AIIMS AIPMT PMT Practice Questions – Microbes in Human Welfare

1. Which of the following is not an advantage of using biogas as fuel?
(a) It is cheaper than other fuels.
(b) It helps to clean environment.
(c) It is ideal for small scale application.
(d) It contains some other gases as impurities.
2. Select the mismatched pair out of the following.
13.Which of the following statements is incorrect regarding chemical fertilizers?
(a) They are easily soluble in water and are quickly absorbed by the plants.
(b) They can be applied to standing crop and are required in small quantities as compared to manures.
(c) They adversely affect the useful microbes present in the soil and their continuous use can cause destruction of soil.
(d) They improve physical properties of soil such as aeration, water holding capacity and humus content.
4. ____________produced by 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.
(a) Lipase
(b) Streptokinase
(c) Cyclosporin A
(d) Antibiotic streptomycin
5. Match different organisms in Column -1 with their uses in Column – II and select the correct answer from codes given below.
16. Which of the following antibiotics is not correctly matched with the source from which it is obtained?
17. Read the following statements and select the correct option.
Statement 1 : Biocontrol refers to the use of biological methods for controlling pathogens and pests.
Statement 2 : Use of biocontrol measures will greatly reduce our dependence on toxic chemicals and pesticides.
(a) Both statements 1 and 2 are correct and statement 2 is the correct explanation of statement 1.
(b) Both statements 1 and 2 are correct but statement 2 is not the correct explanation of statement 1.
(c) Statement 1 is correct and statement 2 is incorrect.
(d) Both statements 1 and 2 are incorrect.
8. The given figure represents a typical biogas plant. Select the correct option for A, B and C respectively.
biogas-plant(a) A is the inlet for cattle dung.
(b) C is the outlet for the release of biogas.
(c) B is the chamber which contains leftover slurry.
(d) All of these.
9. Select the correct statement(s) out of the following.
(a) Smoother crops are the crop plants that do not al low the weeds to grow nearby, e.g., Barley, Rye, Sorghum etc.
(b) Pyrethrum is an insecticide which is obtained from the inflorescence of Chrysanthemum cinerarifolium, C. coccineum etc.
(c) Frankia, a nitrogen fixing mycelial bacterium, is symbiotically associated with the root nodules of several non-legume plants like Casuarina and Alnus.
(d) All of these.
10. Study the following statements and select the correct ones.
(i) Methanogens are archaebacteria which produce methane in marshy areas.
(ii) Nostoc is a filamentous blue green alga which fixes atmospheric nitrogen.
(iii) Mycoplasma lack a cell wall and can survive without oxygen.
(a) (i) and (ii) (b) (i) and (iii)
(c) (ii) and (iii) (d) (i), (ii) and (iii)
11. Which of the following statements is not correct regarding mycorrhiza?
(a) It helps in absorption of phosphorus from the soil.
(b) It is a symbiotic association of fungi with the roots of higher plants.
(c) It helps the plant in developing resistance to root- borne pathogens.
(d) None of these
12. Read the given statements and select the correct option.
Statement 1 : Trichoderma is a free-living saprophytic fungus that commonly lives on dead organic matter in the soil and rhizosphere.
Statement 2 : The fungus is microscopic, conidia-producing member of Ascomycetes which is strongly antagonistic to other fungi.
(a) Both statements 1 and 2 are correct and statement 2 is the correct explanation of statement 1.
(b) Both statements 1 and 2 are correct but statement 2 is not the correct explanation of statement 1.
(c) Statement 1 is correct and statement 2 is incorrect.
(d) Both statements 1 and 2 are incorrect.
13. In which of the following steps large and small particles are removed from sewage through sequential filtration and sedimentation?
(a) Primary treatment
(b) Secondary treatment
(c) Biological treatment
(d) Tertiary treatment
14. Mark the correct option with respect to the composition of biogas.
(a) 50 – 70% H2 (b) 30 – 40% C02 (c) 95%CH„ (d) 10% CO
15. Biogas production is a
(a) three step microbial process
(b) three step physical process
(c) four step aerobic process
(d) four step anaerobic process.
16. Which of the following statements is incorrect with regard to pectinases?
(a) They are used in clearing of fruit juices.
(b) They are used in removing oily stains from laundry.
(c) They are commercially obtained from Byssochlamys fulvo.
(d) They are used in retting of fibres and preparation of green coffee.
17. Which of the following is a correct matching of a microbe and its industrial product?
(a) Mortierella renispora -Pectinase
(b) Aspergillus niger – Streptokinase
(c) Clostridium acetobutylicum – Butyric acid
(d) Lactobacillus bulgaricus-  Gluconic acid
18. Select the incorrect statement(s) out of the following.
(a) Secondary treatment of sewage is a physicochemical process.
