Blue Green algae are a type of photosynthetic bacteria consisting either of single cells or colonies which is also known as the Cyanobacteria. Cyanobacteria contain only one type of chlorophyll, Chlorophyll a, a green pigment. In addition, they also contain pigments such as carotenoids, phycobilin.

These bacteria grow naturally in marine and freshwater systems. They thrive in dams, rivers, reservoirs, lakes and even in hot springs. These bacteria normally look green and sometimes turns blue when scum are dying. Almost all species of these bacteria are buoyant and float on the water surface and forms floating mats.

Blue-green algae have been used for food for several centuries in Mexico and some African countries. They have been sold as a supplement in the US since the late 1970s. Blue-green algae products are sometimes used by mouth as a protein supplement and for treating high blood pressure.

• Microbes play a vital role in preparing curd from milk. Curd contains a bacterium, Lactobacillus
• Lactobacillus is a friendly-bacterium. It treats & prevents diarrhea, helps in food breakdown and absorption of nutrients.

Lactobacillus is a genus of Gram-positive, facultative anaerobic or microaerophilic, rod-shaped, non-spore-forming bacteria. Lactobacillus is the most common probiotic found in food such as yogurt, and it is diverse in its application to maintain human well-being, as it can help treat diarrhea, vaginal infections, and skin disorders such as eczema.

The process of removing a plant from the place where it has been growing and replanting it in another is called transplantation.
Tomato and paddy are examples of crops grown by transplantation.

It is the use of microorganisms to help decompose pollutants.

Undesirable plants that grow naturally along with the crop are known as weeds. It can be controlled by the process of weeding. Weeding involves the removal of unwanted and uncultivated plants called weeds.

Examples commonly are plants unwanted in human-controlled settings, such as farm fields, gardens, lawns, and parks.

Animals are classified based on their characteristics. They are eminent from algae, plants, and fungus where rigid cell walls are absent. Some are also heterotrophic, in general, they digest their food within the internal chambers which again distinguish them from algae and plants. Another elite character of these species is that they are motile, except in certain life stages.

When a solution of magnesium salts is combined with alkaline water it instigates precipitation of solid magnesium hydroxide. The reaction is as follows:

Mg²⁺ + 2 OH⁻ → Mg(OH)₂

Commercially it is produced by treating lime and sea water. Approximately one ton of magnesium hydroxide is obtained from 600 m³ of seawater. Calcium hydroxide is more soluble in magnesium hydroxide therefore Mg(OH)₂ precipitates as a solid. The reaction is as follows:

MgO + H2O → Mg(OH)₂

Monkombu Sambasivan Swaminathan is a well-known Indian agricultural scientist. 

Dr. MS Swaminathan is known as the Father Of India's Green Revolution

Compost contains the full spectrum of plant nutrients, although the exact amounts vary from sample to sample. Well rotted compost is rich in all of the three main fertilizer nutrients: Nitrogen, Phosphorus, Potassium.
In addition, compost contains micronutrients and trace minerals that are often missing from commercial fertilizer, such as: Sulphur, Carbon, Magnesium, Calcium, Boron, Copper, Iron, Iodine, Zinc and Manganese.

In agriculture and gardening transplanting or replanting is the technique of moving a plant from one location to another. In the horticulture of some ornamental plants, transplants are used infrequently and carefully because they carry with them a significant risk of killing the plant. The process of removing a plant from the place where it has been growing and replanting it in another is called transplantation. Tomato and paddy are examples of crops grown by transplantation. Answer: ... Seedlings are then transplanted into the regular fields placing them at a proper distance from one another.

Following are the important chloroplast function:

• The most important function of the chloroplast is to synthesize food by the process of photosynthesis.
• Absorbs light energy and converts it into chemical energy.
• Chloroplast has a structure called chlorophyll which functions by trapping the solar energy and used for the synthesis of food in all green plants.
• Produces NADPH and molecular oxygen(O2) by photolysis of water.
• Produces ATP – Adenosine triphosphate by the process of photosynthesis .
• The carbon dioxide (CO2) obtained from the air is used to generate carbon and sugar during the Calvin Cycle or dark reaction of photosynthesis.

The modern methods of irrigation help us to use water economically. The two main modern methods of irrigation are:

1.  Sprinkler system – In sprinkler system of irrigation, a main pipe is laid in the fields to which perpendicular pipes are joined at regular intervals. When water from a tube-well is allowed to flow through the main pipeline under pressure with the help of a pump, it escapes from the rotating nozzles and gets sprinkled on the crops. This method of irrigation is more useful for the uneven land and sandy soil where sufficient water is not available.
2. Drip system – In the drip system, there is a network of narrow pipes with small holes in the fields. When water falls through these narrow pipes, it falls drop by drop at the position of the roots of the plants. There is no run-off or wastage of water. This technique is the best technique for watering fruit plants, trees and gardens.

1. Fuel oil: It is used in industries.
2. Petrol: It is used as a fuel in motor, aviation and as a solvent for dry cleaning.
3. Diesel: It is used as a fuel for heavy motor vehicles and electric generators.
4. Kerosene: It is used as a fuel for domestic purposes such as burning lamps, stoves and in jet aircraft.
5. Liquefied petroleum gas (LPG): It is a flammable mixture of hydrocarbon gases used as a fuel for home and in industry.

Friendly Microorganisms:

Microorganisms are used for various purposes by human beings as well as in nature. Some of the beneficial effects of microorganisms are as follows:

1. Microorganisms are used in the production of alcohol, wine and acetic acid.
2. They are used in making curd, bread and cake.
3. They are used in the preparation of medicines called antibiotics.
4. They are used in agriculture to increase the fertility of soil by fixing atmospheric nitrogen gas.
5. They clean up the environment by decomposing the organic matter of dead plants, dead animals and animal wastes into harmless and useful simple substances.

Microorganisms can be harmful in many ways. For example – some of the microorganisms cause diseases in human beings, other animals and plants. Such microorganisms which cause diseases are called pathogens.

Sunflower oil provide us carbohydrates

Nitrogen fixation is the process by which atmospheric nitrogen is converted either by a natural or an industrial means to a form of nitrogen such as ammonia. In nature, most nitrogen is harvested from the atmosphere by microorganisms (see above) to form ammonia, nitrites, and nitrates that can be used by plants. Examples of symbiotic nitrogen-fixing bacteria include Rhizobium, which is associated with plants in the pea family, and various Azospirillum species, which are associated with cereal grasses.

• Hypertension: It is a direct result of noise pollution which is caused due to elevated blood levels for a longer duration.
• Hearing loss: Constant exposure of human ears to loud noise that are beyond the range of sound that human ears can withstand damages the eardrums resulting in loss of hearing.
• Sleeping disorders: Lack of sleep might result in fatigue and low energy level throughout day affecting everyday activities. Noise pollution hampers the sleep cycles leading to irritation and uncomfortable state of mind.
• Cardiovascular issues: Heart related problems such as blood pressure level, stress, and cardiovascular diseases might come up in a normal person and person suffering from any of these diseases might feel the sudden shoot up in the level.

An enormous variety of organisms exist, including some which can survive and even develop in the body of the host. If the organism can cause infectious diseases, it is an infectious agent. In this manual infectious agents which cause infection and illness are called pathogens.