All questions of Daily Practice & Tests for NEET Exam

The answer Is D
because it is source of penicillin. a widely used antibiotic(B lactam antibiotic).
penicillin is anti bacterial drug

Heterocysts contain nitrogenase enzyme which helps to carry out nitrogen fixation.Nostoc show symbiotic association with corralloid roots of cycas and carries out nitrogen fixation.

Reninn also called as chymosin protein digesting enzymes that curdles milk by transforming caseinigen into indulge casein it is found only in the fourth stomach of cud chewing animals such as cows its action extend the period in which milk is retained in the stomach of the young animal in animal that reninn milk is coagulated by the action of person as the case in humans A commercial form of reninn and rennet is used in manufacturing cheese and preparing junket also .

Microbe Used in Commercial Production of Ethanol

The microbe used in the commercial production of ethanol is Saccharomyces cerevisiae.

Explanation

Saccharomyces cerevisiae is a yeast that is commonly used in the fermentation process to produce ethanol. It is a single-celled organism that feeds on sugar and converts it into alcohol and carbon dioxide. In the production of ethanol, Saccharomyces cerevisiae is added to a mixture of sugar and water, which is then left to ferment for a period of time. During this process, the yeast consumes the sugar and produces ethanol as a by-product.

Advantages of Using Saccharomyces cerevisiae

There are several advantages to using Saccharomyces cerevisiae in the production of ethanol:

1. High Yield: Saccharomyces cerevisiae is known for its high ethanol yield, which makes it a popular choice for commercial producers.

2. Fast Fermentation: Saccharomyces cerevisiae is a fast-fermenting yeast, which means that it can produce ethanol quickly.

3. Easy to Handle: Saccharomyces cerevisiae is easy to handle and can be stored for long periods of time.

4. Cost-effective: Saccharomyces cerevisiae is a cost-effective option for ethanol production.

Conclusion

In conclusion, Saccharomyces cerevisiae is the microbe used in the commercial production of ethanol. It is a fast-fermenting yeast that is known for its high ethanol yield and is cost-effective to use.

Selman Waksman, the microbiologist who discovered streptomycin, first used the word "antibiotic" in the medical sense in 1943. Science historian Howard Markel talks about how it was actually a naval officer who first coined "antibiotic" in 1860, to describe an opposition to the belief in life beyond Earth

Antibiotics does not work for viruses because antibiotics attack cell wall but viruses do not have cell wall

NCERT 12th page no. 188

The activated sludge process is a type of wastewater treatment process for treating sewage or industrial wastewater using aeration and a Biological floc composed of bacteria and protozoa.Thats it.

Probiotics are live bacteria and yeasts that are good for you, especially your digestive system. We usually think of these as germs that cause diseases. But your body is full of bacteria, both good and bad. Probiotics are often called "good" or "helpful" bacteria because they help keep your gut healthy. You can find probiotics in supplements and some foods, like yogurt. Doctors often suggest them to help with digestive problems. When you lose "good" bacteria in your body, for example after you take antibiotics, probiotics can help replace them. They can help balance your "good" and "bad" bacteria to keep your body working the way it should.

Organic farming includes all fertilizers made by biotic components and which are not artificial synthesise it includes green manure,farmyard manure, compost , cattle dung etc. so the option is B)

Assertion: A small part of activated sludge is pumped back into aeration tank to serve as the inoculum.

Reason: Remaining part of the sludge is pumped into large tanks called anaerobic sludge digester.

Explanation:

Activated sludge process is a biological treatment process used in wastewater treatment plants. In this process, wastewater is mixed with a microbial culture called activated sludge, which contains microorganisms that break down organic matter present in wastewater.

The given assertion is correct because a small part of activated sludge is pumped back into the aeration tank to maintain the microbial population and to provide a fresh supply of microorganisms to break down organic matter in wastewater.

The given reason is also correct because the remaining part of the sludge is pumped into large tanks called anaerobic sludge digesters. These tanks are designed to operate in the absence of oxygen, and the sludge is decomposed by anaerobic bacteria to produce biogas, which can be used as a source of energy.

Therefore, both the assertion and reason are correct, and option C is the correct answer.

In summary:

- Activated sludge process uses a microbial culture to break down organic matter in wastewater.
- A small part of activated sludge is pumped back into the aeration tank to maintain the microbial population.
- The remaining part of the sludge is pumped into anaerobic sludge digesters to produce biogas.
- Both the assertion and reason are correct.

No

Lactic acid is rich in Vitamin B12.

Fermentation is the process of producing ATP in the absence of oxygen, through glycolysis alone. that the glycolysis breaks a glucose molecule into two pyruvate molecules, producing a net gain of two ATP and two NADH molecules.

The raw material for biogas production is excreta (dung) of cattle. The biogas plant consists of a concrete tank (10-15 feet deep) in which bio-wastes are collected and slurry of dung is fed. A floating cover is placed over the slurry, which keeps on rising as the gas is produced in the tank due to the microbial activity. Methano bacterium in the dung act on the bio-wastes to produce bio-gas. The gas produced is supplied to nearby houses by an outlet. Through another outlet, the spent slurry is removed to be used as manure. 

