Q.1 Which material is most commonly used for the transparent walls of a photobioreactor?
Glass
Stainless steel
Aluminum
PVC
Explanation - Glass offers high optical clarity, chemical resistance, and can be sterilized easily, making it ideal for light‑dependent bioreactors.
Correct answer is: Glass
Q.2 What property of stainless steel makes it popular for bioreactor vessels?
High electrical conductivity
Corrosion resistance
Low melting point
Transparency
Explanation - Stainless steel resists oxidation and microbial fouling, which is critical in wet, often acidic bioprocesses.
Correct answer is: Corrosion resistance
Q.3 Which of the following polymers is most suitable for constructing a disposable bioreactor?
Polypropylene
PVC
Polystyrene
Aluminum
Explanation - Polypropylene is chemically inert, inexpensive, and can be injection molded into disposable vessels.
Correct answer is: Polypropylene
Q.4 Which material is preferred for the construction of a bioreactor that requires sterilization by autoclaving?
Polystyrene
Glass
PVC
Wood
Explanation - Glass withstands the high temperature and pressure of autoclaves without deforming or leaching substances.
Correct answer is: Glass
Q.5 What is the main advantage of using titanium in bioreactor construction?
Low cost
Excellent electrical conductivity
Corrosion resistance and biocompatibility
High thermal conductivity
Explanation - Titanium resists corrosion in harsh media and does not release toxic ions, important for sensitive cell cultures.
Correct answer is: Corrosion resistance and biocompatibility
Q.6 Which construction technique allows rapid prototyping of bioreactor parts?
CNC machining
Injection molding
3D printing
Welding
Explanation - 3D printing enables quick creation of complex geometries without extensive tooling.
Correct answer is: 3D printing
Q.7 Why is polyethylene often avoided in bioreactor construction?
It is too expensive
It degrades under UV light
It is highly porous
It reacts with most chemicals
Explanation - Polyethylene can break down and release contaminants when exposed to UV, compromising sterility.
Correct answer is: It degrades under UV light
Q.8 Which material provides the best combination of optical transparency and chemical resistance for photobioreactors?
Polycarbonate
Polystyrene
PVC
Aluminum
Explanation - Polycarbonate is both optically clear and resistant to many chemicals, making it suitable for light‑based systems.
Correct answer is: Polycarbonate
Q.9 What is a key consideration when selecting a material for a bioreactor that will be used for fermentation of acidic media?
Electrical conductivity
Thermal expansion coefficient
Corrosion resistance
Weight
Explanation - Acidic media can corrode many materials; choosing corrosion‑resistant alloys prevents contamination and leakage.
Correct answer is: Corrosion resistance
Q.10 Which of the following materials is commonly used for disposable bioreactor bags?
Polyethylene terephthalate (PET)
Glass
Aluminum foil
PVC
Explanation - PET is inexpensive, chemically inert, and can be molded into flexible bags for single‑use bioreactors.
Correct answer is: Polyethylene terephthalate (PET)
Q.11 Why is glass often chosen over plastic for large‑scale bioreactor vessels?
Higher thermal conductivity
Lower cost
Greater mechanical strength at scale
Better optical properties
Explanation - Glass can withstand the pressure and volume of large bioreactors better than most plastics without warping.
Correct answer is: Greater mechanical strength at scale
Q.12 Which property is NOT a reason for selecting stainless steel 316 for bioreactor construction?
High corrosion resistance in chlorides
Low magnetic permeability
High biocompatibility
High electrical conductivity
Explanation - While stainless steel does conduct electricity, its primary advantages in bioreactors are corrosion resistance and biocompatibility, not conductivity.
Correct answer is: High electrical conductivity
Q.13 Which material is preferred for constructing a bioreactor that must be sterilized by gamma irradiation?
Glass
PVC
Polyethylene
Aluminum
Explanation - Polyethylene can endure gamma irradiation without significant structural degradation, unlike glass or metals that may crack.
Correct answer is: Polyethylene
Q.14 What is the main advantage of using a polycarbonate shell for a small photobioreactor?
It is cheaper than glass
It is lighter and easier to handle
It is electrically conductive
It has a higher melting point
Explanation - Polycarbonate offers optical clarity while being much lighter than glass, simplifying handling and mounting.
Correct answer is: It is lighter and easier to handle
Q.15 Which process is most suitable for producing high‑precision metal bioreactor components?
Casting
CNC machining
3D printing
Molding
Explanation - CNC machining provides tight tolerances and smooth surfaces necessary for fluid dynamics in bioreactors.
Correct answer is: CNC machining
Q.16 Why is it important to avoid using plastics that contain BPA in bioreactor construction?
They are too expensive
BPA can leach and contaminate cultures
They are not transparent
They are too brittle
Explanation - BPA is a toxic compound that can leach into the culture medium, affecting cell viability and product safety.
Correct answer is: BPA can leach and contaminate cultures
Q.17 Which material is best suited for a bioreactor that needs to be cleaned by chemical disinfectants repeatedly?
Aluminum
PVC
Stainless steel
Polyurethane
Explanation - Stainless steel resists attack from most disinfectants, ensuring longevity and cleanliness.
Correct answer is: Stainless steel
Q.18 What is the main reason for using borosilicate glass in small‑scale bioreactors?
It is transparent to UV
It has low thermal expansion and high chemical resistance
It is cheap
It conducts electricity well
Explanation - Borosilicate glass withstands thermal shock and chemical exposure, maintaining structural integrity.
Correct answer is: It has low thermal expansion and high chemical resistance
Q.19 Which of the following materials is commonly used for the construction of disposable bioreactor membranes?
