Biotechnology Quiz
Questions: 16 · 10 minutes
1. Which statement best defines biotechnology?
The use of organisms, cells, or biological systems to develop products or processes
The classification of organisms solely by their physical features
The study of chemical elements that do not occur in living systems
The replacement of all biological production methods with synthetic chemistry
2. An enzyme performs well at pH 7 but has much lower activity at pH 4. What is the best explanation?
The lower pH changes substrate concentration but cannot affect the enzyme
The enzyme is consumed more rapidly because it acts as a reactant
Every enzyme is completely destroyed at any non-neutral pH
The pH change can alter active-site ionization or shape, reducing catalysis
3. A sterilized fermentation medium remains clear until immediately after a microbial culture is transferred into it. Several batches then become contaminated. What is the most likely source?
The inoculum or an aseptic-transfer procedure
An insufficient concentration of carbon in the medium
The bioreactor’s external cooling jacket
A dissolved-oxygen level that is too high
4. How does pasteurization differ from sterilization?
Pasteurization removes only viruses, while sterilization removes only bacteria
Pasteurization always uses a higher temperature than sterilization
Pasteurization reduces targeted pathogens and spoilage organisms without necessarily eliminating all microbes
Pasteurization guarantees the destruction of every microbial cell and spore
5. A glucose biosensor uses an enzyme to react with glucose and an electrode to convert the reaction into an electrical signal. Which component is the transducer?
The glucose in the sample
The electrode that converts the reaction into a measurable signal
The enzyme that recognizes glucose
The calibration solution used to check the device
6. Scientists are designing a production microorganism that should not survive if it escapes from a facility. Which modification most directly supports this goal?
Giving it a stronger promoter for faster product formation
Adding an antibiotic-resistance marker without another safeguard
Expanding the range of nutrients it can use in natural environments
Making it dependent on a nutrient that is supplied in the facility but absent in nature
7. A PCR negative control contains all reaction components except template DNA, but it still produces the expected-sized band. What does this most strongly suggest?
The sample definitely lacked the target DNA
The primers have proven that they bind only to the intended target
The control or another reaction component was contaminated with target DNA
Amplification is expected whenever polymerase is included
8. A company wants bacteria to produce human insulin. Which step makes this possible?
Exposing the bacteria to insulin so they learn to reproduce it
Introducing a DNA sequence encoding human insulin into the bacteria
Removing every plasmid and chromosome from the bacteria
Mixing bacterial proteins directly with human pancreatic cells
9. After bacteria are transformed with a plasmid carrying an antibiotic-resistance marker, why are they grown on medium containing that antibiotic?
To force all bacterial cells to create an identical new plasmid
To select for cells that acquired and express the plasmid marker
To make the target protein visible without further testing
To prevent transformed cells from reproducing too quickly
10. During an aerobic microbial fermentation, dissolved oxygen falls below the target level as the culture grows. Which adjustment would most directly improve oxygen transfer?
Lowering airflow into the bioreactor
Adding antifoam without changing any other condition
Increasing aeration or agitation within safe operating limits
Stopping pH measurement for the remainder of the run
11. What is the main purpose of the polymerase chain reaction, or PCR?
To separate proteins according to molecular mass
To grow microorganisms without a nutrient medium
To amplify a selected region of DNA
To translate messenger RNA directly into lipids
12. Which feature most clearly distinguishes a continuous culture from a batch culture?
The culture must use photosynthetic microorganisms
Fresh medium is added while culture is removed to maintain a working volume
All nutrients are supplied only once at the beginning
The product must remain inside the microbial cells
13. In CRISPR-Cas9 gene editing, what primarily directs Cas9 to the intended DNA sequence?
A lipid that dissolves the unwanted DNA sequence
A ribosome carrying the corresponding amino acid
An antibody that recognizes the target chromosome
A guide RNA with a sequence complementary to the target region
14. A dairy processor attaches lactase enzymes to insoluble beads and passes milk over them. What is a major advantage of immobilizing the enzyme?
The enzyme can be separated from the product and reused more easily
The enzyme becomes a living organism that can reproduce
The enzyme no longer depends on temperature or pH
The enzyme permanently changes lactose into a catalyst
15. Which example best illustrates bioremediation?
Separating DNA fragments according to size in a gel
Using a microscope to count cells in uncontaminated water
Adding artificial flavor compounds to fermented food
Using microorganisms to break down pollutants in contaminated soil
16. In a biotechnology production process, what does downstream processing generally involve?
Recovering and purifying the desired product after cultivation
Preparing nutrients and sterilizing the growth medium
Optimizing gene expression inside the production organism
Selecting the organism before cultivation begins