BIOLOGY Case study (4 Marks)

Microorganisms include bacteria, viruses, fungi and protozoa. In our mind, we presume, most of the time, that microbes are always harmful. Microbes are, of course, the causal agents of many infections diseases of plants and animals including humans but they also have lots of beneficial role. Lactic acid bacteria (LAB) are one of this kind of useful group. These are Gram positive, non-sporulating, either rod-shaped or spherical bacteria. They produce lactic acid in milk products as major metabolic end product of carbohydrate fermentation. LAB are considered as natural fermentors. Lactobacillus is a common LAB which converts lactose sugar of milk into lactic acid, that causes coagulation and partial digestion of milk protein casein. Milk is then changed into curd, yoghurt and cheese. Lactobacillus is also used in probiotics which have potentially beneficial effect on gut ecosystem of humans. Some other probiotic strain used belong to the Genus Bifidobacterium.

1. Which of the following is not considered as microorganisms?

1. Bacteriophage.
2. Streptococcus.
3. Porphyra.
4. Staphylococcus.

2. Select the incorrect option regarding the characteristics of lactic acid bacteria.

1. They are rod-shaped or spherical.
2. They are Gram positive.
3. They take part in carbohydrate fermentation.
4. They are acid intolerant.

3. Which of the following is not a lactic acid producing bacteria?

1. Streptococcus.
2. Lactococcus.
3. Saccharomyces.
4. Enterococcus.

4. Probiotics are:

1. Gut friendly live bacteria.
2. Acid balancing alternated bacteria.
3. Beneficial amount of dead bacteria.
4. Gram negative attenuated bacteria.

5. Assertion: Lactobacillus bacteria do not retain crystal violet stain while staining.

Reason: Lactobacillus have a very thin layer of peptidoglycan layer in their cell wall.

1. Both assertion and reason are true and reason is the correct explanation of assertion.
2. Both assertion and reason are true but reason is not the correct explanation of assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Read the following and answer any four questions from (i) to (v) given below:
Enzymes are best known for their ability to catalise biochemical reactions without undergoing any change. A large number of enzymes are being used in biotechnological industry. Most of them are obtained from microbes. Proteases degrade proteins and polypeptides. Most of the commercially applicable proteases are alkaline and are biosynthesised mainly by bacteria such as Pseudomonas, Bacillus and some fungi like, Aspergillus. These enzymes are used in clearing beer, softening of bread and meat, degumming of silk, etc. Alkaline serine proteases have the largest applications in bio-industry. Alkaline proteases have shown their capability to work under high pH, temperature and in presence of inhibitory compounds. Another important group of enzymes is amylases. Amylolytic enzymes act on starch. These are obtained from Aspergillus, Rhizopus and Bacillus sp. These are used in softening and sweetening of bread, production of alcoholic beverages from starchy materials, clearing of turbidity in juices caused by starch, etc.

1. Polypeptides are degraded by:

1. Amylases.
2. Proteases.
3. Pectinases.
4. Lipases.

2. Amylolytic enzymes are not obtained from:

1. Aspergillus.
2. Aspergillus.
3. Mucor.
4. Bacillus.

3. Clearing of turbidity in juices caused by starch is achieved by:

1. Amylases.
2. Proteases.
3. Rennet.
4. Both (a) and (b).

4. Select the incorrect option from the following.

1. Enzymes are proteinaceous substances.
2. Enzymes are substrate specific.
3. Enzymes are large sized molecules.
4. Microbial enzymes can work only in normal temperature and pH.

5. A farmer harvests corns and prepares corn starch. He wants to prepare some corn syrup from this. for the conversion he needs to use enzyme ______.

1. Amylase.
2. Glucoamylases.
3. Glucoisomerases.
4. All of these.

Read the following and answer any four questions from (i) to (v) given below:
Green manuring is the fanning practice where a leguminous plant which has derived enough benefits from its association with appropriate species of Rhizobium, is ploughed into the field soil and then a non-legume is sown and allowed to get benefitted from the already present nitrogen fixer. Some legumes, such as, Crotolaria juncea, Sesbania rostrata, Lencaena leucocephala, etc. are used as green manure. Rhizobia, that fix atmospheric nitrogen in the form of nitrate, live in the roots ofleguminous plants. These nutrients are used by non-leguminous plants through the practice of green manuring.

1. Green manures mainly provide nutrient enriched in:

1. Magnesium.
2. Sulphur.
3. Nitrogen.
4. Both (a) and (b).

2. Which of the following plants is used as green manure in crop fields?

1. Saccharum.
2. Dichanthium.
3. Phyllonthus.
4. Crotolaria.

3. Green manure plants belong to the Family:

1. Lamiaceae.
2. Papilionaceae.
3. Liliaceae.
4. Poaceae.

4. Due to excess use of chemical fertilisers rich in nitrate, ________ disease occurred in children.

1. Jaundice.
2. Septicemia.
3. Methemoglobinemia.
4. Botulism.

5. A green manure is:

1. Rice.
2. Maize.
3. Sorghum.
4. Sesbania.

Read the following and answer any four questions from (i) to (v) given below:
When it comes to biopesticides, one of the most widely used fungi is Beauveria bassiana. It infects a range of insects like, pecan weevil, Colorado potato beetle, kudzu bug, etc. It causes a disease known as the white muscardine. Even after an insect is killed, the white mold continues to produce millions of new infective spores that are released into the environment. It is commercially formulated as products including Naturalis L, Mycotrol, BotaniGard, etc. Some other widely used molds are Trichoderma, Metarhizium, etc. Some of them release enzymes that dissolve potential pathogens, others form barriers around plant roots and make it impossible for harmful bacteria and pathogens to pass through.

