Micro organisms 8th C

The virus causing yellow vein mosaic is a pathogen that specifically infects plants like bhindi (okra), while rhizobium, lactobacillus, and yeast are beneficial microorganisms.

Nitrogen fixation is the process by which atmospheric nitrogen (N₂) is converted into ammonia or other nitrogenous compounds that plants can absorb and use for growth.

The nitrogen cycle describes the continuous movement and transformation of nitrogen through the atmosphere, soil, living organisms, and back to the atmosphere.

Spirogyra is a genus of filamentous green algae commonly found in freshwater, while mushroom is a fungus, amoeba is a protozoan, and rhizobium is a bacterium.

Antibodies are Y-shaped proteins produced by white blood cells that specifically recognize and neutralize foreign substances like bacteria and viruses.

Yeast is a fungus that ferments sugars, producing carbon dioxide (which makes bread rise) and alcohol (used in beer and wine production).

Lactobacillus bacteria convert milk into curd through fermentation, producing lactic acid, and are known as probiotics that aid in digestion.

A vector or carrier transmits pathogens from one host to another without typically showing symptoms of the disease itself, such as mosquitoes carrying malaria.

Communicable diseases, also known as infectious diseases, are transmitted from an infected person to a healthy person through direct contact, air, water, or vectors.

Fermentation is an anaerobic process where microorganisms like yeast and bacteria break down sugars to produce energy, yielding byproducts such as alcohol, lactic acid, or carbon dioxide.

Ringworm is a fungal infection caused by dermatophytes, not a worm, and affects the skin, scalp, or nails.

Microorganisms, or microbes, are living organisms too small to be seen with the naked eye and require a microscope for observation.

Rhizobium bacteria form a symbiotic relationship with leguminous plants, living in root nodules and converting atmospheric nitrogen into a form the plant can use.

Pasteurization involves heating milk to a specific temperature for a set time to destroy harmful pathogens without significantly affecting the milk’s taste or nutritional value.

A pathogen is any microorganism, such as a bacterium, virus, fungus, or protozoan, that causes disease in its host.

Fermentation, pasteurization, and various preservation methods all help prevent food spoilage by inhibiting the growth of microorganisms.

Amoeba is a single-celled protozoan that moves using pseudopodia and feeds on bacteria and other small organisms.

BCG (Bacillus Calmette-Guérin) vaccine is derived from a weakened strain of Mycobacterium bovis and provides immunity against tuberculosis.

Viruses are considered non-living outside a host because they cannot carry out metabolic processes or reproduce independently; they become active only inside a living cell.

Microorganisms are microscopic, meaning they are so small that they cannot be observed without the aid of a microscope.

Microorganisms are remarkably adaptable and inhabit diverse environments, from polar ice caps to hot springs, deserts, and deep oceans.

Microorganisms are ubiquitous, present in virtually every habitat on Earth, including air, water, soil, and within the bodies of other living organisms.

Some microorganisms like bacteria and protozoa are unicellular, while others like many fungi and algae are multicellular.

Microorganisms include several distinct groups: bacteria, fungi, protozoa, viruses, and microscopic algae, each with unique characteristics.

Unlike bacteria, fungi, and protozoa, viruses lack cellular machinery and must hijack a host cell’s machinery to replicate.

Microorganisms like Penicillium (antibiotics) and yeast (alcohol) are used in industrial fermentation to produce pharmaceuticals and alcoholic beverages.

Entamoeba histolytica causes amoebic dysentery, while Plasmodium species are responsible for malaria, both serious protozoan diseases.

Pathogenic bacteria, such as Salmonella and E. coli, can grow on food and produce toxins that cause food poisoning when ingested.

Rhizobium bacteria form symbiotic structures called root nodules on leguminous plants, where they reside and carry out nitrogen fixation.

Nitrogen-fixing bacteria convert atmospheric nitrogen into ammonia, enriching the soil with usable nitrogen compounds that benefit the plant and surrounding vegetation.

