Biology in Human Welfare MCQ Quiz - Objective Question with Answer for Biology in Human Welfare - Download Free PDF

The correct answer is A and C only

Explanation:

• Household products such as bread, curd, alcoholic beverages, and other fermented items are often prepared using specific microbes. These microbes play a vital role in enhancing the quality, flavor, and nutritional value of these products.
• Some microbes are industrially used for other purposes, such as the production of antibiotics or enzymes, but they are not involved in the preparation of common household products.
  • A) Aspergillus niger: This fungus is commonly used for the industrial production of citric acid and enzymes but is not involved in the preparation of household products.
  • B) Lactobacillus: This bacterium is involved in the preparation of household products like curd and yogurt. It helps in the fermentation of milk, converting lactose into lactic acid.
  • C) Trichoderma polysporum: This fungus is used industrially for the production of cyclosporin, an immunosuppressive drug. It is not involved in the preparation of household products.
  • D) Saccharomyces cerevisiae: Commonly known as baker's yeast, this microbe is widely used in the preparation of bread and alcoholic beverages like beer and wine. It plays a crucial role in fermentation, producing carbon dioxide and ethanol.
  • E) Propionibacterium shermanii: The large holes in ‘Swiss cheese’ are due to the production of a large amount of CO₂ by a bacterium named Propionibacterium sharmanii.

The correct answer is D only

Concept:

• Nitrogen fixation is the process by which atmospheric nitrogen (N₂) is converted into a form that plants can absorb and utilize, such as ammonia (NH₃).
• This process is carried out by certain microorganisms, including free-living and symbiotic bacteria, as well as some cyanobacteria. These organisms possess an enzyme called nitrogenase, which catalyzes the nitrogen fixation process.
• Not all organisms have the ability to fix nitrogen. Some organisms, despite being photosynthetic or aquatic, lack the enzyme nitrogenase and therefore cannot participate in nitrogen fixation.

Explanation:

• Bacteria can fix atmospheric nitrogen while free-living in the soil (examples Azospirillum and Azotobacter), thus enriching the nitrogen content of the soil.
• Cyanobacteria are autotrophic microbes widely distributed in aquatic and terrestrial environments many of which can fix atmospheric nitrogen, e.g. Anabaena, Nostoc, Oscillatoria, etc.
• Volvox (Option D): Volvox is a green algae that forms colonies and is photosynthetic. It does not have the enzyme nitrogenase and lacks the capability to fix atmospheric nitrogen.Volvox depends on already available forms of nitrogen in its environment for its nutritional needs.

The correct answer is Removing clots from blood vessels

Explanation:

Streptokinase produced by the bacterium Streptococcus and modified by genetic engineering is used as a ‘clot buster’ for removing clots from the blood vessels of patients who have undergone myocardial infarction leading to heart attack.

• Streptokinase is used to remove the blood clots that are formed in the blood vessels i.e acts like a clot buster.
• It is mainly used for people who have undergone myocardial infarction leading to heart attack.
• This helps in restoring the blood flow to the affected tissue.

Other Options:

• Curd production: Curd production involves the activity of lactic acid bacteria like Lactobacillus. The fermentation of lactose into lactic acid by these bacteria gives curd its texture and tangy taste.
• Ethanol production: Ethanol is produced by the fermentation of sugars by yeast, particularly Saccharomyces cerevisiae. 
• Liver disease treatment: This is incorrect. Streptokinase is not used for treating liver diseases. Treatments for liver conditions typically include medications like antivirals, immunosuppressants, or lifestyle changes, depending on the condition (e.g., hepatitis, cirrhosis). 

The correct answer is Beer

Explanation:

• Alcoholic beverages are classified into two main categories: distilled and non-distilled beverages.
• Depending on the type of raw material used for fermentation and the type of processing (with or without distillation) different types of alcoholic drinks are obtained.
• Wine and beer are produced without distillation whereas whisky, brandy and rum are produced by distillation of the fermented broth.
• Distillation is a crucial process in the production of certain types of alcoholic beverages such as whisky, brandy, and rum. Distillation helps to separate alcohol from the fermented broth, increasing its concentration.
• Non-distilled alcoholic beverages are produced through fermentation, a process in which yeast converts sugars into alcohol and carbon dioxide.
• Beer is an example of a non-distilled alcoholic beverage, as it is produced by the fermentation of malted barley and other grains using yeast.