1. The key benefits of the biopesticides are that they are:

1. Highly effective.
2. Target specific.
3. Reduced environmental risks.
4. all of these.

2. Naturalis-L is a conunercial formulation containing:

1. Bacterial biopesticide.
2. Fungal biopesticide.
3. Fungal biofertiliser.
4. Chemical pesticide.

3. Which of the following is used as an effective bacterial biopesticide?

1. Trichoderma.
2. Beauveria.
3. Bacillus thuringiensis.
4. All of these.

4. Baeuveria causes a disease called:

1. White muscardine.
2. Aspergillosis
3. Green muscardine.
4. Powdary mildews.

5. Assertion: Trichoderma, found in root ecosystem, exerts biological control over several plant pathogens.

Reason: Trichoderma release enzyme which inhibits growth of several disease causing pathogens.

1. Both assertion and reason are true and reason is the correct explanation of assertion.
2. Both assertion and reason are true but reason is not the correct explanation of assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Read the following and answer any four questions from (i) to (v) given below:
Disposal of untreated sewage into the river or freshwater pond causes huge water pollution. Four water samples from different sources (A, B, C, D) are collected and tested for BOD value in a lab to assess their quality. The BOD values are presented in the given table. Water samples are collected from primary effluent, secondary effluent, untreated sewage and river water. Study the given table and answer the following.

Sample	BOD
A	20mg/ L
B	5mg/ L
C	300mg/ L
D	400mg/ L

1. The source of sample 'C' is:

1. River water.
2. Primary effluent.
3. Secondary effluent.
4. Untreated sewage water.

2. If sewage in untreated condition is disposed off in a freshwater body then.

1. BOD and dissolved oxygen both will increase.
2. BOD will increase and dissolved oxygen will decreas.
3. BOD will decrease and dissolved oxygen will increase.
4. BOD and dissolved oxygen both will decrease.

3. A large number of pathogenic microbes can be present in water sample of:

1. C
2. A
3. D
4. Both (a) and (c).

4. High value of BOD in sample O is due to:

1. High amount of organic wastes and aerobic microbes.
2. High amount of inorganic wastes and anaerobic microbes.
3. High amount of organic wastes and anaerobic microbes.
4. High amount of inorganic wastes and aerobic microbes.

5. River water is represented by the sample.

1. A
2. B
3. C
4. D

Read the following and answer any four questions from (i) to (v) given below:
Saurin, a M.Sc student, get an assignment on sewage treatment plant (STP) to study the microbial load. After visiting such plant in his locality, he makes a simplified diagram of the STP for his project. Study the diagram given below and answer the following questions.

1. In the diagram 'A' denotes:

1. Aeration tank.
2. Primary settling tank.
3. Secondary settling tank.
4. Sludge digester.

2. Which of the following is incorrect regarding the sludge released from A?

1. It is formed after primary treatment.
2. It does not require aeration.
3. It possesses floes of decomposer microbes.
4. It is used in landfills.

3. A large number of aerobic heterotrophic microbes grow in:

1. A
2. B
3. C
4. Both (a) and (b).

4. What is denoted by 'D' in the given diagram?

1. Primary sludge.
2. Primary effluent.
3. Activated sludge.
4. Secondary effluent.

5. Assertion: The colloided and finely suspended matter of sewage form aggregates which are called floes.

Reason: Floes contain masses of bacteria, slime and fungal filaments.

1. Both assertion and reason are true and reason is the correct explanation of assertion.
2. Both assertion and reason are true but reason is not the correct explanation of assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Read the following and answer any four questions from (i) to (v) given below:
In today's world, more than 25% of human population is suffering from hunger and malnutrition. Scientists have developed techniques where microbes are grown on industrial scale as a source of good protein which can be grown from waste water, animal manure and even sewage. Single cell proteins are such products. TI1e biomass or protein is extracted from pure or mixed cultures of algae, yeasts, fungi or bacteria. These are a very good source of food for human consumption.

1. Why the name single cell protein is applied?

1. It contains only one type of protein.
2. It is obtained from unicellular edible microbes.
3. It contains only one type of microorganism.
4. All of these.

2. Which of the following is considered under single cell protein?

1. Algae.
2. Fungi.
3. Cyanobacteria.
4. All of these.

3. Microorganisms can be a useful food resource for increasing human population because:

1. These are easy to harvest.
2. These can grow in water system.
3. They have a high rate of multiplication thus producing huge biomass.
4. They have high level of nucleic acid.

4. Single cell protein can be grown from:

1. Waste water.
2. Animal manure.
3. Sewage.
4. All of these.

5. Assertion: Production of single cell protein reduces pollution.

Reason: Single cell protein can be grown from waste water and even sewage.

1. Both assertion and reason are true and reason is the correct explanation of assertion.
2. Both assertion and reason are true but reason is not the correct explanation of assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.