Biology in Human Welfare MCQ Quiz in मल्याळम - Objective Question with Answer for Biology in Human Welfare - സൗജന്യ PDF ഡൗൺലോഡ് ചെയ്യുക

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.

The correct answer is Lipase

Concept:

• The cell wall is a crucial structure in many organisms, providing support and protection. Various enzymes can degrade the cell wall by breaking down its components.
• Different enzymes target specific components of the cell wall, such as proteins, polysaccharides, and other biopolymers.

Explanation:

• Lipase: Lipase is an enzyme that breaks down lipids (fats) into fatty acids and glycerol. It does not target cell wall components, hence does not cause degradation of the cell wall.
• Pectinase: Pectinase breaks down pectin, a polysaccharide found in the cell walls of plants, making it effective in degrading plant cell walls.
• Lysozyme: Lysozyme is an enzyme that degrades the peptidoglycan layer of bacterial cell walls, making it effective in breaking down bacterial cell walls.
• Chitinase: Chitinase breaks down chitin, a component of fungal cell walls, thus it is involved in the degradation of fungal cell walls.

The correct answer is Pectinases and proteases

Explanation:

 In the process of making jams and jellies, certain enzymes play crucial roles in ensuring the proper consistency and texture of the final product. The primary enzymes used are pectinases and proteases.

• Pectinases: These enzymes break down pectin, a type of polysaccharide found in the cell walls of fruits. Pectin contributes to the gelling process that is essential for the formation of jams and jellies. By partially breaking down pectin, pectinases help in achieving the desired gel consistency, improving the spreadability, and enhancing the extraction of juice from the fruit pulp.
• Proteases: While not as commonly used as pectinases in jam and jelly making, proteases might be utilized to break down any protein residues that could cloud the product or affect its texture. However, the primary role in achieving the desired consistency in jams and jellies is played by pectinases.

The other options listed do not play a significant role in the synthesis of jams and jellies:

• Streptokinases: These are enzymes used in medicine to break down blood clots and are not relevant to the food industry's process of making jams and jellies.
• Lipases: These enzymes break down fats and are not involved in the process of making jams and jellies, which primarily involves the modification of fruit pectin and sugars.
• Amylases: Amylases break down starches into sugars. While amylases might be used in some food processing applications to adjust sugar levels, they are not specifically utilized in the making of jams and jellies, which relies on the natural fruit sugars and added sweeteners.

Conclusion:

Enzymes used in the synthesis of jams and jellies are Pectinases and proteases

Key Points

• Gobar gas is a clean, non-polluted, and cheap source of energy.
• It is also known as biogas produced from cow dung.
• Gobar gas is produced through the anaerobic digestion of dung.
• In a closed, oxygen-free environment, bacteria decompose the organic matter to produce gas and organic soil products.
• It is an eco-friendly alternative source of energy to natural gas and other fossil fuels.
• It can improve off-grid people's access to renewable energy sources while assisting in the reduction of greenhouse gas emissions in rural locations.

Explanation:

• Gobar gas is an important factor for methane.
• It consists of 55−70% methane that is inflammable.
• The other chemical compositions of gobar gas include-
  • 25-50% CO₂
  • Residual amounts of N₂, H₂, and O₂
  • Traces of hydrogen sulfide (H₂S), water vapour (H₂O), and ammonia (NH₃).

Additional Information

• Ethane and Butane are the aliphatic hydrocarbons and components of natural gas.

Hence, the correct option is (3) Methane.

Concept:

• Methanogens are the bacteria which are responsible for the production of biogas.
• Biogas is a mixture of gases that is produced by the break down of organic matter like food scraps and animal waste, due to microbial activity.
• The microbial breakdown of cellulosic materials takes place in anaerobic conditions and the biogas is produced as a by-product.
• This biogas gas is used as a fuel for cooking and lighting.
• The biogas is produced during the secondary sewage treatment process.
• The biogas produced by using the cattle dung is also known as gobar gas.
• The biogas is produced in the biogas plant which consists of a tank made of concrete and 10-15  feet deep.
• In this tank the slurry of dung and also the bio wastes collected are fed into.
• A floating cover is also placed over it.
• This tank has an outlet for the gobar gas being produced which connects to the nearby households through a pipeline.
• The biogas or gobar gas is now used for different domestic purposes.

Explanation:

• The bacteria which grow anaerobically produce methane as a metabolic byproduct are known as Methanogens.
• These methanogens grow on the cellulosic material.
• Methanogens mostly produce Methane (CH4) and along with that some amount of carbon dioxide (CO2) and Hydrogen sulphide (H2S).
• This mixture of gases produced by the methanogens is known as Biogas.
• Therefore, Oxygen is not produced by the methanogens.

So the correct answer is Option (1).

The correct answer is A-III, B-I, C-IV, D-II

Explanation:

• Clostridium butylicum is known for producing butyric acid.
• Saccharomyces cerevisiae is commonly known as brewer's or baker's yeast and is associated with the production of ethanol through fermentation.
• Trichoderma polysporum is used in the production of Cyclosporin-A, an immunosuppressant drug.
• Streptococcus sp. is known for producing streptokinase, an enzyme used to dissolve blood clots.

