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