Polymethyl methacrylate (PMMA)
Silicone rubber
Aluminum foil
Glass fiber
Explanation - Silicone is flexible, chemically inert, and can be sterilized, making it ideal for membranes.
Correct answer is: Silicone rubber
Q.20 Which material property is critical when designing a bioreactor that will operate at temperatures above 80 °C?
Electrical conductivity
High tensile strength
Low thermal conductivity
Transparency
Explanation - Materials must maintain structural integrity at high temperatures to prevent leaks or ruptures.
Correct answer is: High tensile strength
Q.21 What is the primary reason for selecting polycarbonate over PET in photobioreactor windows?
Higher chemical resistance to alkaline media
Higher optical transmittance across UV–visible range
Lower cost
Greater flexibility
Explanation - Polycarbonate transmits a broader spectrum of light, essential for photobioreactors that rely on specific wavelengths.
Correct answer is: Higher optical transmittance across UV–visible range
Q.22 Which construction material allows the easiest integration of sensors into the bioreactor wall?
Glass
PVC
Aluminum
Polystyrene
Explanation - Glass can be sealed around sensor leads with minimal interference, maintaining sterility.
Correct answer is: Glass
Q.23 What is the main drawback of using aluminum for bioreactor vessels?
High cost
Corrosion in alkaline media
Poor optical properties
High density
Explanation - Aluminum forms a brittle oxide layer that can flake in strong bases, contaminating cultures.
Correct answer is: Corrosion in alkaline media
Q.24 Which polymer is typically used for the construction of disposable bioreactor flasks?
Polypropylene
Polystyrene
PVC
Polyethylene
Explanation - Polypropylene is chemically inert, heat‑resistant, and inexpensive for single‑use flasks.
Correct answer is: Polypropylene
Q.25 Why are glass‑fiber reinforced composites avoided in bioreactor construction?
They are too heavy
They leach silica into the culture medium
They are not chemically resistant
They are too transparent
Explanation - Glass fibers can release particles that contaminate cultures, compromising product quality.
Correct answer is: They leach silica into the culture medium
Q.26 Which of the following metals is known for excellent corrosion resistance in chlorinated water?
Stainless steel 316
Stainless steel 304
Titanium alloy
Aluminum alloy
Explanation - 316 contains molybdenum, enhancing resistance to chloride‑induced pitting.
Correct answer is: Stainless steel 316
Q.27 What is a key advantage of using 3D printed PETG for disposable bioreactor parts?
It is electrically conductive
It can be printed at low temperatures
It is chemically resistant and can be sterilized by UV
It is highly opaque
Explanation - PETG resists many solvents and withstands UV sterilization, suitable for disposable components.
Correct answer is: It is chemically resistant and can be sterilized by UV
Q.28 Which material is best suited for bioreactor walls that need to be transparent to infrared light?
Glass
Polyethylene
Polystyrene
PVC
Explanation - Glass transmits IR wavelengths while resisting high temperatures and chemicals.
Correct answer is: Glass
Q.29 Which of these materials is commonly used for the construction of bioreactor agitator impellers?
Titanium
PVC
Glass
Aluminum
Explanation - Titanium impellers resist corrosion from aggressive media while remaining strong under agitation.
Correct answer is: Titanium
Q.30 Which property is NOT important when selecting a material for a bioreactor that will undergo frequent sterilization cycles?
Chemical inertness
High thermal conductivity
Mechanical strength
Low permeability to gases
Explanation - While thermal conductivity matters for heat transfer, it is less critical than chemical resistance and mechanical integrity for sterilization.
Correct answer is: High thermal conductivity
Q.31 Which of the following materials can be used to construct a disposable bioreactor bag that must be sterilized by ethylene oxide?
PVC
Polyethylene
Polycarbonate
Glass fiber
Explanation - Polyethylene is compatible with ethylene oxide sterilization without degrading.
Correct answer is: Polyethylene
Q.32 Which material is most appropriate for a bioreactor that requires optical monitoring by laser light?
Polystyrene
Glass
PVC
Aluminum
Explanation - Glass provides minimal light scattering and high transmission for precise laser measurements.
Correct answer is: Glass
Q.33 Which construction method is best for creating a large, complex‑shaped bioreactor vessel?
CNC machining
Injection molding
Casting
Extrusion
Explanation - Casting allows the creation of large, intricate shapes that would be difficult to machine or mold.
Correct answer is: Casting
Q.34 Which of these materials is ideal for the construction of a bioreactor that will be used in a highly alkaline environment?
Stainless steel 316
Aluminum alloy
PVC
Polycarbonate
Explanation - PVC maintains integrity and resistance in high pH conditions, whereas metals may corrode.
Correct answer is: PVC
Q.35 What is the advantage of using a glass‑sealed bioreactor for fermentation?
Lower cost
Higher optical transparency for monitoring
Easier cleaning
Better thermal conduction
Explanation - Glass seals allow visual inspection and optical measurement without compromising sterility.
Correct answer is: Higher optical transparency for monitoring
Q.36 Which material is preferred for building a bioreactor that will be sterilized by ionizing radiation?
Aluminum
Glass
PVC
Polyethylene
Explanation - Polyethylene tolerates ionizing radiation without cracking or emitting toxic by‑products.
Correct answer is: Polyethylene
Q.37 Which of the following properties is critical for a bioreactor material in a continuous culture system?
High electrical resistivity
Chemical resistance to continuous exposure
Low optical absorption
High thermal expansion
Explanation - Continuous systems expose materials to media for extended periods; resistance prevents leaching.
Correct answer is: Chemical resistance to continuous exposure
Q.38 Which material would you use for a disposable bioreactor that needs to be sterilized by UV light?