The correct answer is Activated sludge

Explanation:

• The term "activated sludge" refers to a key component in the secondary stage of sewage treatment processes. This stage primarily involves biological processes for treating wastewater after the primary treatment has removed large solids and particulate matter. 
• Activated sludge is a muddy mass of microorganisms, mainly bacteria, mixed with air and wastewater in an aeration tank.
• This mixture forms flocs (aggregations of bacteria and particulates) which are very effective at digesting organic pollutants and nutrients present in the sewage.

Additional InformationThe sewage water generated everyday in cities and towns from the household, factories etc ,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 of the sewage involves the physical removal of the larger and smaller particles through filtration and sedimentation and then the effluent is then passed on to the large aeration tanks for the secondary treatment.
Secondary treatment-

• Here the effluent is constantly agitated mechanically which allows the growth of useful aerobic microbes into flocs.
• These microbes in the flocs consume major part of the organic matter in the effluent while growing.
• This effluent is passed 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.

Conclusion:

 In the sewage treatment, bacterial flocs are allowed to sediment in a settling tank. This sedimentis called as activated sludge

The correct answer is Vitamin B12

Explanation:-

• The conversion of milk to curd involves fermentation by lactic acid bacteria, primarily species like Lactobacillus bulgaricus and Streptococcus thermophilus. During this fermentation process, these bacteria produce various beneficial compounds, including vitamins.
• One such vitamin is Vitamin B₁₂, which is produced by certain strains of bacteria during fermentation.
• Vitamin B₁₂ is essential for various bodily functions, including the formation of red blood cells, neurological function, and DNA synthesis.
• Although milk itself contains Vitamin B₁₂, the concentration of this vitamin may increase during the conversion of milk to curd due to bacterial activity.

Additional InformationFermentation Process: The conversion of milk to curd involves the fermentation of lactose, the primary sugar in milk, by lactic acid bacteria such as Lactobacillus bulgaricus and Streptococcus thermophilus. These bacteria metabolize lactose to produce lactic acid, which acidifies the milk and causes it to curdle and thicken.

Bacterial Activity: During the fermentation process, lactic acid bacteria also produce various enzymes and other metabolites, including certain vitamins. One of the vitamins produced by some strains of bacteria, including certain lactobacilli, is Vitamin B₁₂ (cobalamin).

Vitamin B₁₂ Production: Vitamin B₁₂ is a complex molecule that cannot be synthesized by plants or animals but is produced by certain bacteria, archaea, and some fungi. In the case of curd fermentation, specific strains of bacteria may possess the ability to synthesize Vitamin B₁₂ as part of their metabolic processes. 

Increased Nutritional Value: As a result of bacterial activity during fermentation, the curd may contain higher levels of Vitamin B₁₂ compared to the original milk. This increase in Vitamin B₁₂ content enhances the nutritional value of curd, providing additional benefits to individuals consuming it.

Importance of Vitamin B₁₂: Vitamin B₁₂ is essential for various physiological functions in the human body, including the production of red blood cells, neurological function, and DNA synthesis. Adequate intake of Vitamin B₁₂ is necessary for overall health, and curd can serve as a dietary source of this important vitamin.

Overall, the conversion of milk to curd through fermentation by lactic acid bacteria can lead to an increase in the amount of Vitamin B₁₂ in the final product.

The correct answer is Cell to generate whole plant

Explanation:-

• Totipotency is the inherent capacity of a single cell, under appropriate conditions, to divide and differentiate into all the different types of cells necessary to generate a fully functional, complete organism.
• In plants, this means a single cell can give rise to a whole plant, including its roots, stems, leaves, and reproductive structures.
• In the plant kingdom, totipotency is a widely observed phenomenon. Almost every plant cell retains the genetic information needed to regenerate into a complete plant. This capability is exploited in horticulture and agriculture for cloning and propagating plants, as well as in scientific research for genetic studies.

Mechanism

• Cellular Dedifferentiation: The process begins with the dedifferentiation of a mature cell, which means it reverts back to a less specialized state. During this phase, the cell loses its mature characteristics and regains the capacity to proliferate.
• Cell Division and Proliferation: Once dedifferentiated, the cell undergoes rapid division, typically in a controlled environment such as a nutrient-rich culture medium. This phase results in the formation of a callus, an undifferentiated mass of cells.
• Redifferentiation: Under the influence of specific hormones and growth conditions, cells within the callus begin to differentiate into various types of cells needed to form different parts of the plant. This orchestration leads to the development of roots, shoots, and eventually a complete plant.

Conclusion:- The term 'totipotency' refers to the capacity of a cell to generate whole plant

Concept:

• Animal breeding aims at increasing the yield of animals and improving the desirable qualities of the produce.
• MOET technology has been demonstrated for cattle, sheep, rabbits, buffaloes, mares, etc.
• High milk-yielding breeds of females and high quality (lean meat with less lipid) meat-yielding bulls have been bred successfully to improve yields in a short time.

Important Points

• Multiple Ovulation Embryo Transfer Technology (MOET) is one such program of animal breeding.
• In this method, a cow is administered hormones with FSH-like activity to induce follicular maturation and superovulation.
• Superovulation refers to the maturation of 6-8 eggs, instead of just one, per cycle.
• The animal is either mated with an elite bull or artificially inseminated.
• The fertilized eggs at 8-32 celled stages are recovered non-surgically and transferred to surrogate mothers.
• This allows the genetic mother to be available for another round of superovulation.

Hence, the correct answer is option 3.