Microbes can be used to decrease the use of chemical fertilizers and pesticides. Explain how this can be accomplished.
Solution and Explanation
Microbes play important role in organic farming which is done without the use of chemical fertilizers and pesticides. Bio-fertilisers are living organisms which help increase the fertility of soil. It involves the selection of beneficial micro-organisms that help in improving plant growth through the supply of plant nutrients. Bio-fertilisers are introduced in seeds roots or soil to mobilize the availability of nutrients. Thus they are extremely benificial in enriching the soil with organic nutrients. Many species of bacteria and cyanobacteria have the ability to fix free atmospheric nitrogen. Rhizobium is a symbiotic bacteria found in the root nodules of leguminous plants. Azospirillium and Azotobocter are free living nitrogen-fixing bacteria whereas Anabena Nostoc and Oscillitoria are examples of nitrogen-fixing cyanobacteria. Bio-fertilizers are cost effective and eco-friendly.
Microbes can also act as bio-pesticides to control insect pests in plants. An example of bio-pesticides is Bacillus thuringiensis which produces a toxin that kills the insect pests. Dried bacteruial spores are mixed in water and sprayed in agricultural fields. When larvae of insects feed on crops these bacterial spores enter the gut of the larvae and release toxins thereby it. Similarly Trichoderma are free living fungi. They live in the roots of higher plants and protect them from various pathogens. Baculoviruses is another bio-pesticide that is used as a biological control agent against insect and other arthropods.
Top Questions on Microbes in human welfare
- A farmer notices that the leaves of his cabbage plants are curling up because of heavy infestation of aphids. Suggest one ecofriendly method to control their spread in the cabbage plants.
- ICSE Class XII - 2026
- Biology
- Microbes in human welfare
- Define Biopiracy with reference to Basmati rice.
- RBSE Class XII Exam - 2026
- Biology
- Microbes in human welfare
- Match the following:
- TS EAMCET - 2025
- Zoology
- Microbes in human welfare
- Match the following
- TS EAMCET - 2025
- Zoology
- Microbes in human welfare
- Consider the following statements Statement I: In the crop of female {Anopheles}, microgametes of {Plasmodium} are separated from the microgametocyte by ex-flagellation. Statement II: Schuffner's dots are believed to be the antigens released by {Plasmodium}. The correct answer is
- TS EAMCET - 2025
- Zoology
- Microbes in human welfare
Questions Asked in CBSE CLASS XII exam
- The rate for the following reaction is given by: \[ A + B \rightarrow C, \quad \text{Rate} = k[A][B]^2 \] How is the rate affected if we double the concentration of B?
- CBSE CLASS XII - 2026
- Chemical Kinetics
- Find the general solution of the differential equation \[ y\log y\,\frac{dx}{dy}+x=\frac{2}{y}. \]
- CBSE CLASS XII - 2026
- Differential Equations
- A square loop of side 0.50 m is placed in a uniform magnetic field of 0.4 T perpendicular to the plane of the loop. The loop is rotated through an angle of 60° in 0.2 s. The value of emf induced in the loop will be:
- CBSE CLASS XII - 2026
- Electromagnetic induction
A racing track is built around an elliptical ground whose equation is given by \[ 9x^2 + 16y^2 = 144 \] The width of the track is \(3\) m as shown. Based on the given information answer the following:
(i) Express \(y\) as a function of \(x\) from the given equation of ellipse.
(ii) Integrate the function obtained in (i) with respect to \(x\).
(iii)(a) Find the area of the region enclosed within the elliptical ground excluding the track using integration.
OR
(iii)(b) Write the coordinates of the points \(P\) and \(Q\) where the outer edge of the track cuts \(x\)-axis and \(y\)-axis in first quadrant and find the area of triangle formed by points \(P,O,Q\).
- CBSE CLASS XII - 2026
- Integration
- Consider a cylindrical conductor of length \( l \) and area of cross-section \( A \). Current \( I \) is maintained in the conductor and electrons drift with velocity \( \vec{v}_d \, (|\vec{v}_d| = \frac{eE}{m} \tau) \), where symbols have their usual meanings. Show that the conductivity of the material of the conductor is given by \[ \sigma = \frac{n e^2 \tau}{m}. \]
- CBSE CLASS XII - 2026
- Current Density
Concepts Used:
Microbes in Human Welfare
There are several valuable microorganisms that are beneficial to humans in various manners such as:
In Household Products
- Fermentation of milk to produce yogurt.
- Milk cuddling to compose curd, cheese, and paneer.
In Industrial Products
- Production of beverages such as wine, beer, whiskey, brandy, or rum.
- Production of antibiotics such as Penicillin and other chemical substances to kill or retard the expansion of disease-causing microbes.
Fermented Beverages
- A fermentor is used to produce microbes on a large scale for industrial purposes.
- The brewer’s yeast (Saccharomyces cerevisiae) is used to make ethanol. At this time, the yeast ferments malted cereals and fruit juices.
Antibiotics
- The term antibiotic means “against life”. These materials can kill or destroy the growth of other microbes.