PVC
Glass
Polyethylene
Aluminum
Explanation - PVC can be sterilized by UV and does not absorb or scatter the light excessively.
Correct answer is: PVC
Q.39 What is a primary drawback of using polypropylene for a large bioreactor vessel?
It is too expensive
It cannot be sterilized by autoclaving
It has low mechanical strength at high temperatures
It is not chemically resistant
Explanation - Polypropylene softens above 60 °C, limiting its use in high‑temperature bioprocesses.
Correct answer is: It has low mechanical strength at high temperatures
Q.40 Which of the following is not a typical material used for bioreactor tubing?
PEEK
PVC
Silicone
Aluminum
Explanation - Aluminum is not used for tubing because it can corrode and is not flexible.
Correct answer is: Aluminum
Q.41 What material property is most important for a bioreactor that will be used in a highly radioactive environment?
Low neutron absorption cross‑section
High thermal conductivity
High optical transparency
High electrical conductivity
Explanation - Materials must not capture neutrons, which could produce additional radiation hazards.
Correct answer is: Low neutron absorption cross‑section
Q.42 Which material is best suited for the construction of a disposable bioreactor that needs to be autoclaved?
PVC
Polystyrene
Polypropylene
Glass fiber
Explanation - Polypropylene withstands autoclave temperatures without deformation.
Correct answer is: Polypropylene
Q.43 Why is borosilicate glass preferred over soda‑lime glass for bioreactors?
It is cheaper
It has lower thermal expansion and higher chemical resistance
It is lighter
It is transparent to infrared light
Explanation - Borosilicate glass resists thermal shock and chemical attack better than soda‑lime glass.
Correct answer is: It has lower thermal expansion and higher chemical resistance
Q.44 Which construction method is most suitable for mass production of disposable bioreactor bags?
Injection molding
3D printing
CNC machining
Casting
Explanation - Injection molding enables high‑speed, low‑cost production of large quantities of identical parts.
Correct answer is: Injection molding
Q.45 What is a major benefit of using a titanium impeller in a bioreactor?
Low cost
High corrosion resistance and biocompatibility
High electrical conductivity
High thermal expansion
Explanation - Titanium remains stable in aggressive media and does not release harmful ions into the culture.
Correct answer is: High corrosion resistance and biocompatibility
Q.46 Which material is ideal for constructing a bioreactor that will be used with anaerobic bacteria?
Stainless steel 316
PVC
Glass fiber
Aluminum
Explanation - 316 stainless steel resists oxygen transfer, maintaining anaerobic conditions.
Correct answer is: Stainless steel 316
Q.47 What property of polycarbonate makes it suitable for photobioreactor windows?
High electrical conductivity
High optical clarity and chemical resistance
High thermal expansion coefficient
Low cost
Explanation - Polycarbonate transmits visible light effectively while resisting solvents and microbial growth.
Correct answer is: High optical clarity and chemical resistance
Q.48 Which of the following materials is commonly used for disposable bioreactor culture flasks?
Polyethylene terephthalate (PET)
PVC
Glass
Aluminum
Explanation - PET is cheap, chemically inert, and can be sterilized before single use.
Correct answer is: Polyethylene terephthalate (PET)
Q.49 Which construction technique allows the integration of sensors directly into the walls of a bioreactor?
CNC machining with threaded ports
3D printing with embedded channels
Casting
Injection molding
Explanation - 3D printing can create built‑in channels for sensor leads while maintaining sterility.
Correct answer is: 3D printing with embedded channels
Q.50 Which material is NOT recommended for bioreactor construction in acidic media?
Stainless steel 304
PVC
Aluminum
Glass
Explanation - Aluminum corrodes quickly in acidic solutions, releasing ions into the medium.
Correct answer is: Aluminum
Q.51 What is the main advantage of using glass for the construction of a bioreactor that will be used for cell culture?
It is inexpensive
It is optically transparent and chemically inert
It has high thermal conductivity
It is mechanically weak
Explanation - Glass allows visual monitoring while not reacting with culture media.
Correct answer is: It is optically transparent and chemically inert
Q.52 Which of the following is a reason to choose stainless steel over aluminum for bioreactor construction?
Lower density
Better thermal conductivity
Higher corrosion resistance
Lower cost
Explanation - Stainless steel resists oxidation in many media, whereas aluminum can corrode.
Correct answer is: Higher corrosion resistance
Q.53 What is the primary benefit of using a disposable bioreactor bag made from PET?
It is biodegradable
It resists microbial adhesion
It is inexpensive and can be sterilized by UV
It is highly transparent to infrared
Explanation - PET is cheap and can be sterilized quickly with UV light, making it ideal for single‑use systems.
Correct answer is: It is inexpensive and can be sterilized by UV
Q.54 Which material is best suited for a bioreactor that requires frequent mechanical agitation?
PVC
Stainless steel 316
Glass
Polyethylene
Explanation - 316 stainless steel maintains structural integrity under constant agitation and is resistant to wear.
Correct answer is: Stainless steel 316
Q.55 Why is PVC commonly used for bioreactor tubing?
It is optically transparent
It is flexible and chemically inert
It can withstand high temperatures
It conducts electricity well
Explanation - PVC tubing can be sterilized and does not react with most culture media.
Correct answer is: It is flexible and chemically inert
Q.56 Which material would you choose for a disposable bioreactor that will be sterilized using gamma irradiation?
Glass
PVC
Polycarbonate
Polyethylene
Explanation - Polyethylene tolerates gamma radiation without significant degradation.
Correct answer is: Polyethylene
Q.57 What is a key advantage of using polycarbonate for a photobioreactor?