The correct answer is A. Idli, B. Dosa, C. Toddy, D. Cheese.

Explanation:

Fermentation is a metabolic process where microbes convert carbohydrates into alcohol, gases, or acids. This process is widely used in the production of various food items to enhance flavor, texture, and preservation.

• A. Idli:
  • Idli is a traditional Indian food made from fermented rice and urad dal (black gram).
  • The fermentation process involves the growth of lactic acid bacteria, which helps in batter rising and imparts a tangy flavor.
• B. Dosa:
  • Dosa is another popular Indian dish prepared using a fermented batter of rice and urad dal.
  • Similar to idli, the fermentation by lactic acid bacteria ensures a smooth texture and tangy taste.
• C. Toddy:
  • Toddy is an alcoholic beverage made from the fermented sap of palm trees or coconut trees.
  • The fermentation process is carried out by natural yeasts present in the sap, converting sugars into alcohol.
• D. Cheese:
  • Cheese is produced from milk through curdling and fermentation.
  • The fermentation process involves various bacteria and molds, which impart unique flavors and textures to different types of cheese.

The correct answer is Fermentation.

Key Points

• Fermentation is a metabolic process that produces chemical changes in organic substrates through the action of enzymes.
• In biochemistry, it is narrowly defined as the extraction of energy from carbohydrates in the absence of oxygen​

Additional Information 

• Pasteurization  is a process in which packaged and non-packaged foods are treated with mild heat.
• Condensation is the process where water vapor becomes liquid. It is the reverse of evaporation, where liquid water becomes a vapor
• Steaming is a method of cooking using steam. 

Key Points

• Fumigation is a method of pest control that involves totally saturating a space with gaseous insecticides or fumigants in order to poison any pests present.
• A chemical that exists in a gaseous state at a sufficient temperature and pressure and is concentrated enough to be fatal to pest organisms is called a fumigant.
• The area is sealed after the fumigation process and the entry of humans is banned for a certain period of time.
• There are three types of fumigation, these are gas fumigation, liquid fumigation, and solid fumigation.
• Fumigants are hazardous to the environment and health.
• Fumigation is performed in many laboratories or factories at a very large scale where biosafety is a major concern.
• The optimum temperature range for fumigation is 60 ºF to 80 °F.
• The total volume of the area being treated determines the fumigant dose, not the number of commodities present.

Explanation:

• Formaldehyde is a chemical agent used for fumigation.
• Formaldehyde fumigation has long been a recognized technique for areas where microbiological cleanliness is required.
• It kills vegetative spores, bacteria, nematodes, insects, rodents, etc.
• Formalin kills the microbes by alkylating the amino acids and sulfhydryl group of proteins and purine base s.
• It is also utilized for the control of pests in grain-stored buildings.
• Formaldehyde is toxic to most living being, including humans.
• It causes eye irritation, and breathing problems, and hazardous residues cause allergies, etc.
• some products are corrosive or flammable. 

Hence, the correct option is (1) formaldehyde.

The correct answer is Plastic.

Key Points

• Plastic is non-biodegradable.
• Plastics are synthetic polymers and are derived from the by-products of petroleum.
• The monomers derived from petroleum are combined together (polymerization) to make plastic.
• These polymeric substances cannot be digested or decomposed by any micro-organism and hence plastics are non-biodegradable.

Additional Information  Non-biodegradable

• A Non-Biodegradable material can be defined as a kind of substance which cannot be broken down by natural organisms and acts as a source of pollution.
• hey remain on earth for thousands of years without any degradation. Hence, the threat caused by them is also more critical. 

Biodegradable

• A biodegradable material can be defined as a material which can be decomposed by bacteria or other natural organisms and not be added to pollution.
• Biodegradable wastes are such waste materials which are and can be degraded by natural factors like microbes (e.g. bacteria, fungi and a few more), and abiotic elements like temperature, UV, oxygen, etc.
• Some examples of such wastes are food materials, kitchen wastes, and other natural wastes

The Correct answer is Option 3

Key Points

• The Red Blood Cells (RBCs) of a person with blood group 'O' contain neither A nor B agglutinogens.