Introduction:
Chemical/synthetic fertilizers have been widely used in agriculture to promote plant growth and increase crop yields. However, there is a growing realization that these fertilizers have negative impacts on the environment, human health, and the economy. Biofertilizers, on the other hand, offer a sustainable and eco-friendly alternative to chemical fertilizers. In this response, we will discuss the reasons why chemical/synthetic fertilizers should be replaced by biofertilizers.

Environmental Pollution:
- Chemical/synthetic fertilizers contain high concentrations of nitrogen, phosphorus, and potassium, which are essential nutrients for plant growth.
- When these fertilizers are applied to the soil, excess nutrients can leach into groundwater or runoff into nearby water bodies, causing water pollution.
- This nutrient pollution leads to the growth of harmful algal blooms, oxygen depletion, and disruption of aquatic ecosystems.
- Moreover, chemical fertilizers contribute to air pollution through the release of greenhouse gases such as nitrous oxide, which is a potent contributor to climate change.
- Biofertilizers, on the other hand, are made from natural sources such as plant residues, animal manure, and microbial cultures.
- They release nutrients slowly and in a form that is readily available to plants, minimizing the risk of nutrient runoff and pollution.

Expensive:
- Chemical/synthetic fertilizers are typically produced through energy-intensive processes that require fossil fuels.
- The manufacturing, transportation, and storage of these fertilizers contribute to their high cost.
- On the other hand, biofertilizers can be produced locally using organic waste materials, reducing the cost of production.
- Additionally, the use of biofertilizers can improve soil fertility and reduce the need for synthetic fertilizers in the long run, leading to cost savings for farmers.

Exhaustion of Energy Resources:
- The production of chemical/synthetic fertilizers relies heavily on non-renewable energy sources such as natural gas and petroleum.
- These energy resources are limited and contribute to greenhouse gas emissions.
- In contrast, biofertilizers utilize renewable energy resources such as solar energy through the process of photosynthesis in plants.
- By replacing chemical fertilizers with biofertilizers, we can reduce the demand for non-renewable energy resources and promote sustainable agricultural practices.

Conclusion:
The replacement of chemical/synthetic fertilizers with biofertilizers is crucial for addressing environmental pollution, reducing costs, and conserving valuable energy resources. Biofertilizers offer a sustainable and eco-friendly alternative that promotes soil health, improves crop productivity, and minimizes the negative impacts on the environment. By adopting biofertilizers, we can move towards a more sustainable agricultural system that benefits both the present and future generations.

Statement a: The majority of baculoviruses used as biocontrol agents are included in the genus - Nucleopolyhedrovirus.

Explanation: This statement is correct. Baculoviruses are a family of viruses that infect insects. The majority of baculoviruses used as biocontrol agents belong to the genus Nucleopolyhedrovirus (NPV). NPVs are highly specific to certain insect species and are widely used in biocontrol programs to target specific pests.

Statement b: Infection with baculoviruses occurs when susceptible hosts (e.g., some specific insects) eat virus particles present on foliage and die.

Explanation: This statement is correct. Baculoviruses have a unique mode of transmission. Infection occurs when susceptible hosts, such as specific insects, consume virus particles that are present on foliage or other food sources. Once ingested, the virus particles replicate within the insect's body, leading to the death of the host.

Statement c: Baculoviruses are important in organic farming because of their specific action on harmful insects without causing any damage to beneficial insects as well as to the environment.

Explanation: This statement is correct. Baculoviruses are highly specific to certain insect species and do not have a broad spectrum of activity. This specificity makes them ideal for use in organic farming, where the goal is to control harmful insect pests while minimizing harm to beneficial insects and the environment. Baculoviruses have been successfully used in organic agriculture to control pests like the corn earworm, cabbage looper, and gypsy moth.

Therefore, all of the given statements (a, b, and c) are correct. Baculoviruses, specifically those belonging to the genus Nucleopolyhedrovirus, are widely used as biocontrol agents. Infection occurs when susceptible hosts consume virus particles, and these viruses are important in organic farming due to their specific action on harmful insects without causing damage to beneficial insects or the environment.

Introduction:
Biocontrol agents are organisms that are used to control pests, diseases, and weeds in agriculture and other ecosystems. They are a sustainable and environmentally friendly alternative to chemical pesticides. In this question, we are given four statements about biocontrol agents and asked to choose the correct one.

Explanation:

Statement a: Ladybird and dragonflies are used to get rid of aphids and mosquitoes respectively.

Explanation:
Ladybirds are commonly used as biocontrol agents to control aphids, which are pests that damage crops. Ladybirds feed on aphids and help in reducing their population. Dragonflies, on the other hand, are natural predators of mosquitoes. They feed on mosquito larvae, helping to control their population. Therefore, statement a is correct.

Statement b: Bacillus thuringiensis bacteria are used to control butterfly caterpillars.