It is the cheapest material
It has high optical transmittance and good impact resistance
It is highly conductive
It is magnetic
Explanation - Polycarbonate provides clear windows while resisting cracks during operation.
Correct answer is: It has high optical transmittance and good impact resistance
Q.58 Which material is most appropriate for a bioreactor that needs to be sterilized by ethylene oxide?
Aluminum
PVC
Glass
PET
Explanation - PET can be sterilized with ethylene oxide without releasing harmful residues.
Correct answer is: PET
Q.59 What is the main reason for using stainless steel 304 in bioreactor construction?
It is cheaper than 316
It offers sufficient corrosion resistance in mild environments
It is lighter
It is transparent
Explanation - 304 is adequate for many processes and is less expensive than 316.
Correct answer is: It offers sufficient corrosion resistance in mild environments
Q.60 Which of the following properties is crucial for a bioreactor material that will be sterilized with autoclave?
Electrical conductivity
High melting point
High resistance to thermal shock
Low optical transparency
Explanation - The material must withstand rapid temperature changes without cracking during autoclaving.
Correct answer is: High resistance to thermal shock
Q.61 Which material is commonly used for constructing the internal surfaces of a disposable bioreactor to prevent fouling?
Silicone rubber
Glass
Aluminum
PVC
Explanation - Silicone has low surface energy, reducing biofilm formation and fouling.
Correct answer is: Silicone rubber
Q.62 Which construction material can be used for a bioreactor that will be operated at 100 °C?
PVC
Polypropylene
Stainless steel 316
Polyethylene
Explanation - 316 stainless steel can withstand temperatures above 100 °C without deforming.
Correct answer is: Stainless steel 316
Q.63 What is a disadvantage of using aluminum for a bioreactor that will be exposed to acidic media?
High cost
Poor mechanical strength
Rapid corrosion and ion release
Low optical transparency
Explanation - Aluminum reacts with acids, releasing ions that contaminate the culture.
Correct answer is: Rapid corrosion and ion release
Q.64 Which of the following materials is suitable for a disposable bioreactor bag that requires transparency to UV light?
PVC
Glass fiber
Polypropylene
Aluminum
Explanation - PVC transmits UV light and can be sterilized with UV radiation.
Correct answer is: PVC
Q.65 Which property of borosilicate glass makes it ideal for bioreactor construction?
Low density
High thermal expansion
Chemical resistance and low thermal expansion
Electrical conductivity
Explanation - Borosilicate glass resists chemical attack and withstands temperature changes without cracking.
Correct answer is: Chemical resistance and low thermal expansion
Q.66 Which material is commonly used for the construction of a disposable bioreactor vessel that needs to be sterilized by UV?
PVC
Glass
Aluminum
Polyethylene
Explanation - PVC can be sterilized by UV light due to its UV‑transmitting properties.
Correct answer is: PVC
Q.67 Which construction material can be used for a bioreactor that requires high optical clarity across the entire visible spectrum?
Polystyrene
Glass
PVC
Aluminum
Explanation - Glass offers uniform transparency across the visible spectrum, essential for optical sensors.
Correct answer is: Glass
Q.68 Which material is not suitable for a bioreactor that will be used in a highly saline environment?
Stainless steel 304
Aluminum
PVC
Glass
Explanation - Aluminum rapidly corrodes in saline solutions, leading to contamination.
Correct answer is: Aluminum
Q.69 What is a primary advantage of using polycarbonate for disposable bioreactor caps?
It is inexpensive
It can be autoclaved without deformation
It is optically transparent and chemically resistant
It conducts electricity
Explanation - Polycarbonate caps allow visual inspection while resisting solvents and sterilization processes.
Correct answer is: It is optically transparent and chemically resistant
Q.70 Which material would you choose for a disposable bioreactor bag that will be sterilized by steam autoclave?
Polyethylene
PVC
PET
Glass
Explanation - PET can withstand the high temperatures of autoclaving without deforming.
Correct answer is: PET
Q.71 Why is titanium often selected for impeller blades in bioreactors that handle harsh chemicals?
It is inexpensive
It has excellent corrosion resistance and high strength
It is magnetic
It is transparent
Explanation - Titanium can withstand aggressive chemicals without degradation, ensuring reliable operation.
Correct answer is: It has excellent corrosion resistance and high strength
Q.72 Which material is best suited for the construction of a bioreactor that will be used for anaerobic fermentation?
Stainless steel 316
PVC
Glass fiber
Aluminum
Explanation - 316 stainless steel resists oxygen ingress and is chemically inert for anaerobic processes.
Correct answer is: Stainless steel 316
Q.73 What is the main disadvantage of using PVC for a bioreactor that will be used at temperatures above 60 °C?
It melts and deforms
It is too expensive
It is not chemically resistant
It is not transparent
Explanation - PVC softens above 60 °C, compromising structural integrity.
Correct answer is: It melts and deforms
Q.74 Which material is most suitable for a disposable bioreactor that requires high chemical resistance to organic solvents?
Polypropylene
PVC
Glass
Aluminum
Explanation - Polypropylene resists many organic solvents, making it ideal for chemical‑intensive processes.
Correct answer is: Polypropylene
Q.75 What property of glass makes it suitable for monitoring a bioreactor through optical sensors?
Electrical insulation
Optical transparency and chemical inertness
High thermal conductivity
Magnetic properties
Explanation - Glass allows light to pass through without reacting with the culture medium.
Correct answer is: Optical transparency and chemical inertness
Q.76 Which of the following is a drawback of using aluminum for constructing a bioreactor vessel?
