Final Exam Questions and All Correct
Answers 2025-2026 Updated.
What structure is indicated by: 10A, 15T, 3G, 7C? - Answer Single-stranded DNA.
Negative control means that a regulator molecule is - Answer bound and transcription is
inhibited AND removed and transcription begins.
DNA is characterized by which of the following feature(s)? - Answer Deoxyribose AND
Thymine.
All fungi have __________ in their cell walls - Answer chitin.
The placement of the amino acid during translation is determined by the - Answer
complementarity of the codon-anticodon.
Polymerase chain reaction (PCR) can be used to perform DNA sequencing reactions. In this case,
are 2 primers (a forward and a reverse) necessary? - Answer No; dideoxynucleotide
sequencing depends on different length fragments being formed and then separated based on
size and this can take place with only a specific forward primer OR a specific reverse primer.
Treponema and Borrelia - Answer are spirochetes.
Coliforms - Answer A. are an informal grouping of enterics.
B. ferment lactose.
C. includes E. coli.
D. are used as indicators of fecal contamination.
->E. All of the choices are correct.
A common way to identify E. coli that carry the desired recombinant DNA is by using a - Answer
probe
Thymine dimer-containing section of DNA is cut out, resynthesized and sealed - Answer
Excision repair
,Catastrophic DNA damage caused by ultraviolet light can be survived by the cell with this -
Answer SOS repair
Non-constituitive system with visible light energy breaking covalent T-T bonds - Answer
Photoreactivation
Multiple enzymes may repair an A-C error left unrecognized by DNA polymerase - Answer
Mismatch repair
A "spell check" function by the normal replication enzyme to ensure fidelity - Answer
Proofreading
Outside of living cells, viruses are - Answer metabolically inert.
The size of the amplified DNA fragment generated during PCR is determined by - Answer the
locations to which the primers anneal.
Direct selection involves inoculating cells onto growth media upon which - Answer the
mutant, but not the parental cell type, will grow.
When DNA probes are used to identify bacterial DNA similarities by hybridization, the probe
DNA is heated and the template DNA is treated to separate the 2 strands. Why would the probe
DNA be heated? - Answer The probe DNA is single stranded but it may have folded back on
itself and formed portions that are double-stranded; heating it up breaks any possible hydrogen
bonds that may have formed, returning it to a single-stranded state prior to hybridization.
Strain differences are helpful in - Answer tracing the source of outbreaks of disease.
Bacteria use ___________ attached to the polymerase and they direct RNA polymerase to
promoters; eukaryotic cells use __________ that instead attach directly to the DNA first. -
Answer sigma factors; transcription factors
Disagreements between conclusions obtained from rDNA data and other techniques may be
explained by - Answer horizontal DNA transfer.
The Ames test is useful as a rapid screening test to identify those compounds that - Answer
have a high probability of being carcinogenic.
,To increase the proportion of mutants in a population of bacteria one may use - Answer
penicillin enrichment.
Endospores - Answer are a dormant form of a bacterium formed by members of medically
relevant groups of bacteria.
To maximize the number of thymine dimer mutations following UV exposure, should you keep a
plate of fungal cells in the dark, in the light, or does it matter at all? - Answer It does not
matter; fungal cells do not possess the enzymes needed for photorepair of thymine dimers
because these enzymes are only found in prokaryotes.
Protozoan classification is based on their means of - Answer locomotion
Post-translational modification may include - Answer the folding of the protein, often with
the aid of chaperones AND the removal of the signal sequence
Which of the following is not true about mismatch repair? - Answer It removes both strands
in the mismatch area.
Comparatively greater energy is released when - Answer oxygen is the final electron
acceptor.
The viral envelope resembles the - Answer eukaryotic cell membrane.
Propionibacterium - Answer produces propionic acid.
Anoxygenic phototrophs - Answer use hydrogen sulfide or organic compounds as a source of
electrons.
Phages that can either replicate and cause cell lysis or can integrate their DNA into the host DNA
are called - Answer temperate phages.
Wild Type - Answer Bacteria species isolated from a salt marsh
Genotype - Answer F+
Auxotroph - Answer Requires histidine amino acid addition to the medium for growth
, Phenotype - Answer Colonies on agar have a purple color
Prototroph - Answer Not fastidious when cultivated
In order to get around the lack of ability of prokaryotes to remove introns from precursor RNA,
it may be necessary to - Answer turn mRNA into cDNA.
In E. coli 0157:H7 the 0157:H7 refers to the - Answer specific LPS and flagella type present.
Why is it a good idea for a bacterial cell to be able to utilize glucose FIRST as an energy source
(until it is used up), THEN switch to lactose? - Answer Glucose is an easier compound to
break down and obtain energy from than lactose AND it's about conservation of energy-why
expend the energy to make the extra enzymes for breaking down lactose when glucose is right
there and doesn't need extra enzymes for breakdown
Operon(s) in bacteria - Answer refers to a group of genes that are coordinately controlled
AND involve polycistronic mRNA.
The specific sequence of nucleotides in the DNA to which the RNA polymerase binds is the -
Answer promoter region.
A student complains that it makes no sense to worry about coliform bacteria in water, since we
naturally possess harmless coliforms in our intestines anyway. Why do regulatory agencies
worry about coliform bacteria in water supplies, then? - Answer Not all coliforms are
harmless and symbiotic with human beings and some may carry genes/proteins that can make
them dangerous to humans; it is best to keep coliforms OUT of our drinking water, since it is
difficult to identify which ones might be harmless and which ones might be harmful.
Strong chemical mutagens may be used to treat cancer cells. Is this a good idea or a bad idea? -
Answer The idea is both good and bad; the mutagens are very good at killing cancer cells but
depending upon the mode of administration, they could also be a danger to non-cancerous
cells.
Single-celled eukaryotic organisms that lack chlorophyll are called - Answer protozoa.
The substitution of a single base within a gene's DNA sequence may result in any one of the
following except: - Answer a missense mutation.
-> WRONG