• Agglutinogens (also called antigens) are proteins found on the surface of red blood cells that determine blood type.

• In the O blood group, there are no agglutinogens (A or B) present on the surface of the RBCs.
• Instead, individuals with blood type O have anti-A and anti-B antibodies in their plasma, which will react against blood cells with A or B antigens if introduced.
• Hence, the correct answer is Neither A nor B.

Concept-

• Plant breeding is the purposeful manipulation of plant species in order to create desired plant types that are better suited for cultivation, give better yields, and are disease resistant.
• Conventional plant breeding has been practised for thousands of years, since the beginning of human civilization, recorded evidence of plant breeding dates back to 9,000-11,000 years ago.
• Many present-day crops are the result of domestication in ancient times.
• Today, all our major food crops are derived from domesticated varieties.
• Classical plant breeding involves crossing or hybridization of pure lines, followed by artificial selection to produce plants with desirable traits of higher yield, nutrition, and resistance to diseases.

Explanation-

• Resistance to leaf and stripe rust, hill bunt in wheat was transferred and resulted in a new variety called Himgiri.
• Resistance to Chilly mosaic virus, Tobacco mosaic virus, and Leaf curl in chilli was transferred and resulted in a new variety called Pusa Sadabahar.
• Resistance to Black rot and Curl blight black rot in cauliflower was transferred and resulted in a new variety called Pusa shubhra.
• Better-yielding semidwarf rice varieties Jaya and Ratna were developed in India.

Additional Information

• Resistance to the yellow mosaic virus in bhindi (Abelmoschus esculentus) was transferred from a wild species and resulted in a new variety of A. esculentus called Parbhani Kranti.

Concept:

• Plant breeding is the intentional manipulation of plant species to create desirable varieties that are better suited for cultivation, can give better yield and are disease resistant.
• Several bacterial, fungal or viral pathogens affect the crop plants, reducing their yield.
• Crop losses can sum up to 20-30% or even total loss.
• Thus, development of disease-resistant cultivars are essential to enhance food production.
• Resistance of host plant refers to the ability of the plant to prevent the infection and this is determined by the genetic constituent of the plant.
• Study of the pathogen and its mode of transmission precedes the breeding process.

Important Points

• Breeding can be achieved by conventional methods or mutation breeding.
• The steps for breeding are:
  1. Screening germplasm for resistance sources
  2. Hybridization of selected parents
  3. Selection and evaluation of the hybrids
  4. Testing and release of new varieties

Resistant Varieties Against Insect Pests - 

• From the above table we can conclude that Pusa Gaurav is a variety of Rape seed mustard.

Hence, the correct answer is option 1.

Concept:

• Sewage is the large quantities of waste water generated everyday in cities and towns from the household, factories etc and Human excreta forms the major component of this waste water .
• As this sewage water contains a large amounts of organic matter and microbes, therefore it is treated in the Sewage treatment plants (STPs) before releasing it into waterbodies.
• This treatment is carried out in two stages-
  • Primary treatment
  • Secondary treatment

Primary treatment-

• Primary treatment of the sewage involves the physical removal of the larger and smaller particles through filtration and sedimentation.
• The effluent is then passed on to the large aeration tanks for the secondary treatment.

Secondary treatment-

• The reduction in the  BOD of the sewage water mainly takes place during the secondary treatment process.
• Here the effluent is constantly agitated mechanically which allows the growth of useful aerobic microbes into flocs.
• Flocs are the masses of bacterial associated with fungal filaments to form mesh like structures.
• These microbes in the flocs consume major part of the organic matter in the effluent while growing.
• This effluent is passed o to the settling tank where the bacterial flocs are allowed to sediment and this sediment is called activated sludge.
• A little amount of activated sludge is added back into the aeration tank and it acts as a inoculum.
• The remaining sludge is passed on to the large tanks called Anaerobic sludge digesters, where other bacteria grow anaerobically and digest the bacteria and fungi in the sludge.
• During this process of digestion biogas is produced.
• The effluent produced is released into the water bodies and the solid sludge remained is taken for further processing.
• The processed solid sludge then can be used as fertilizers and manures in the fields.