It has high electrical conductivity
It is prone to corrosion in acidic media
It is expensive
It is opaque
Explanation - Aluminum forms a fragile oxide layer that can break down in acids, releasing ions.
Correct answer is: It is prone to corrosion in acidic media
Q.77 Why would a bioreactor designer choose 316 stainless steel over 304 stainless steel?
Lower cost
Higher resistance to pitting corrosion in chloride environments
Higher transparency
Better thermal conductivity
Explanation - 316 contains molybdenum, which enhances chloride corrosion resistance compared to 304.
Correct answer is: Higher resistance to pitting corrosion in chloride environments
Q.78 Which material is commonly used for disposable bioreactor bags that need to be sterilized by UV?
PVC
Polycarbonate
Aluminum
Glass
Explanation - PVC can be sterilized with UV due to its transparency to ultraviolet wavelengths.
Correct answer is: PVC
Q.79 What is the benefit of using glass for the construction of a large bioreactor vessel?
It is inexpensive
It has high optical clarity and can be sterilized by autoclave
It is lightweight
It is magnetic
Explanation - Glass vessels allow visual monitoring and can withstand autoclaving temperatures.
Correct answer is: It has high optical clarity and can be sterilized by autoclave
Q.80 Which material would be most suitable for a disposable bioreactor that must be sterilized by gamma irradiation?
PVC
Polyethylene
Glass
Aluminum
Explanation - Polyethylene is tolerant to gamma radiation and does not degrade significantly.
Correct answer is: Polyethylene
Q.81 Which of the following is NOT a typical construction method for large bioreactors?
CNC machining
Casting
Injection molding
Extrusion
Explanation - Injection molding is generally used for small or disposable parts, not large bioreactors.
Correct answer is: Injection molding
Q.82 Which material is best suited for a bioreactor that requires optical monitoring and exposure to UV light?
PVC
Glass
Aluminum
Polyethylene
Explanation - Glass transmits UV light and is chemically inert, making it ideal for optical monitoring.
Correct answer is: Glass
Q.83 What property makes titanium suitable for constructing a bioreactor impeller that will be exposed to aggressive media?
High electrical conductivity
Excellent corrosion resistance and high strength
Low cost
High thermal expansion
Explanation - Titanium remains stable in harsh environments and is mechanically robust.
Correct answer is: Excellent corrosion resistance and high strength
Q.84 Which of the following materials is most suitable for a disposable bioreactor bag that needs to be sterilized by steam autoclave?
PET
PVC
Polypropylene
Glass
Explanation - Polypropylene can withstand the high temperatures of an autoclave without deforming.
Correct answer is: Polypropylene
Q.85 Which construction material is best for a bioreactor that must resist fouling and biofilm formation?
Silicone rubber
PVC
Glass
Aluminum
Explanation - Silicone has low surface energy, reducing microbial adhesion and fouling.
Correct answer is: Silicone rubber
Q.86 Which material is commonly used for the fabrication of disposable bioreactor culture flasks?
PET
PVC
Glass
Aluminum
Explanation - PET is cheap, chemically inert, and can be sterilized before single‑use.
Correct answer is: PET
Q.87 What is a major disadvantage of using PVC for a bioreactor that operates above 60 °C?
It will degrade and release contaminants
It is expensive
It is not chemically resistant
It is opaque
Explanation - PVC softens and can leach additives at high temperatures, contaminating the culture.
Correct answer is: It will degrade and release contaminants
Q.88 Which material is typically chosen for a bioreactor that will be used in a highly acidic environment?
Aluminum
Stainless steel 304
PVC
Glass
Explanation - 304 stainless steel has adequate resistance to many acidic media and is cost‑effective.
Correct answer is: Stainless steel 304
Q.89 What is the primary reason for using a glass‑fiber reinforced composite in bioreactor construction?
It is inexpensive
It provides high optical transparency
It offers high strength and chemical resistance
It is lightweight
Explanation - Glass‑fiber composites provide structural strength while resisting many chemicals.
Correct answer is: It offers high strength and chemical resistance
Q.90 Which of the following is NOT a typical material used for bioreactor tubing?
PEEK
PVC
Silicone
Aluminum
Explanation - Aluminum is rigid and corrodes in most media, making it unsuitable for flexible tubing.
Correct answer is: Aluminum
Q.91 Why is polycarbonate chosen for the construction of disposable bioreactor caps?
It is inexpensive
It can be sterilized by autoclave without deformation
It is optically transparent and chemically resistant
It conducts electricity
Explanation - Polycarbonate allows visual monitoring and resists many solvents, suitable for caps.
Correct answer is: It is optically transparent and chemically resistant
Q.92 Which material would you use for a disposable bioreactor bag that must be sterilized by gamma irradiation?
PET
PVC
Polypropylene
Glass
Explanation - Polypropylene can endure gamma radiation without significant degradation.
Correct answer is: Polypropylene
Q.93 What is a key advantage of using stainless steel 316 for bioreactor construction?
Lower cost than 304
Higher corrosion resistance in chloride environments
Better optical transparency
Higher thermal conductivity
Explanation - 316 stainless steel contains molybdenum, enhancing resistance to chloride‑induced pitting.
Correct answer is: Higher corrosion resistance in chloride environments
Q.94 Which material is best suited for a disposable bioreactor that will be sterilized by steam autoclave?
PVC
Polypropylene
PET
Glass
Explanation - Polypropylene can withstand autoclave temperatures without deforming.
Correct answer is: Polypropylene
Q.95 What is the main disadvantage of using aluminum for a bioreactor that will be exposed to acidic media?
It has high electrical conductivity
It is prone to corrosion and ion release
It is expensive
It is not optically transparent
Explanation - Acidic media attack aluminum, causing contamination of the culture.
