
has uracil instead of thymine, and also has a ribose sugar with two hydroxyl
groups.
16. What are the three main types of RNA? What are their roles? - ANSWER
Messenger RNA (mRNA)
■ Carries genetic code from DNA → ribosomes
Multiple Choice and Conceptual Actual Exam
Questions With Reviewed 100% Correct
Detailed Answers
Guaranteed Pass!!Current Update
1. What is a point mutation? Within coding regions, know how to identify and
describe synonymous, nonsynonymous, and nonsense mutations? - ANSWER
A point mutation is when a single nucleotide changes into another.
Synonymous mutations (or silent mutations) cause the same amino acid to be
added, but may affect slight efficiency changes.
Nonsynonymous (missense) changes the amino acid entirely, and a nonsense
mutation leads to the premature stopping of protein production through a newly
introduced stop codon.
2. What is meant by an 'in-frame' and 'frameshift' mutation.
What is potential impact on the polypeptide? - ANSWER ' In-frame '
mutations are changes to nucleotides within the 3 codon reading frame.
Frameshift: caused by deletions, insertions, or duplications change the entire
protein by shifting the 3 codon reading frame.
■ Changes all downstream codons, leading to a completely different polypeptide
or premature stop codon
■ Nonfuncitonal or trucated protein
,3. Know how to describe and identify duplication, deletion/insertion, inversion,
and translocation - ANSWER Deletions (parts of the chromosomes are
deleted), Inversions (parts of the chromosomes from idential chromatids are
swapped and inverted),
Duplications (a chromatid is elongated by a sudden duplication)
Translocations (One part of a chromatid move to another part, and vice versa,
involving different chromatids i.e. 9 and 22 in cancer patients)
4. What is the difference between cis and trans regulation of gene expression? -
ANSWER Cis regulation is where factors affecting transcription are on the
same chromosome, either upstream or downstream, usually regulatory
sequences, but may also be RNA being synthesized from the DNA while also
acting on the same DNA.
Trans regulation of transcription are proteins and other factors that come from
other chromosomes, or synthesized from the same chromosome however only
enacting while completely separated from it.
5. Understand and be able to describe how gene expression can be regulated?
What is an activator, enhancer, silencer, transcription factor? - ANSWER
An activator is the cis regulator where enhancers, the trans regulators, can
enhance gene expression.
Silencers are regions where trans acting repressors may bind to repress gene
expression.
6. Gene duplications can play two important roles in evolution: - ANSWER 1.
Lead to creation of Pseudogenes
,2. Lead to the creation of new functional genes
7. Loss-of-function mutations are more likely to be found in a duplicated gene
rather than in a gene with only one copy. Why? - ANSWER
8. Paralog - ANSWER copy of a gene caused by a gene duplication event
9. Functional redundancy - ANSWER • The original gene continues to
produce functional protein
• The paralog is often under reduced selection for the original function
• Many possible outcomes
10. Pseudogenes - ANSWER a DNA sequence that resembles a functional
gene but has lost its protein-coding ability or is no longer expressed
• often form after a gene has been duplicated and one or more of the redundant
('extra') copies loses their function • Human genomes have almost 17,032
pseudogenes!
Accumulate mutations more rapidly than functional genes, at a predictable rate
(see next lecture: genetic drift)
• Provide a 'record' of evolutionary history of a taxon
11. Evolution of Venom in Snakes - ANSWER Snake venom genes are related
to genes found in many other organs for different functions
• Some lizards have genes closely related to snake venom genes
, • Venoms now used in snakes started evolving millions of years before snakes
evolved
12. Aneuploidy - ANSWER Chromosomes are duplicated or lost
e.g. Trisomy 21 (leading to Down's Syndrome) Extra full or partial copy of
chromosome 21 (so there are 3)
13. What does the term ploidy refer to? What is diploid? What is haploid? What
is polyploid? - ANSWER Ploidy is how many copies of chromosomes you
have. Diploids (2n) have two copies, ( human = 46)
haploids (1n) have one copies, ( gametes = 23 )
polyploidy (triploid, tetraploid etc.)
14. What is a karyotype? - ANSWER The graphical depiction of all your
chromosomes together.
15. What is RNA? How is RNA different from DNA? What is similar between DNA
and RNA? - ANSWER RNA is a molecule derived from DNA. The
intermediate between DNA and protein, but also for different functions. It's
similar from DNA because of the bases and general structure, however RNA
has uracil instead of thymine, and also has a ribose sugar with two hydroxyl
groups.
16. What are the three main types of RNA? What are their roles? - ANSWER
Messenger RNA (mRNA)
■ Carries genetic code from DNA → ribosomes