Certain free-living bacteria (like Azotobacter) and cyanobacteria (blue-green algae) possess the enzyme nitrogenase and can fix atmospheric nitrogen independently.

Decomposers like bacteria and fungi break down dead organic matter, recycling nutrients back into the ecosystem for use by other organisms.

Denitrifying bacteria convert nitrates in the soil back into atmospheric nitrogen (N₂), completing the nitrogen cycle.

Rust of wheat is caused by a fungus (Puccinia species), while citrus canker is bacterial and yellow vein mosaic is viral.

Plants absorb nitrogen primarily as nitrates (NO₃⁻) and nitrites (NO₂⁻) through their roots, as atmospheric nitrogen is unusable directly by most plants.

Photosynthesis is part of the carbon and oxygen cycles, not the nitrogen cycle, which involves nitrogen fixation, nitrification, ammonification, and denitrification.

Algae, such as seaweed and spirulina, are consumed as food and produce a significant portion of Earth’s oxygen through photosynthesis.

B lymphocytes, a type of white blood cell, produce antibodies in response to the presence of antigens like pathogens.

Yeast fermentation produces carbon dioxide for leavening bread and alcohol for brewing beer, wine, and other alcoholic beverages.

High concentrations of salt or sugar create an environment where water is drawn out of microbial cells through osmosis, inhibiting their growth and reproduction.

Influenza is a viral communicable disease that spreads from person to person through respiratory droplets, unlike non-communicable diseases like diabetes, heart disease, and cancer.

The mosquito is a biological vector that transmits the Plasmodium pathogen from an infected person to a healthy person without itself being affected by the disease.

Penicillin was discovered by Alexander Fleming and is derived from the Penicillium fungus, which produces the antibiotic to inhibit bacterial growth.

The poliovirus infects the nervous system, specifically the spinal cord and brainstem, potentially causing paralysis.

Lactobacillus bacteria ferment lactose in milk, producing lactic acid that coagulates milk proteins to form curd or yogurt.

Blue-green algae are now scientifically classified as cyanobacteria, a phylum of bacteria that obtain energy through photosynthesis.

Nitrification is the two-step aerobic process carried out by nitrifying bacteria that oxidize ammonia (NH₃) to nitrite (NO₂⁻) and then to nitrate (NO₃⁻).

Vaccines introduce harmless antigens that trigger the immune system to produce antibodies and memory cells, providing immunity without causing the disease.

Refrigeration slows down the growth of microorganisms by maintaining low temperatures, thereby extending the shelf life of perishable foods.

Extremophiles are microorganisms adapted to survive and thrive in extreme conditions such as high temperature, high salinity, or extreme pH.

Citrus canker is caused by the bacterium Xanthomonas axonopodis, which infects citrus trees, causing lesions on leaves, fruits, and stems.

Rhizobium bacteria are symbiotic nitrogen fixers that convert atmospheric nitrogen into ammonia within the root nodules of leguminous plants.

Antibodies have a lock-and-key specificity, meaning each antibody is designed to recognize and bind to a specific antigen.

Ammonification is the decomposition process where bacteria and fungi convert organic nitrogen from dead organisms into ammonia (NH₃).

After infection, the immune system retains memory B and T cells that can rapidly mount a strong antibody response upon re-exposure, providing long-term immunity.

Azotobacter is a free-living aerobic bacterium found in soil that fixes atmospheric nitrogen independently, without forming symbiotic relationships with plants.

Malaria is transmitted through the bite of an infected female Anopheles mosquito, which acts as a vector for the Plasmodium protozoan.

Active immunity from vaccination stimulates the body to produce its own memory cells, typically providing long-lasting protection, often for years or a lifetime.

Atmospheric nitrogen (N₂) makes up approximately 78% of Earth’s atmosphere but cannot be used directly by most organisms; it must first be fixed into usable nitrogen compounds.

Yeast ferments sugars in the dough, releasing carbon dioxide gas that forms bubbles, causing the dough to rise and giving bread its soft, spongy texture.