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CBSE Class 8 Science Microorganisms: Friend and Foe Worksheets

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CBSE Class 8 Science Microorganisms: Friend and Foe Worksheets with Answers - Chapter 2 - PDF

Class 8 Students looking to freshen up their knowledge of Science Chapter 2 Microorganisms: Friend and Foe can download free printable worksheets just with a single click on the pdf link provided on this page. The worksheets are prepared by subject experts at Vedantu as per the latest CBSE exam patterns, syllabus, and guidelines issued by the CBSE board. Class 8 students should practice the worksheet to enhance their knowledge of all the topics covered in the chapter.  Read the article below to have a brief knowledge of the topics covered in the chapter.

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Introduction to Microorganisms

A microorganism is a microscopic living thing that we cannot see without using a microscope. Most of the microorganisms are either unicellular or multicellular.

Prokaryotes

Prokaryotes are microorganisms that do not have any membrane-bound nucleus and other organelles (e.g., mitochondria). Proteobacteria, Cyanobacteria, Actinobacteria, Chloroflexi, Thermodesulfobacteria, Thermotogae, Chlorobi, and Spirochaetes are some of the examples of prokaryotes. A prokaryote is a single-celled microorganism. So it does not have any membrane-bound nucleus or organelles like mitochondria or chloroplasts. They don't have the double lipid layer present in plant and animal cells.

Eukaryotes

Eukaryotes are organisms that have membrane-bound nuclei, distinct organelles like mitochondria, Golgi apparatus, etc., and some kind of cytoskeleton proteins. Plant, Animal, Fungi, Algae cells are eukaryotic cells.

Important Characteristics of Living Things

Life is a characteristic that distinguishes physical entities that have signaling and self-sustaining processes from those which do not, either because such functions have ceased (death) or else because they lack such functions and are classified as inanimate.

Microorganisms and Disease

Prokaryotes are responsible for diseases that have two characteristics. One is that they are infectious, i.e., they can be passed from one organism to another. Second, the infecting organism multiplies inside its host and causes harm or illness to it.

LPS

Lipopolysaccharides (or simply LPS) are endotoxins that are released from the outer membrane of gram-negative bacteria. These endotoxins are responsible for the symptoms of sepsis and septic shock.

Vaccine

A vaccine is a preparation of dead or weakened microorganisms which is used to protect against infection by that microorganism. Vaccines can be prophylactic (for example: against polio or smallpox) or therapeutic (against a disease already present in the body, such as various forms of cancer).

Antibiotics

Antibiotics are substances that kill bacteria and other microorganisms without harming the host. These include a wide range of synthetic and naturally produced chemicals with different types of biological activities. 

Do All Antibiotics Kill Bacteria?

No, not all antibiotics kill bacteria. Some of them just stop the bacteria from multiplying, while others can actually change the structure of the bacterial cell wall, making it more permeable. This makes it easier for the body's own immune system to destroy the bacterium.

Importance of CBSE Class 8 Chapter 2 Worksheets Free PDF

Worksheet plays a significant role in a student's exam preparation. CBSE Class 8 Chapter worksheet is an ideal and exciting way to learn about microorganisms. It also provides great opportunities to kids to practice their reading skills, writing skills, solving questions related to the chapter, and more. It also helps parents to track how well their child knows about the chapter. Vedantu provides the Class 8 Science Chapter 2 worksheet for free to download so that students can prepare for their exam efficiently.

Conclusion

Along with the worksheets, the students can also download all the free material like sample papers, previous years’ question papers, revision notes, etc on Vedantu. Vedantu believes in providing hassle-free and accessible learning experiences to the students who are willing to learn and grow their knowledge. Students can download all this material for free by registering on Vedantu and searching for the respective study material. With the help of Vedantu, students can excel in their examinations and get a good overall learning experience.  

FAQs on CBSE Class 8 Science Microorganisms: Friend and Foe Worksheets

1. What are Microorganisms as discussed in chapter 2 of CBSE Class 8 Science?

Microorganisms are tiny living things that can only be seen with a microscope. They are so small that they can't be seen with the naked eye and can only be seen through a microscope. There are many kinds of microorganisms, including bacteria, fungi, and viruses. These microorganisms are very important to our everyday lives. Some microorganisms are helpful, while others are harmful. Helpful microorganisms are called 'probiotics,' while harmful microorganisms are called 'pathogens.' These pathogens are very important because they cause diseases that are very harmful to us.

2. What is an example of pathogens as discussed in chapter 2 of CBSE Class 8 Science?

The most common examples are bacteria, fungi, and viruses, which cause many diseases in plants, animals, and humans, respectively. Some other pathogenic microorganisms are protozoa, helminths (worms), chlamydiae, rickettsiae, mycoplasma, and spirochetes. Pathogens produce very serious diseases in humans, such as typhoid fever, tuberculosis, AIDS, and cholera. Beneficial microorganisms are those that have a beneficial effect on human or animal health, for example, by inhibiting the growth of harmful microorganisms or by synthesizing vitamins. Probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit on the host.

3. How can microorganisms be helpful according to chapter 2 of CBSE Class 8 Science?

There are many ways in which microorganisms can be helpful. For example, some microorganisms are used to produce food, such as yogurt, cheese, and bread. Others are used to produce medicines, such as antibiotics. Microorganisms can also be used to clean up pollution, for example, by breaking down oil spills. Finally, microorganisms can also be used to produce energy, for example, by turning sugar into ethanol which helps in the running of automobiles. Microorganisms are very helpful for us in many ways, for example by producing food such as bread and cheese.

4. What are bacteria according to chapter 2 of CBSE Class 8 Science?

Bacteria are one-celled microorganisms, and a few types cause disease in humans and other animals. Usually, bacteria can be found in soil, water, dust, and the intestines of humans and other animals. Sometimes bacteria cause infections in plants too. Many kinds of bacteria are helpful; for example, some are used to make yogurt and cheese. These bacteria are called probiotics. With the help of these probiotics, people can get more vitamins and minerals. With the help of these minerals and vitamins, people can get healthy.

5. What is the difference between a bacterium and a virus according to chapter 2 of CBSE Class 8 Science?

A bacteria and a virus are both microorganisms. They differ mainly in their genetic material. Bacteria generally contain nucleic acids (DNA or RNA), whereas viruses consist of either DNA or RNA that is surrounded by a protein coat. Virus particles cannot reproduce themselves without taking over the host cell. Viruses are infectious agents that consist of genetic material (DNA or RNA) surrounded by a coating of protein. Bacteria are microscopic single-celled organisms lacking the ability to self-propagate without being hijacked by another organism, which is called bacterial conjugation.