Explanation:

• Dissolved oxygen is the amount of oxygen that is present in water and is available to the living organisms in the water.
• Biological oxygen demand (BOD) is the amount of dissolved oxygen needed by the aerobic organisms to break down the organic matter present in the water sample.
• Therefore, BOD test measures the rate of uptake of oxygen by microorganisms in a sample of water.
• This means that the greater the BOD of the waste water, the more polluted it is.
• The sewage water should be treated until this BOD is reduced.

The correct answer is Option (4).

The correct answer is Streptokinase

Explanation:

• Cyclosporin: This is an immunosuppressive drug that is primarily used to prevent organ transplant rejection and to treat certain autoimmune conditions. Cyclosporin A is produced by the fungus Trichoderma polysporum. 
• Pectinase: This enzyme breaks down pectin, a polysaccharide found in plant cell walls. It is commonly used in the food industry, particularly in fruit juice production
• Streptokinase: This is an enzyme produced by certain strains of Streptococci bacteria. It is used as a thrombolytic medication to dissolve blood clots in patients who have suffered from conditions like myocardial infarction, pulmonary embolism, and stroke. Streptokinase works by converting plasminogen to plasmin, which then breaks down fibrin, the main protein component of blood clots.
• Protease: This is a general term for enzymes that break down proteins.

Concept:

• Several bacterial, fungal or viral pathogens affect the crop plants, reducing their yield.
• Crop losses can sum up to 20-30% or even total loss.
• Thus, development of disease-resistant cultivars are essential to enhance food production.
• Resistance of host plant refers to the ability of the plant to prevent the infection and this is determined by the genetic constituent of the plant.

Important Points

• The resistance of the host crop plant can be achieved by different types of characteristics:
  • Morphological - Resistance is achieved due to some morphological features.
  • Biochemical - The pest resistance is achieved by some biochemical agents.
  • Physiological - The host plant prevents pest infection by physiological processes.

Corrected Table:

Therefore, the correct answer is (a - ii), (b - iv), (c - i), (d - iii).

Concept:

• Plant breeding along with animal breeding is the means by which the food production can be increased.
• Plant breeding involves the manipulation of existing varieties of the crop to obtain superior varieties with desired characteristics.
• The desired plant types are better suited for cultivation, give better yield, and are disease resistant.
• The main steps involved in plant breeding are:
  • Collection of variability.
  • Evaluation and selection of parents.
  • Cross-hybridization among the selected parents.
  • Selection and testing of superior recombinants.
  • Testing, release and commercialization of new cultivars.

Explanation:

Steps of Plant Breeding - 

1. Collection of variability - 
   • Genetic variability is the basis of any breeding program.
   • In several instances, pre-existing genetic variability is found in wild varieties of the crop.
   • Collection and preservation of such wild varieties are thus essential for a successful breeding program to take place.
2. Evaluation and selection of parents - 
   • Plants with desirable characteristics are selected.
3. Cross-hybridization among the selected parents - 
   • Many times the desired characteristics might be present in different plant species that need to be combined.
   • In such cases, cross-hybridization among the selected parents is carried out to obtain a hybrid with desired characters.
4. Selection and testing of superior recombinants - 
   • This step in plant breeding involves the selection of the progeny of hybrids with desired characteristics.
   • The hybrid selected would be superior to both parents.
5. Testing, release, and commercialization of new cultivars - 
   • The selected lines of hybrids are evaluated for their traits.

• The genetic variability in the germplasm collection is the most crucial part of plant breeding.
• Therefore, the biggest constraint of plant breeding is the availability of desirable genes in the crop and its wild relatives.

So the correct answer is option 1.

Additional Information

• The availability of disease-resistant genes in crop varieties is a limitation only for conventional breeding method.
• Other methods of breeding like mutation breeding, genetic engineering and selection of somaclonal variants may help in selection of the desired genes.