Important Terms to Learn Before Starting Making Notes 🗒
| Algae (शैवाल): Simple, typically aquatic plants that can perform photosynthesis. |
| Antibiotics (प्रतिजैविक): Medicines that inhibit the growth of or destroy bacteria. |
| Antibodies (एंटीबॉडी): Proteins produced by the immune system to neutralize pathogens like bacteria and viruses. |
| Bacteria (जीवाणु): Microscopic single-celled organisms that can be beneficial or cause diseases. |
| Carrier (वाहक): An organism that harbors a pathogen and transmits it to others without showing symptoms. |
| Communicable Diseases (संक्रामक रोग): Illnesses caused by pathogens that can be transmitted from one person to another. |
| Fermentation (किण्वन): The chemical breakdown of a substance by bacteria, yeast, or other microorganisms. |
| Fungi (कवक): A group of spore-producing organisms that feed on organic matter, including molds, yeast, and mushrooms. |
| Lactobacillus (लैक्टोबेसिलस): A type of bacteria that converts lactose into lactic acid and is used in the production of yogurt and other fermented foods. |
| Microorganism (सूक्ष्मजीव): Tiny living organisms, such as bacteria, viruses, and fungi, that can only be seen under a microscope. |
| Nitrogen Cycle (नाइट्रोजन चक्र): The series of processes by which nitrogen is converted into different chemical forms as it circulates among the atmosphere, terrestrial, and marine ecosystems. |
| Nitrogen Fixation (नाइट्रोजन स्थिरीकरण): The process by which nitrogen in the atmosphere is converted into ammonia or related nitrogenous compounds in soil. |
| Pasteurisation (पास्चुरीकरण): The process of heat-treating liquids to kill harmful bacteria without affecting the taste or quality of the product. |
| Pathogen (रोगज़नक): An organism that causes disease. |
| Preservation (संरक्षण): Methods to prevent food from spoiling by inhibiting the growth of microorganisms. |
| Protozoa (प्रोटोजोआ): Single-celled eukaryotes that can be free-living or parasitic. |
| Rhizobium (राइज़ोबियम): A type of bacteria that forms symbiotic relationships with legumes and fixes nitrogen from the atmosphere. |
| Vaccine (टीका): A substance used to stimulate the production of antibodies and provide immunity against diseases. |
| Virus (वायरस): A microscopic infectious agent that can only replicate inside the living cells of an organism. |
| Yeast (खमीर): A type of fungus used in baking and brewing for fermentation. |
Exercise Question Starts Here: Start Working 🖊️
1. Fill in the Blanks
(a) Microorganisms can be seen with the help of a microscope (सूक्ष्मदर्शी यंत्र). (b) Blue green algae fix nitrogen (नाइट्रोजन) directly from air and enhance fertility of soil. (c) Alcohol is produced with the help of yeast (खमीर). (d) Cholera is caused by bacteria (जीवाणु).
2. Tick the Correct Answer
(a) Yeast is used in the production of
- (i) sugar
- (ii) alcohol (शराब)
- (iii) hydrochloric acid
- (iv) oxygen
(b) The following is an antibiotic
- (i) Sodium bicarbonate
- (ii) Streptomycin (स्ट्रेप्टोमाइसिन)
- (iii) Alcohol
- (iv) Yeast
(c) Carrier of malaria-causing protozoan is
- (i) female Anopheles mosquito (मादा एनोफिलीज़ मच्छर)
- (ii) cockroach
- (iii) housefly
- (iv) butterfly
(d) The most common carrier of communicable diseases is
- (i) ant
- (ii) housefly (गृह मक्खी)
- (iii) dragonfly
- (iv) spider
(e) The bread or idli dough rises because of
- (i) heat
- (ii) grinding
- (iii) growth of yeast cells (खमीर कोशिकाओं का वृद्धि)
- (iv) kneading
(f) The process of conversion of sugar into alcohol is called
- (i) nitrogen fixation
- (ii) moulding
- (iii) fermentation (किण्वन)
- (iv) infection
3. Match the Organisms in Column A with Their Action in Column B
| A | B |
|---|---|
| (i) Bacteria | (e) Causing cholera |
| (ii) Rhizobium | (a) Fixing nitrogen |
| (iii) Lactobacillus | (b) Setting of curd |
| (iv) Yeast | (c) Baking of bread |
| (v) A protozoan | (d) Causing malaria |
| (vi) A virus | (f) Causing AIDS |
4. Can Microorganisms Be Seen with the Naked Eye? If Not, How Can They Be Seen?
No, microorganisms cannot be seen with the naked eye because they are too small. They can be seen with the help of a microscope (सूक्ष्मदर्शी यंत्र), which magnifies these tiny organisms, making them visible to the human eye.