Explanation:
Bacillus thuringiensis (Bt) is a type of bacteria that produces toxins that are harmful to certain insect pests, including butterfly caterpillars. When these bacteria are ingested by the caterpillars, the toxins disrupt their digestive system, leading to their death. Bt is commonly used as a biocontrol agent to control butterfly caterpillars in agricultural settings. Therefore, statement b is correct.

Statement c: Trichoderma species are used to control several plant pathogens.

Explanation:
Trichoderma is a genus of fungus that is known for its biocontrol properties. It has the ability to suppress the growth of various plant pathogens, including fungi, bacteria, and nematodes. Trichoderma species produce enzymes and secondary metabolites that inhibit the growth of pathogens and promote plant growth. They are commonly used as biocontrol agents in agriculture to control diseases caused by plant pathogens. Therefore, statement c is correct.

Conclusion:
From the explanations provided above, it can be concluded that all of the given statements (a, b, and c) are correct. Therefore, the correct answer is option 'D' - All of these.

Understanding Primary Treatment of Sewage
Primary treatment is the initial stage in wastewater management, focusing on the physical removal of contaminants. This process is essential for reducing the load on subsequent treatment stages.
Key Processes Involved:
- Filtration:
- Large particles, such as plastics and debris, are removed by passing sewage through filters.
- Sedimentation:
- Smaller particles and solids settle at the bottom of a sedimentation tank, forming sludge. This process allows for the separation of heavier particles from the liquid.
Purpose of Primary Treatment:
- Reduce Solid Waste:
- By eliminating a significant portion of solids, primary treatment minimizes the burden on secondary and tertiary treatments, which focus on biological and chemical processes.
- Improve Water Quality:
- The removal of suspended solids helps in improving the overall quality of wastewater, making it less harmful for the environment.
Distinguishing from Other Treatments:
- Secondary Treatment:
- Involves biological processes to break down organic matter.
- Tertiary Treatment:
- Further polishing of the effluent, often involving advanced filtration and chemical treatments to remove remaining nutrients and pathogens.
- Quaternary Treatment:
- An emerging and less commonly referenced stage, focusing on advanced purification processes.
Conclusion:
The primary treatment stage is crucial for effective sewage management. It sets the foundation for further treatment processes, ensuring that wastewater is treated efficiently and safely before being released back into the environment.

Dough Puffing in Dosa and Idli

The correct answer to the question is option 'B', which is bacterial fermentation producing CO2 gas. This process is responsible for the puffing up of the dough used for making foods like dosa and idli.

Bacterial Fermentation
- The dough used to make dosa and idli is typically made by soaking and grinding rice and lentils together.
- After grinding, the batter is left to ferment for a certain period of time, usually overnight.
- During this fermentation process, the carbohydrates present in the batter are broken down by bacteria into simpler compounds such as glucose and fructose.
- The bacteria involved in this process are primarily lactic acid bacteria, such as Lactobacillus species.
- As a byproduct of their metabolic activity, these bacteria produce carbon dioxide gas (CO2).

CO2 Production and Puffing Up
- The carbon dioxide gas produced by the bacteria gets trapped within the batter due to its sticky and viscous consistency.
- As the gas accumulates, it creates bubbles within the batter, causing it to rise and expand.
- This process is similar to the way yeast fermentation causes bread dough to rise.
- The trapped carbon dioxide gas is responsible for the light and fluffy texture of dosa and idli.

Other Factors
- While bacterial fermentation is the primary cause of dough puffing, other factors also contribute to the final texture of dosa and idli.
- The grinding process helps in aerating the batter and incorporating air into it, which further enhances the fluffiness.
- The unique composition of rice and lentils also plays a role in creating a spongy texture.
- The high protein content in the lentils contributes to the overall structure and texture of the final product.

In conclusion, the dough used for making foods like dosa and idli puffs up due to bacterial fermentation producing carbon dioxide gas. This gas gets trapped within the batter, causing it to rise and create a light and fluffy texture.

Introduction to Roquefort Cheese
Roquefort cheese, a famous blue cheese from France, is renowned for its distinct flavor and appearance. Its unique characteristics are developed during the ripening process, which is significantly influenced by specific fungi.
Role of Fungi in Ripening
- The ripening of Roquefort cheese is primarily facilitated by the growth of the fungus *Penicillium roqueforti*.
- This specific fungus is responsible for creating the blue veins in the cheese, which are not only visually striking but also contribute to its complex flavor profile.
Process of Ripening
- The cheese is made from sheep's milk and is initially inoculated with *Penicillium roqueforti* during the cheese-making process.
- As the cheese ages in the natural caves of Roquefort-sur-Soulzon, the fungus thrives in the moist and cool conditions, breaking down proteins and fats.
Flavor Development
- The enzymatic activity of *Penicillium roqueforti* leads to the production of various compounds that enhance the flavor, aroma, and texture of the cheese.
- This results in the tangy, sharp taste that Roquefort is famous for, distinguishing it from other cheeses.
Conclusion
In summary, Roquefort cheese is ripened with the aid of specific fungi, primarily *Penicillium roqueforti*, which plays a critical role in developing its unique characteristics. This fungal influence is what makes Roquefort a celebrated cheese in culinary traditions worldwide.

Answer is b

A