Correct answer is: It is prone to corrosion and ion release
Q.96 Which of the following is a typical reason for selecting glass for a bioreactor that requires optical monitoring?
It is cheap
It is chemically inert and optically transparent
It is magnetic
It has high thermal conductivity
Explanation - Glass allows light to pass through while not reacting with the medium.
Correct answer is: It is chemically inert and optically transparent
Q.97 What is a key property of polypropylene that makes it suitable for disposable bioreactor flasks?
High electrical conductivity
Chemical resistance and heat stability
Optical clarity
Magnetic permeability
Explanation - Polypropylene resists many chemicals and can be sterilized by autoclave.
Correct answer is: Chemical resistance and heat stability
Q.98 Which material would be most suitable for a disposable bioreactor bag that needs to be sterilized by UV light?
PVC
Polycarbonate
Aluminum
Glass
Explanation - PVC transmits UV light and can be sterilized using UV radiation.
Correct answer is: PVC
Q.99 Which property of stainless steel makes it suitable for constructing bioreactor vessels that will be used in a high‑pH environment?
High electrical conductivity
Corrosion resistance in alkaline media
Low cost
Optical transparency
Explanation - Stainless steel resists corrosion from high pH solutions, maintaining vessel integrity.
Correct answer is: Corrosion resistance in alkaline media
Q.100 Why is borosilicate glass chosen for bioreactor vessels used in high‑temperature processes?
It is cheap
It has low thermal expansion and high chemical resistance
It is magnetic
It has high thermal conductivity
Explanation - Borosilicate glass can withstand rapid temperature changes without cracking.
Correct answer is: It has low thermal expansion and high chemical resistance
Q.101 Which material is best suited for a disposable bioreactor that requires chemical resistance to solvents and is sterilizable by UV?
PVC
Glass
Aluminum
Polypropylene
Explanation - PVC is chemically resistant, UV‑transparent, and can be sterilized by UV light.
Correct answer is: PVC
Q.102 What is a major advantage of using 316 stainless steel for a bioreactor that will be used in a chloride‑rich environment?
It is cheaper than 304
It offers superior pitting resistance
It is transparent
It conducts heat better
Explanation - 316’s molybdenum content prevents pitting corrosion in chloride solutions.
Correct answer is: It offers superior pitting resistance
Q.103 Which of the following materials is suitable for a disposable bioreactor that will be sterilized by gamma radiation?
PVC
Polyethylene
Glass
Aluminum
Explanation - Polyethylene is tolerant to gamma radiation and does not degrade significantly.
Correct answer is: Polyethylene
Q.104 What is the main drawback of using aluminum for a bioreactor that will be exposed to acidic solutions?
High cost
Poor mechanical strength
Rapid corrosion and ion release
Low optical transparency
Explanation - Acids attack aluminum, leading to contamination and material loss.
Correct answer is: Rapid corrosion and ion release
Q.105 Which material is most suitable for a bioreactor that requires optical monitoring in the visible spectrum?
Glass
PVC
Aluminum
Polyethylene
Explanation - Glass provides uniform transparency across the visible spectrum, essential for optical sensors.
Correct answer is: Glass
Q.106 What is the primary advantage of using 316 stainless steel over 304 for bioreactor construction?
Lower cost
Higher corrosion resistance to chlorides
Higher optical transparency
Better thermal conductivity
Explanation - 316 stainless steel contains molybdenum, enhancing resistance to chloride‑induced pitting.
Correct answer is: Higher corrosion resistance to chlorides
Q.107 Which construction material can be used for a disposable bioreactor that requires sterilization by steam autoclave?
PVC
Polypropylene
PET
Glass
Explanation - Polypropylene can withstand the high temperatures of an autoclave without deforming.
Correct answer is: Polypropylene
Q.108 What is a key disadvantage of using PVC for a bioreactor operating above 60 °C?
It softens and may leach additives
It is expensive
It is not chemically resistant
It is opaque
Explanation - PVC degrades at high temperatures, leading to contamination of the culture.
Correct answer is: It softens and may leach additives
Q.109 Which material is commonly used for the construction of disposable bioreactor bags that need to be sterilized by gamma irradiation?
PVC
Polyethylene
Glass
Aluminum
Explanation - Polyethylene withstands gamma radiation without significant degradation.
Correct answer is: Polyethylene
Q.110 What property of glass makes it suitable for a bioreactor that will be used in a high‑temperature environment?
It is cheap
It has low thermal expansion and high chemical resistance
It is magnetic
It has high thermal conductivity
Explanation - Glass can survive rapid temperature changes without cracking.
Correct answer is: It has low thermal expansion and high chemical resistance
Q.111 Why is polycarbonate chosen for the construction of disposable bioreactor caps?
It is inexpensive
It can be sterilized by autoclave without deformation
It is optically transparent and chemically resistant
It conducts electricity
Explanation - Polycarbonate allows visual inspection while resisting solvents.
Correct answer is: It is optically transparent and chemically resistant
Q.112 Which material would be most suitable for a disposable bioreactor that requires chemical resistance to organic solvents and is sterilizable by UV?
PVC
Glass
Aluminum
Polypropylene
Explanation - PVC resists many solvents and allows UV sterilization.
Correct answer is: PVC
Q.113 What is the main advantage of using titanium for a bioreactor impeller that will be exposed to aggressive media?
It is inexpensive
It has excellent corrosion resistance and high strength
It is magnetic
It is optically transparent
Explanation - Titanium remains stable in harsh media and is mechanically robust.
