101. Streptokinase is obtained from
ⓐ. Streptococcus
ⓑ. Monascus purpureus
ⓒ. Trichoderma polysporum
ⓓ. Saccharomyces cerevisiae
Correct Answer: Streptococcus
Explanation: Streptokinase is produced by certain species of Streptococcus. It is a well-known example of a microbial product used directly in medicine. The source organism matters because different microbes produce very different useful substances. Knowing the source helps distinguish clot-busting agents from other microbial products.
102. Which microbial product is used as an immunosuppressant?
ⓐ. Streptokinase
ⓑ. Lipase
ⓒ. Pectinase
ⓓ. Cyclosporin A
Correct Answer: Cyclosporin A
Explanation: Cyclosporin A is a bioactive molecule that suppresses immune responses. This property is especially useful when controlling unwanted immune reactions, such as during organ transplantation. It is not a digestive enzyme or a clot-dissolving agent. Its significance lies in reducing the activity of the immune system when required.
103. Which microorganism produces cyclosporin A?
ⓐ. Penicillium notatum
ⓑ. Trichoderma polysporum
ⓒ. Aspergillus niger
ⓓ. Acetobacter aceti
Correct Answer: Trichoderma polysporum
Explanation: Trichoderma polysporum is the microbial source of cyclosporin A. This compound is valued for its immunosuppressive action rather than for food or industrial acid production. The organism-product match is important because Trichoderma is also a well-known microbial name in other biological applications. Here, its association is specifically with cyclosporin A.
104. What is the main medical use of statins produced by Monascus purpureus?
ⓐ. Dissolving blood clots
ⓑ. Clarifying fruit juices
ⓒ. Lowering blood cholesterol
ⓓ. Removing oily stains
Correct Answer: Lowering blood cholesterol
Explanation: Statins act by reducing the level of blood cholesterol. Because of this effect, they are widely recognized as medically useful microbial products. Their function is different from streptokinase, which acts on blood clots, and from industrial enzymes used in food processing. The key idea is regulation of cholesterol level in the body.
105. Statins are obtained from
ⓐ. Monascus purpureus
ⓑ. Streptococcus
ⓒ. Lactobacillus
ⓓ. Clostridium butylicum
Correct Answer: Monascus purpureus
Explanation: Monascus purpureus is the microbe associated with statin production. Statins are important because they help lower blood cholesterol. This makes them a major example of a beneficial microbial product used in medicine. The source must not be confused with microbes producing acids, antibiotics, or clot-busting agents.
106. Which pair is not correctly matched?
ⓐ. Lipase — detergent use
ⓑ. Streptokinase — clot buster
ⓒ. Cyclosporin A — immunosuppressant
ⓓ. Statin — dissolution of blood clot
Correct Answer: Statin — dissolution of blood clot
Explanation: Statins are linked with lowering blood cholesterol, not with dissolving blood clots. Clot dissolution is the role of streptokinase. The other pairs are correctly matched with their uses. The key distinction here is between cholesterol-lowering agents and clot-busting agents.
107. A detergent is specially designed to remove greasy food stains from fabric. Which microbial product would be most useful in such a detergent?
ⓐ. Lipase
ⓑ. Statin
ⓒ. Streptokinase
ⓓ. Cyclosporin A
Correct Answer: Lipase
Explanation: Greasy stains contain lipids, and lipases act on lipids. When added to detergents, these enzymes help break oily materials into simpler substances that can be washed away more easily. Their usefulness depends on substrate-specific enzyme action. That is why lipases are associated with cleaning fat-rich stains.
108. Which pair of microbial products is most directly associated with clarification of bottled fruit juices?
ⓐ. Streptokinase and statin
ⓑ. Pectinase and protease
ⓒ. Lipase and lactase
ⓓ. Cyclosporin A and penicillin
Correct Answer: Pectinase and protease
Explanation: Clarification of fruit juice requires removal of suspended materials that keep the liquid cloudy. Pectinases break down pectic substances, while proteases act on protein components that also contribute to turbidity. Together they improve clarity and appearance. Their role is therefore linked with processing quality rather than with medical treatment.
109. Which microbial product is correctly matched with its principal use?
ⓐ. Cyclosporin A — removal of oily stains
ⓑ. Streptokinase — lowering blood cholesterol
ⓒ. Statin — dissolving blood clots
ⓓ. Cyclosporin A — suppression of immune response
Correct Answer: Cyclosporin A — suppression of immune response
Explanation: Cyclosporin A is used as an immunosuppressant, especially where the immune response needs to be controlled. This function is different from that of streptokinase, which acts as a clot buster, and statins, which lower cholesterol. The distinction matters because all three are medically useful but serve different purposes. Correct matching depends on the specific physiological effect of each compound.
110. A physician wants a microbial product mainly to help reduce a patient's blood cholesterol level. Which source organism is most relevant?
ⓐ. Streptococcus
ⓑ. Monascus purpureus
ⓒ. Trichoderma polysporum
ⓓ. Penicillium notatum
Correct Answer: Monascus purpureus
Explanation: Monascus purpureus is associated with the production of statins. Statins help reduce blood cholesterol and are important in managing cardiovascular risk. This role is different from the clot-dissolving action of streptokinase and the immunosuppressive action of cyclosporin A. The organism is therefore identified through the medical use of its product.
111. Which statement correctly compares streptokinase and cyclosporin A?
ⓐ. Streptokinase helps dissolve clots, whereas cyclosporin A suppresses immune reactions.
ⓑ. Streptokinase lowers cholesterol, whereas cyclosporin A clarifies juices.
