Chapter- 2 Microorganisms: Friend and Foe
Que 1
Fill in the blanks.
Answer
(a) Microorganisms can be seen with the help of a _microscope____
(b) Blue-green algae fix __nitrogen____ directly from the air to enhance the fertility of soil.
(c) Alcohol is produced with the help of __yeast___
(d) Cholera is caused by _bacteria_____
Question 2.
Tick the correct answer.
(a) Yeast is used in the production of
(i) sugar ii) alcohol(iii) hydrochloric acid(iv) oxygen
Answer:
(ii) alcohol
(b) The following is an antibiotic:
(i) sodium bicarbonate(ii) streptomycin(iii) alcohol(iv) yeast
Answer:
(ii) streptomycin
(c) Carrier of malaria-causing protozoan is:
(i) female Anopheles mosquito{ii) cockroach(iii) housefly(iv) butterfly
Answer:
(i) female Anopheles mosquito
(d) The most common carrier of communicable diseases is
(i) ant(ii) housefly(iii) dragonfly(iv) spider
Answer:
(ii) housefly
(e) The bread or idli dough rises because of:
(i) heat(ii) grinding(iii) growth of yeast cells(iv) kneading
Answer:
(iii) growth of yeast cells
(f) The process of conversion of sugar into alcohol is called
(i) nitrogen fixation(ii) moulding(iii) fermentation(iv) infection
Answer:
(iii) fermentation
Question 3.
Match the organisms in column A with their action in column B.
a b
(1) Bacteria {a}fixing nitrogen
(2) Rhizobium {b}setting of curd
(3) Lactobacillus {c} Baking of bread
{4} Yeast {d} Causing malaria
{5} A protozoan {e} causing cholera
{6} A virus {f} causing A
{g }Producing antibodies
Answer:
(i) (e)(ii) (a)(iii) (b)(iv) (c)(v) (d)(vi) (f)
Questions-4
Can microorganisms be seen with the naked eye? If not, how can they be seen?
Ans -Microorganisms, such as bacteria, viruses, and fungi, are typically too small to be seen with the naked eye. They are microscopic, which means they are smaller than what the human eye can detect without the aid of tools.
Question 5.
What are the major groups of microorganisms?
Ans-Microorganisms can be broadly classified into several major groups based on their characteristics, cellular structure, and other features. The major groups of microorganisms include:
**Bacteria:** 2. **Viruses 3. **Fungi:**4. **Protozoa:** 5. **Algae:** 6. **Archaea
Question- 6 Name the microorganisms which can fix atmospheric nitrogen i
Answer
1. **Rhizobia:**
2. **Cyanobacteria:**
3. **Azotobacter:**
4. **Frankia:**
Questions-7 Write 10 lines on the usefulness of microorganisms in our lives.
Answer:
Microorganisms play indispensable roles in various aspects of our lives:
1. **Medicine:** They’re crucial in producing antibiotics, vaccines, and other drugs that combat infections and diseases, improving global health.
2. **Food Production:** Microbes are used in fermentation processes to create foods like yogurt, cheese, bread, and pickles, enhancing taste and preservation.
3. **Environmental Cleanup:** Certain microorganisms aid in bioremediation, breaking down pollutants and contaminants in soil, water, and air.
4. **Agriculture:** They facilitate nitrogen fixation, helping plants obtain essential nutrients and boosting crop yields. Some microbes also act as natural pesticides.
5. **Waste Management:** Microorganisms decompose organic matter in composting and sewage treatment, contributing to waste breakdown and recycling.
6. **Biotechnology:** They’re harnessed in genetic engineering, producing enzymes, and creating biofuels, offering sustainable alternatives.
7. **Research:** Microbes serve as model organisms in scientific research, helping us understand fundamental biological processes.
8. **Probiotics:** Beneficial bacteria support gut health and digestion, and they’re increasingly used in dietary supplements and functional foods.
9. **Industry:** Enzymes produced by microorganisms are used in various industrial processes, from textile production to biofuel manufacturing.
10. **Ecosystem Function:** They’re vital in nutrient cycling, playing roles in the decomposition of organic matter and supporting ecological balance.
Questions-8
Write a short paragraph on the harms caused by microorganisms.
Ans-Microorganisms, while incredibly diverse and beneficial in many ways, also pose significant threats and harms. Pathogenic microorganisms, including bacteria, viruses, fungi, and parasites, are responsible for a wide array of diseases in humans, animals, and plants. They cause illnesses ranging from common infections to severe epidemics, pandemics, and crop devastation. Diseases like malaria, tuberculosis, influenza, and various foodborne illnesses result from harmful microorganisms. Moreover, some microorganisms can spoil food, contaminate water sources, and cause decay in materials, leading to economic losses and compromising public health. Additionally, antibiotic resistance, driven by the overuse of antibiotics, presents a global challenge, making it harder to treat infections effectively. Overall, while microorganisms offer immense benefits, their harmful aspects necessitate vigilant measures to mitigate their adverse impacts on society and ecosystems.
Questions 9
What are antibiotics? What precautions must be taken while taking antibiotics?
Answer – Antibiotics are powerful medications used to treat bacterial infections by either killing bacteria or inhibiting their growth. They’re essential in modern medicine for combating various bacterial diseases, from common infections like strep throat to more severe conditions such as pneumonia and bacterial meningitis.
When taking antibiotics, it’s crucial to follow certain precautions to ensure their effectiveness and minimize potential risks:
1. **Complete the Full Course:** Always finish the prescribed course of antibiotics, even if you start feeling better before completing it. Stopping early can lead to antibiotic resistance, where bacteria become less susceptible to the medication.
2. **Take as Directed:** Follow the dosage instructions provided by your healthcare provider. Don’t skip doses or take more than prescribed.
3. **Avoid Sharing or Saving Antibiotics:** Antibiotics are specific to the individual and condition for which they are prescribed. Don’t share antibiotics with others or save them for later use.
4. **Use with Caution:** Some antibiotics may interact with other medications, supplements, or foods. Inform your healthcare provider about any other medications or conditions you have.
5. **Watch for Side Effects:** Be aware of potential side effects such as allergic reactions, digestive issues, or skin rashes. Contact your healthcare provider if you experience severe side effects.
6. **Prevent Antibiotic Resistance:** Overuse or misuse of antibiotics can contribute to the development of antibiotic-resistant bacteria. Use antibiotics only when prescribed for bacterial infections, not for viral infections like colds or flu.
7. **Support with Probiotics:** Antibiotics can disrupt the balance of beneficial bacteria in your gut, leading to issues like diarrhea. Consider taking probiotics or consuming foods like yogurt to help restore this balance.
8. **Follow Up with Healthcare Provider:** If symptoms persist or worsen despite taking antibiotics, consult your healthcare provider. They might need to reassess your condition and possibly change the antibiotic or treatment plan.
Taking antibiotics responsibly and as directed by a healthcare professional is crucial to ensure their effectiveness and reduce the risk of antibiotic resistance.