Correct answer is: It has excellent corrosion resistance and high strength
Q.114 Which material is most suitable for a disposable bioreactor that will be sterilized by steam autoclave?
PET
PVC
Polypropylene
Glass
Explanation - Polypropylene can endure autoclave temperatures without deformation.
Correct answer is: Polypropylene
Q.115 Why would a designer choose 316 stainless steel over 304 for a bioreactor exposed to chlorides?
It is cheaper
It offers superior pitting resistance
It is transparent
It has higher thermal conductivity
Explanation - 316’s molybdenum improves corrosion resistance in chloride‑rich environments.
Correct answer is: It offers superior pitting resistance
Q.116 Which of the following is NOT a typical construction method for large bioreactors?
CNC machining
Casting
Injection molding
Extrusion
Explanation - Injection molding is used for small or disposable parts, not large vessels.
Correct answer is: Injection molding
Q.117 Which material is best suited for a bioreactor that requires optical monitoring in the visible spectrum?
PVC
Glass
Aluminum
Polyethylene
Explanation - Glass offers clear visibility while not reacting with the culture medium.
Correct answer is: Glass
Q.118 What is the benefit of using glass for the construction of a large bioreactor vessel?
It is inexpensive
It can be sterilized by autoclave and offers optical clarity
It is lightweight
It is magnetic
Explanation - Glass vessels allow visual monitoring and survive autoclave temperatures.
Correct answer is: It can be sterilized by autoclave and offers optical clarity
Q.119 Which material would you choose for a disposable bioreactor bag that needs to be sterilized by gamma radiation?
PVC
PET
Polypropylene
Glass
Explanation - Polypropylene tolerates gamma radiation without significant degradation.
Correct answer is: Polypropylene
Q.120 What is the main advantage of using stainless steel 316 for bioreactor construction?
Lower cost than 304
Higher corrosion resistance in chloride environments
Better optical transparency
Higher thermal conductivity
Explanation - 316 stainless steel contains molybdenum, enhancing chloride corrosion resistance.
Correct answer is: Higher corrosion resistance in chloride environments
Q.121 Which of the following materials is suitable for a disposable bioreactor that will be sterilized by gamma irradiation?
PVC
Polyethylene
Glass
Aluminum
Explanation - Polyethylene can endure gamma radiation without significant degradation.
Correct answer is: Polyethylene
Q.122 Why is borosilicate glass often used in bioreactors that require high‑temperature operations?
It is cheap
It has low thermal expansion and high chemical resistance
It is magnetic
It conducts electricity
Explanation - Borosilicate glass tolerates rapid temperature changes without cracking.
Correct answer is: It has low thermal expansion and high chemical resistance
Q.123 Which material is commonly used for the construction of disposable bioreactor culture flasks?
PET
PVC
Glass
Aluminum
Explanation - PET is chemically inert, cheap, and can be sterilized before single use.
Correct answer is: PET
Q.124 Which of the following is a major drawback of using PVC for a bioreactor operating above 60 °C?
It will degrade and release contaminants
It is expensive
It is not chemically resistant
It is opaque
Explanation - PVC softens and may leach additives at high temperatures, contaminating the culture.
Correct answer is: It will degrade and release contaminants
Q.125 Which material is best suited for a disposable bioreactor that requires chemical resistance to organic solvents and is sterilizable by UV?
PVC
Glass
Aluminum
Polypropylene
Explanation - PVC resists many solvents and allows UV sterilization.
Correct answer is: PVC
Q.126 Why would a bioreactor designer choose 316 stainless steel over 304 for a chloride‑rich environment?
It is cheaper
It offers superior pitting resistance
It is transparent
It has better thermal conductivity
Explanation - 316 stainless steel’s molybdenum content reduces pitting corrosion in chloride solutions.
Correct answer is: It offers superior pitting resistance
Q.127 Which material would you use for a disposable bioreactor bag that needs to be sterilized by steam autoclave?
PVC
Polypropylene
PET
Glass
Explanation - Polypropylene can withstand autoclave temperatures without deforming.
Correct answer is: Polypropylene
Q.128 What is a major disadvantage of using aluminum for a bioreactor exposed to acidic media?
High cost
Poor mechanical strength
Rapid corrosion and ion release
Low optical transparency
Explanation - Aluminum corrodes in acids, leading to contamination and material loss.
Correct answer is: Rapid corrosion and ion release
Q.129 Which of the following materials is NOT typically used for bioreactor tubing?
PEEK
PVC
Silicone
Aluminum
Explanation - Aluminum is rigid and corrodes in most media, making it unsuitable for flexible tubing.
Correct answer is: Aluminum
Q.130 Why is polycarbonate chosen for the construction of disposable bioreactor caps?
It is inexpensive
It can be sterilized by autoclave without deformation
It is optically transparent and chemically resistant
It conducts electricity
Explanation - Polycarbonate allows visual inspection and resists many solvents.
Correct answer is: It is optically transparent and chemically resistant
Q.131 What is the primary advantage of using stainless steel 316 over 304 for bioreactor construction?
Lower cost
Higher corrosion resistance to chlorides
Better optical transparency
Higher thermal conductivity
Explanation - 316 stainless steel contains molybdenum, improving resistance to chloride‑induced pitting.
Correct answer is: Higher corrosion resistance to chlorides
Q.132 Which material is best suited for a disposable bioreactor that will be sterilized by gamma radiation?
PVC
PET
Polypropylene
Glass
Explanation - Polypropylene can tolerate gamma radiation without significant degradation.
Correct answer is: Polypropylene
Q.133 What property of glass makes it suitable for a bioreactor that will be used in a high‑temperature environment?