(b) Azadirachtin is an insecticide obtained from the roots of Margosa.
(c) Free-living nitrogen fixers like Azospirillum and Azotobacter enrich the nitrogen content in soil.
(d) Both (a) and (b)
19. Given figure represents an overview of secondary sewage treatment process.
sewage-treatment-processSelect the incorrect statement regarding this.
(a) (i) can be the primary settling tank where heavy impurities (such as sand, small pebbles etc.) settle down.
(b) (ii) can be the secondary settling tank, in which activated sludge is produced and is used as an inoculum in aeration tanks.
(c) (ii) can be the aeration tank where a large number of aerobic heterotrophic microbes grow.
(d) (iii) can be the secondary settling tank where the bacterial floes are allowed to undergo sedimentation.
20. Secondary treatment of sewage
(a) removes grit and large pieces of organic matter
(b) involves shredding, churning, filtration and sedimentation
(c) does not require aeration
(d) involves microbial digestion of organic matter.
21. Match Column -1 with Column – II and select the correct option from the codes given below.
122. The inoculum is added to the fresh milk in order to convert milk into curd, the term ‘inoculum’ here refers to
(a) a starter rich in vitamin B,2
(b) a starter rich in proteins
(c) a starter containing millions of LAB
(d) an aerobic digester.
23. Which of the following options includes biofertilizers?
(a) Cowdung manure and farmyard waste
(b) A quick growing crop ploughed back into the field
(c) Nostoc, Oscillatoria
(d) All of these
24. Match Column -1 with Column – II and select the correct answer from the codes given below.
125. Which of the following sets contains only free living Infixing bacteria?
(a) Anabaena, Aulosira, Nostoc
(b) Frankia, Azotobacter, Rhizobium
(c) Rhizobium, Frankia, Beijerinckia
(d) Azotobacter, Beijerinckia, Klebsiella
26. Which out of the following is a N2-fixing blue green alga?
(a) Anabaena (b) Frankia
(c) Rhizobium (d) Azotobacter
27. Identify the blank spaces A, B, C and D in the following table and select the correct answer.
128. Which of the following is not an example of weed-control by the use of bio-herbicides?
(a) Phytophthora palmivora controls the growth of milk weed vines in citrus orchards.
(b) Extensive growth of cacti in India and Australia is controlled by the introduction of its natural herbivore cochineal insect (Cactoblastic cactorum).
(c) Control of Eichhornea crassipes in Florida (U.S.A) with the application of an indigenous fungus Cercospora rodmanii.
(d) Control of aphids by the use of ladybird bettles.
29. Study the given flowchart representing three different stages of sewage treatment.
Read the following statements regarding this and select the incorrect ones.
(i) A is the sewage treatment process which causes the physical removal of 20-30% of organic materials present in sewage in particulate form; this particulate material is removed by screening, settling etc.
(ii) B is the sewage treatment process during which significant reduction in BOD of the effluent takes place.
(iii) C is the biological sewage treatment process which involves the use of aerobic micro-organisms and formation of activated sludge.
(iv) Sewage treatment processes A and C are purely biological whereas the process B is mechanical or chemical.
(a) (i)and(ii) (b) (i) and (iii)
(c) (ii) and (iii) (d) (iii) and (iv)
sewage-treatment-flowcart30. Identify the blank spaces A, B, C and D in the table given below and select the correct answer.
1(a) A-Trichoderma polysporum; B – As an immunosuppressive agent; C – Yeast (Fungus);
D – Lowering of blood cholesterol
(b) A – Trichoderma polysporum; B-Lowering of blood cholesterol; C – Yeast (Fungus); D – As an immunosuppressive agent
(c) A – Yeast (Fungus); B-Lowering of blood cholesterol; C – Trichoderma polysporum; D – As an immunosuppressive agent
(d) A – Streptococcus; B-As an immunosuppressive agent; C – Bacterium; D – Lowering of blood cholesterol
31. Read the following steps concerning primary sewage treatment.
(i) Sewage is allowed to pass into a sedimentation tank where most of the suspended material settles down.
(ii) Sewage is passed through a series of filters to remove large floating objects like polythene bags.
(iii) The concentrated solid material that settles down forms the primary sludge.
(iv) Filtered sewage is passed through the grit chamber where coarse solid materials (small pebbles etc.) settle down by gravity.
Arrange these steps in the right sequence and select the correct option.
(a) (i) —> (ii) —>(iv) -»(iii)
(b) (ii) —> (iv)—> (i) —> (iii)
(c) (ii)—> (i)—> (iii) —> (iv)
(d) (iv)—> (iii)—> (ii)—>(i)
32. Given table summarizes the differences between primary sludge and activated sludge. Pick up the wrong pair of differences and select the correct option.