ⓒ. Streptokinase removes oil stains, whereas cyclosporin A forms curd.
ⓓ. Streptokinase acts as an antibiotic, whereas cyclosporin A produces ethanol.
Correct Answer: Streptokinase helps dissolve clots, whereas cyclosporin A suppresses immune reactions.
Explanation: Streptokinase and cyclosporin A are both valuable microbial products, but their uses are very different. Streptokinase is used where blood clot removal is needed, while cyclosporin A is used to reduce immune activity. Confusing them can lead to incorrect source-function matching. Their distinction is based on the body system each one affects.
112. A patient has a dangerous clot blocking blood flow in a vessel. Which microbial product is most directly useful in this situation?
ⓐ. Lipase
ⓑ. Streptokinase
ⓒ. Statin
ⓓ. Pectinase
Correct Answer: Streptokinase
Explanation: Streptokinase is called a clot buster because it helps dissolve blood clots. In a blocked vessel, restoring blood flow is the immediate need, and this is the use most closely linked with streptokinase. Lipases and pectinases are industrial enzymes, while statins mainly lower cholesterol over time. The urgent clinical purpose here points to clot removal.
113. The term single cell protein refers mainly to
ⓐ. a protein found only in animal muscle cells
ⓑ. a hormone secreted by microbial cells
ⓒ. microbial biomass used as a protein-rich food or feed source
ⓓ. a single enzyme purified from curd bacteria
Correct Answer: microbial biomass used as a protein-rich food or feed source
Explanation: Single cell protein means protein-rich microbial biomass used as a nutritional resource. The term does not refer to one purified protein molecule from a single cell. Instead, it points to the use of whole microbial mass as a source of nutrients. This shows another way microbes contribute to human welfare beyond fermentation and medicine.
114. Why are microbes considered suitable sources of single cell protein?
ⓐ. They grow very slowly and require large grazing fields.
ⓑ. They can produce useful biomass rapidly on a large scale.
ⓒ. They are used only when all plant proteins are absent.
ⓓ. They always contain chlorophyll and fix nitrogen.
Correct Answer: They can produce useful biomass rapidly on a large scale.
Explanation: Microbes multiply quickly and can generate large amounts of biomass in relatively short time. Because of this rapid growth, they can serve as efficient protein sources when cultured properly. Their usefulness lies in productivity and scalability rather than in the need for grazing land. This makes single cell protein an important application of microbial biomass.
115. Municipal wastewater carrying large amounts of organic matter and microbes is called
ⓐ. sludge
ⓑ. effluent
ⓒ. sewage
ⓓ. inoculum
Correct Answer: sewage
Explanation: Sewage refers to municipal wastewater that contains dissolved and suspended impurities. It usually carries a large organic load along with many microorganisms, including pathogens. Because of this composition, it cannot be discharged directly into natural water bodies without treatment. Its safe handling requires systematic processing.
116. Why is untreated sewage not suitable for direct release into rivers or lakes?
ⓐ. It contains high organic load and harmful microbes that can pollute water.
ⓑ. It lacks minerals needed for aquatic plants.
ⓒ. It contains only harmless gases and clean water.
ⓓ. It is too pure to support aquatic food chains.
Correct Answer: It contains high organic load and harmful microbes that can pollute water.
Explanation: Untreated sewage carries a large amount of organic matter and disease-causing microbes. When released directly, it degrades water quality and makes the water unsafe for use. The organic load also increases pollution stress in the receiving water body. This is why treatment is necessary before discharge.
117. Which statement best explains the need for sewage treatment plants?
ⓐ. They convert sewage directly into alcoholic beverages.
ⓑ. They remove only color from wastewater.
ⓒ. They are used only to store domestic water.
ⓓ. They reduce pollution load before wastewater is released.
Correct Answer: They reduce pollution load before wastewater is released.
Explanation: Sewage treatment plants are designed to make wastewater less polluting before it enters natural water bodies. They reduce organic matter, remove solids, and help lower the harmful microbial burden. This protects aquatic systems and improves sanitation. Their main purpose is pollution control, not storage or beverage production.
118. The pollution risk of sewage is mainly linked with its
ⓐ. low mineral content and high oxygen level
ⓑ. high organic load and presence of pathogens
ⓒ. bright color and high salt crystals
ⓓ. complete absence of microbes
Correct Answer: high organic load and presence of pathogens
Explanation: Sewage becomes dangerous mainly because it carries biodegradable organic matter and harmful microorganisms. The organic matter can overload natural waters, while pathogens create health risks. This combination makes untreated sewage environmentally and medically unsafe. Treatment aims to reduce both of these major problems.
119. Which stage of sewage treatment is mainly physical in nature?
ⓐ. Primary treatment
ⓑ. Secondary treatment
ⓒ. Anaerobic digestion
ⓓ. Activated sludge process
Correct Answer: Primary treatment
Explanation: Primary treatment mainly uses physical methods to remove floating and settleable materials. It does not depend chiefly on biological oxidation by microbial flocs. Filtration and sedimentation are the key operations at this stage. That is why it is described as a physical phase of treatment.
120. In primary sewage treatment, floating debris is removed mainly by
ⓐ. chlorination
ⓑ. anaerobic digestion
ⓒ. aeration
ⓓ. filtration
Correct Answer: filtration
Explanation: The first step in primary treatment commonly involves removing large floating materials by filtration. This prevents coarse debris from moving further into the treatment system. The process is mechanical and straightforward. It prepares the sewage for later settling steps.