It is cheap
It has low thermal expansion and high chemical resistance
It is magnetic
It has high thermal conductivity
Explanation - Glass can survive rapid temperature changes without cracking.
Correct answer is: It has low thermal expansion and high chemical resistance
Q.134 Which material would be most suitable for a disposable bioreactor that requires chemical resistance to solvents and is sterilizable by UV?
PVC
Glass
Aluminum
Polypropylene
Explanation - PVC resists many solvents and allows UV sterilization.
Correct answer is: PVC
Q.135 Which material is commonly used for disposable bioreactor bags that need to be sterilized by gamma irradiation?
PVC
Polyethylene
Glass
Aluminum
Explanation - Polyethylene can tolerate gamma radiation without significant degradation.
Correct answer is: Polyethylene
Q.136 Why is titanium often selected for impeller blades in bioreactors that handle harsh chemicals?
It is inexpensive
It has excellent corrosion resistance and high strength
It is magnetic
It is optically transparent
Explanation - Titanium resists aggressive media and remains mechanically robust.
Correct answer is: It has excellent corrosion resistance and high strength
Q.137 Which material is best suited for a disposable bioreactor that will be sterilized by steam autoclave?
PET
PVC
Polypropylene
Glass
Explanation - Polypropylene can endure high temperatures of an autoclave without deforming.
Correct answer is: Polypropylene
Q.138 What is a major drawback of using aluminum for a bioreactor exposed to acidic solutions?
High cost
Poor mechanical strength
Rapid corrosion and ion release
Low optical transparency
Explanation - Acidic media attack aluminum, leading to contamination of the culture.
Correct answer is: Rapid corrosion and ion release
Q.139 Which of the following materials is NOT typically used for bioreactor tubing?
PEEK
PVC
Silicone
Aluminum
Explanation - Aluminum is rigid and corrodes, unsuitable for flexible tubing.
Correct answer is: Aluminum
Q.140 Which material is best suited for a bioreactor that requires optical monitoring in the visible spectrum?
PVC
Glass
Aluminum
Polyethylene
Explanation - Glass offers clear visibility while not reacting with the medium.
Correct answer is: Glass
Q.141 Why would a bioreactor designer choose 316 stainless steel over 304 for a chloride‑rich environment?
It is cheaper
It offers superior pitting resistance
It is transparent
It has better thermal conductivity
Explanation - 316’s molybdenum content reduces pitting corrosion in chloride solutions.
Correct answer is: It offers superior pitting resistance
Q.142 What is the main disadvantage of using PVC for a bioreactor that operates above 60 °C?
It degrades and leaches additives
It is expensive
It is not chemically resistant
It is opaque
Explanation - PVC softens and can release additives at high temperatures, contaminating the culture.
Correct answer is: It degrades and leaches additives
Q.143 Which material would you choose for a disposable bioreactor bag that needs to be sterilized by UV light?
PVC
Polycarbonate
Aluminum
Glass
Explanation - PVC transmits UV light and can be sterilized using UV radiation.
Correct answer is: PVC
Q.144 Which material is commonly used for the construction of disposable bioreactor culture flasks?
PET
PVC
Glass
Aluminum
Explanation - PET is cheap, chemically inert, and can be sterilized for single‑use.
Correct answer is: PET
Q.145 What is the main advantage of using stainless steel 316 for bioreactor construction?
Lower cost than 304
Higher corrosion resistance in chloride environments
Better optical transparency
Higher thermal conductivity
Explanation - 316 stainless steel’s molybdenum enhances chloride‑induced pitting resistance.
Correct answer is: Higher corrosion resistance in chloride environments
Q.146 Which of the following materials is suitable for a disposable bioreactor that will be sterilized by gamma irradiation?
PVC
Polyethylene
Glass
Aluminum
Explanation - Polyethylene can endure gamma radiation without significant degradation.
Correct answer is: Polyethylene
Q.147 Why is borosilicate glass often used in high‑temperature bioreactors?
It is cheap
It has low thermal expansion and high chemical resistance
It is magnetic
It conducts heat well
Explanation - Borosilicate glass tolerates rapid temperature changes without cracking.
Correct answer is: It has low thermal expansion and high chemical resistance
Q.148 What is a key disadvantage of using PVC in a bioreactor operating above 60 °C?
It degrades and leaches additives
It is expensive
It is not chemically resistant
It is opaque
Explanation - PVC softens at high temperatures, potentially contaminating the culture.
Correct answer is: It degrades and leaches additives
Q.149 Which material is commonly used for the construction of disposable bioreactor bags that need to be sterilized by gamma irradiation?
PVC
Polyethylene
Glass
Aluminum
Explanation - Polyethylene can tolerate gamma radiation without significant degradation.
Correct answer is: Polyethylene
Q.150 Which material is best suited for a disposable bioreactor that requires chemical resistance to organic solvents and is sterilizable by UV?
PVC
Glass
Aluminum
Polypropylene
Explanation - PVC resists many solvents and allows UV sterilization.
Correct answer is: PVC
Q.151 Which of the following is not a typical construction method for large bioreactors?
CNC machining
Casting
Injection molding
Extrusion
Explanation - Injection molding is used for small or disposable parts, not for large vessels.
Correct answer is: Injection molding
Q.152 What material is commonly used for the construction of disposable bioreactor flasks?
PET
PVC
Glass
Aluminum
Explanation - PET is cheap, chemically inert, and can be sterilized for single‑use.
Correct answer is: PET
Q.153 Which material is best suited for a disposable bioreactor that will be sterilized by steam autoclave?
PVC
Polypropylene
PET
Glass
Explanation - Polypropylene can endure autoclave temperatures without deforming.
Correct answer is: Polypropylene