1(a) 1 and 2 (b) 2 and 3
(c) 1,2 and 3 (d) 1 and 4
33. Read the following statements.
(i) __________are the antibiotics which can kill or destroy a number of pathogens that belong to different groups with different structure and wall composition.
(ii) Antibiotic bacitracin is obtained from__________.
(iii) Enzyme__________has fibrinolytic effect, it helps in
clearing blood clots inside the blood vessels.
(iv) __________is an eleven membered cyclic oligopeptide
obtained through fermentative activity of fungus Trichoderma polysporum.
(a) (i) Specific antibiotics
(ii) Streptomyces noursei
(b) (ii) Bacillus licheniformis
(iii) Streptokinase
(c) (i) Broad spectrum antibiotics
(iii) Cyclosporin A
(d) (ii) Bacillus licheniformis
(iv) Statin
34. Read the following statements (i – v) with certain mistakes in two of them.
(i) Association of VAM with crop plants helps in conversion of less productive field into more productive field.
(ii) Dough, which is used for making foods such as dosa and idli is fermented by fungi and algae.
(Hi) Toddy, a traditional drink of southern India is made by fermentation of sap of palms.
(iv) Large holes in ‘Swiss cheese’ are due to production of large amount of methane by Propionibacterium sharmanii.
(v) In our stomach, lactic acid bacteria play a beneficial role in checking disease – causing mircobes.
Which are the two statements having mistakes?
(a) (i) and (iii) (b) (ii)and(iv)
(c) (ii), (iii) and (iv) (d) (iii), (iv) and (v)
35. Consider the following four statements (i-iv) related to organic farming and select the correct option stating which ones are true (T) and which ones are false (F).
(i) Produces food crops rich in lipids, vitamins and iron
(ii) Uses biofertilizers which increase soil fertility
(iii) Involve more use of chemical fertilizers and pesticides
(iv) Raising crops through the use of bacteria, mycorrhizae and cyanobacteria
136. Given flowchart shows different stages of biogas production. Select the correct statements regarding this.
1(i) ‘P’ represents the process of solubilisation during which the decomposer microbes cause the breakdown of complex organic substances into simple soluble substances by secreting hydrolytic enzymes.
(ii) ‘Q’ represents the process of methanogenesis during which methanogenic bacteria become active and produce biogas.
(iii) ‘R’ represents the process of solubilisation by which aerobic heterotrophic microbes cause decomposition of organic wastes.
(iv) ‘Q’ represents the process of acidogenesis by which monomers are changed into organic acids (mainly acetic acid) with the help of fermentative microbes.
(v) Chemical equation for the process ‘R’ can be shown as:
137. Select the incorrect combination of antibiotic, its source and action.
138. Read the following statements.
(i) Microbes such as Lactobacillus, commonly called Lactic Acid Bacteria (LAB) grow in milk and convert milk into curd, yoghurt, cheese, etc; These improve the nutritional quality by increasing_______.
(ii) Dough which is used for making bread is fermented by.__________•
(iii) Methanogens e.g., Methanobacterium grow __________ on cellulosic material, produce large amount of methane along with C02 and H2.
(iv) __________ is the process of removal of small and large, floating and suspended solids from sewage through the processes of filtration and sedimentation. Select the correct fill-ups for above statements.
(a) (i) Vitamin B12
(iii) Anaerobically
(b) (ii) Saccharomyces cerevisiae
(iv) Secondary treatment
(c) (i) Vitamin A
(ii) Saccharomyces cerevisiae
(d) (iii) Aerobically
(iv) Primary treatment
39. Read the given statements and select the correct option. Statement 1: Organic farming is the form of agriculture that relies on techniques such as crop rotation, green manure, compost and biological pest control to maintain soil productivity and control pests on a farm.
Statement 2: Organic farming limits the use of artificial fertilizers, pesticides (which include herbicides, insecticides and fungicides), food additives and genetically modified organisms.
(a) Both statements 1 and 2 are correct and statement 2 is the correct explanation of statement 1.
(b) Both statements 1 and 2 are correct but statement 2 is not the correct explanation of statement 1.
(c) Statement 1 is correct and statement 2 is incorrect.
(d) Both statements 1 and 2 are incorrect.
40. Select the correct statements.
(a) Azolla is an aquatic fern which propagates vegetatively and spreads in rice fields rapidly.
(b) Filaments of Anabaena possess heterocysts and multiply inside the air spaces of dorsal lobe of leaves of Azolla.
(c) The effluent and residue left after the fermentative generation of biogas is rich in minerals, lignin and a part of cellulose, which serves as an ideal manure.
(d) All of these.
1

Related Posts
Leave a reply
Captcha Click on image to update the captcha .