5. What Are the Major Groups of Microorganisms?
The major groups of microorganisms are:
- Bacteria (जीवाणु)
- Fungi (कवक)
- Algae (शैवाल)
- Protozoa (प्रोटोजोआ)
- Viruses (वायरस)
6. Name the Microorganisms Which Can Fix Atmospheric Nitrogen in the Soil.
Microorganisms that can fix atmospheric nitrogen in the soil include:
- Rhizobium (राइजोबियम)
- Blue-green algae (Cyanobacteria) (नीला-हरा शैवाल)
7. Write 10 Lines on the Usefulness of Microorganisms in Our Lives.
- Microorganisms play a crucial role in the decomposition (अपघटन) of organic matter, recycling nutrients back into the ecosystem.
- Rhizobium bacteria fix atmospheric nitrogen, enriching soil fertility and aiding in plant growth.
- Lactobacillus bacteria are used in the production of curd, cheese, and other fermented dairy products.
- Yeast is used in the fermentation (किण्वन) process to produce bread, beer, and wine.
- Microorganisms are used in the production of antibiotics (एंटीबायोटिक्स), which are essential for treating bacterial infections.
- Certain algae are used as bio-fertilizers (जैव उर्वरक) to improve soil health.
- Microorganisms are involved in the production of vitamins (विटामिन) and other nutritional supplements.
- They are used in bioremediation (जैव उपचार) processes to clean up oil spills and toxic waste.
- Probiotics (प्रोबायोटिक्स), which are beneficial bacteria, are used to improve gut health.
- Microorganisms are used in the food industry (खाद्य उद्योग) for the production of items like soy sauce, vinegar, and sauerkraut.
8. Write a Short Paragraph on the Harmful Effects of Microorganisms.
Microorganisms can also have harmful effects on humans, animals, and plants. Some bacteria, viruses, fungi, and protozoa are pathogens that cause diseases. For example, bacteria like Vibrio cholerae cause cholera, while viruses like HIV cause AIDS. Fungi can cause infections such as athlete’s foot and ringworm. Protozoa such as Plasmodium cause malaria. These pathogens can spread through air, water, food, and physical contact, leading to outbreaks and epidemics. Additionally, certain microorganisms spoil food by growing on it and producing toxins, leading to foodborne illnesses. Harmful microorganisms also cause diseases in plants, reducing crop yield and affecting food supply.
9. What Are Antibiotics? What Precautions Must Be Taken While Taking Antibiotics?
Antibiotics (एंटीबायोटिक्स) are medicines that kill or inhibit the growth of bacteria and are used to treat bacterial infections. They are ineffective against viral infections.
Precautions while taking antibiotics:
- Take as prescribed: Always follow the doctor’s prescription regarding dosage and duration.
- Complete the course: Finish the entire course of antibiotics even if you feel better, to ensure all bacteria are eliminated and to prevent resistance.
- Avoid overuse: Do not use antibiotics for viral infections like colds or flu.
- Avoid self-medication: Do not take antibiotics without a doctor’s recommendation.
- Be aware of allergies: Inform your doctor of any known allergies to antibiotics.
- Avoid alcohol: Some antibiotics can interact with alcohol, reducing their effectiveness or causing side effects.
Other Chapter Question Answers: 👉
- Chapter 1 Crop Production And Management Question/Answer
- Chapter 2 Microorganisms: Friend And Foe Question Answers
- Chapter 3 Coal And Petroleum Question Answers
- Chapter 4 Combustion And Flame Question Answers
- Chapter 5 Conservation Of Plants And Animals Question Answers
- Chapter 6 Reproduction In Animals Question Answers
- Chapter 7 Reaching The Age Of Adolescence Question Answers
- Chapter 8 Force And Pressure Question Answers
- Chapter 9 Friction Question Answers
- Chapter 10 Sound Question Answers